{"train_titles": ["Global coronal seismology", "The Infrared Cloud Monitor for the MAGNUM Robotic Telescope at Haleakala", "Two new basaltic asteroids in the Outer Main Belt?", "X-ray Timing Observations of PSR J1930+1852 in the Crab-like SNR\n  G54.1+0.3", "Heterogeneous condensation on the centers with continuous activity in\n  dynamic conditions", "The integral equation approach to kinematic dynamo theory and its\n  application to dynamo experiments in cylindrical geometry", "Pulsar radiation belts and transient radio emission", "New way to achieve chaotic synchronization in spatially extended systems", "A Study of Catalogued Nearby Galaxy Clusters in the SDSS-DR4: I. Cluster\n  Global Properties", "ALMA : Fourier phase analysis made possible", "Localization of acoustic waves in 1D random liquid media", "On a multi-resonant origin of high frequency quasiperiodic oscillations\n  in the neutron-star X-ray binary 4U 1636-53", "The effect of supernova asymmetry on coalescence rates of binary neutron\n  stars", "Acoustic wave propagation in an one-dimensional layered system", "Vibrational properties of the one-component $\\sigma$ phase", "A Dark Energy model combining DGP gravity and Chaplygin gas", "Non-ergodic effects in the Coulomb glass: specific heat", "VIMOS-VLT spectroscopy of the giant Ly-alpha nebulae associated with\n  three z~2.5 radio galaxies", "d_{x^2-y^2} pairing of composite excitations in the 2D Hubbard model", "Characterization of Instrumental Phase Stability", "Liquid-Solid Transition of Hard Spheres Under Gravity", "Modeling the Spectral Energy Distribution and Variability of 3C 66A\n  during the WEBT campaign of 2003 -- 2004", "Mapping the circumstellar SiO maser emission in R Leo", "Gravitational waves from galaxy encounters", "The Search for Primordial Black Holes Using Very Short Gamma Ray Bursts", "Hydrodynamical simulations of the jet in the symbiotic star MWC 560 III.\n  Application to X-ray jets in symbiotic stars", "Bar-Halo Friction in Galaxies III: Particle Number Requirements for\n  Simulations", "The Habitat Segregation between Lyman Break Galaxies and Lyman alpha\n  Emitters around a QSO at z~5", "The Physical Nature of Polar Broad Absorption Line Quasars", "Electronic Ladders with SO(5) Symmetry: Phase Diagrams and Correlations\n  at half-filling", "Statics and dynamics of domain patterns in hexagonal-orthorhombic\n  ferroelastics", "IRAC Observations of CO J=4-3 High-Velocity Cloud in the 30 Doradus\n  Complex in the Large Magellanic Cloud", "Multispecies reaction-diffusion systems", "Nonlinear transport theory for hybrid normal-superconducting devices", "Limits on the Curie temperature of (III,Mn)V ferromagnetic\n  semiconductors", "Local magnetic properties of periodic nonuniform spin-1/2 XX chains", "GRB 050826: A Subluminous Event at z = 0.296 Finds its Place in the\n  Luminosity Distribution of Gamma-Ray Burst Afterglows", "Mass loss from Luminous Blue Variables and Quasi-Periodic Modulations of\n  Radio Supernovae", "How Mergers May Affect The Mass Scaling Relations Between Black Holes,\n  Galaxies, and Other Gravitationally Bound Systems", "Chromospheric Flares", "Chandra Observations of Supernova 1987A", "The Star-forming Region NGC 346 in the Small Magellanic Cloud with\n  Hubble Space Telescope ACS Observations. II. Photometric Study of the\n  Intermediate-Age Star Cluster BS 90", "Semiclassical theory of trapped fermionic dipoles", "Response-theory for nonresonant hole burning: Stochastic dynamics", "Neutron-Capture Elements in the Double-Enhanced Star HE 1305-0007: a New\n  s- and r-Process Paradigm", "Wetting transitions of He4 on alkali metal surfaces from density\n  functional calculations", "The time evolution of cosmological redshift as a test of dark energy", "Electronic Properties of Ultra-Thin Aluminum Nanowires", "Exciting the Magnetosphere of the Magnetar CXOU J164710.2-455216 in\n  Westerlund 1", "Diabolical points in the magnetic spectrum of Fe_8 molecules", "The Magnetic Fields of Classical T Tauri Stars", "Weakly-interacting Bose-Einstein condensates under rotation", "Vibration-induced \"thermally activated\" jamming transition in granular\n  media", "The Millennium Galaxy Catalogue: The local supermassive black hole mass\n  function in early- and late-type galaxies", "The Theory of Atom Lasers", "Stochastics theory of log-periodic patterns", "Magnetorotational Collapse of Population III Stars", "Atomic Solitons in Optical Lattices", "Eliminating the mean-field shift in multicomponent Bose-Einstein\n  condensates", "Mapping the Youngest Galaxies to Redshift One", "Exact Eigenstates for Repulsive Bosons in Two Dimensions", "Multidimensional supernova simulations with approximative neutrino\n  transport. II. Convection and the advective-acoustic cycle in the supernova\n  core", "Front propagation into unstable states: Universal algebraic convergence\n  towards uniformly translating pulled fronts", "Shaping the Globular Cluster Mass Function by Stellar-Dynamical\n  Evaporation", "Ising Model and L - Function", "Evidence for a merger of binary white dwarfs: the case of GD 362", "Solving the phase problem in i(AlPdMn)", "XMM-Newton view of galaxy pairs: activation of quiescent black holes?", "Wannier Functions for Lattices in a Magnetic Field II: Extensions to\n  Irrational Fields", "Novel type of orbital ordering: complex orbitals in doped Mott\n  insulators", "Directed Relativistic Blast Wave", "Relaxation Processes in Administered-Rate Pricing", "Magnetic properties of a new molecular-based spin-ladder system:\n  (5IAP)2CuBr4*2H2O", "Studying Reionization with Ly-alpha Emitters", "Stable 85Rb Bose-Einstein Condensates with Widely Tunable Interactions", "On the Prospects for Detection and Identification of Low-Frequency\n  Oscillation Modes in Rotating B Type Stars", "Dynamics of Excited Electrons in Copper: Role of Auger Electrons", "The SAURON project - XI. Stellar Populations from Absorption Line\n  Strength Maps of 24 Early-Type Spirals", "Analysis of g_2 for the cold-collision frequency shift in the hydrogen\n  condensate experiments", "Complex impedance measurements of calorimeters and bolometers:\n  correction for stray impedances", "The Mass and Radius of the Unseen M-Dwarf Companion in the Single-Lined\n  Eclipsing Binary HAT-TR-205-013", "Low-Lying Excitations from the Yrast Line of Weakly Interacting Trapped\n  Bosons", "Decay of metastable phase on several types of heterogeneous centers", "A Possible Stellar Metallic Enhancement in Post-T Tauri Stars by a\n  Planetesimal Bombardment", "Dephasing times in quantum dots due to elastic LO phonon-carrier\n  collisions", "Implementation of a Gauss convoluted Pandel PDF for track reconstruction\n  in Neutrino Telescopes", "Fredholm determinant representation for the partition function of the\n  six-vertex model", "The Reverse Shock of SNR 1987A", "Gamma-ray probe of the QSO's obscured evolution", "Spin waves in ultrathin ferromagnetic overlayers", "Oscillations of rotating trapped Bose-Einstein condensates", "Magneto infra-red absorption in high electronic density GaAs quantum\n  wells", "The Cornell Caltech Atacama Telescope", "Temperature Dependent Scattering Rates at the Fermi Surface of Optimally\n  Doped Bi 2212", "A cluster algorithm for Potts models with fixed spin densities", "PdBI sub-arcsecond study of the SiO microjet in HH212 - Origin and\n  collimation of Class 0 jets", "Magnetic Behavior of a Mixed Ising Ferrimagnetic Model in an Oscillating\n  Magnetic Field", "Exchange Field Induced Magnetoresistance in Colossal Magnetoresistance\n  Manganites", "Comment on \"Observation of Spin Injection at a Ferromagnet-Semiconductor\n  Interface, by P.R. Hammar et al", "Quantum-Mechanical Non-Perturbative Response of Driven Chaotic\n  Mesoscopic Systems", "The Na I D resonance lines in main sequence late-type stars", "Collisional damping of the collective oscillations of a trapped Fermi\n  gas", "Point contact tunneling in the fractional quantum Hall effect: an exact\n  determination of the statistical fluctuations", "The LuckyCam Survey for Very Low Mass Binaries II: 13 new M4.5-M6.0\n  Binaries", "Recent Developments in Maser Theory", "Multi-wavelength Analysis of a Quiet Solar Region", "Landau and Dynamical Instabilities of the Superflow of Bose-Einstein\n  Condensates in Optical Lattices", "Distinguishing fractional and white noise in one and two dimensions", "Ratchet effect in dc SQUIDs", "Diffusion with rearranging traps", "The remarkable X-ray spectrum of the Broad-Line Radio Galaxy 3C 445", "Criteria in the Selection of Target Events for Planetary Microlensing\n  Follow-Up Observation", "The multiplicity of planet host stars - New low-mass companions to\n  planet host stars", "Hedging large risks reduces the transaction costs", "Distributions of H2O and CO2 ices on Ariel, Umbriel, Titania, and Oberon\n  from IRTF/SpeX observations", "Reactive Hall response", "Kinetic Theory of Collective Excitations and Damping in Bose-Einstein\n  Condensed Gases", "Mixed chemistry phenomenon during late stages of stellar evolution", "Simulation of Stochastic Volatility using Path Integration: Smiles and\n  Frowns", "The effect of the solar corona on the attenuation of small-amplitude\n  prominence oscillations. I. Longitudinal magnetic field", "Superfluid Helium 3: Link between Condensed Matter Physics and Particle\n  Physics", "Testing the gamma-ray burst variability/peak luminosity correlation on a\n  Swift homogeneous sample", "Radio Astrometric Detection and Characterization of Extra-Solar Planets:\n  A White Paper Submitted to the NSF ExoPlanet Task Force", "A New Model For The Loop-I (The North Polar Spur) Region", "Comprehensive simulations of superhumps", "Hypervelocity stars and the environment of Sgr A*", "The M33 Variable Star Population Revealed by Spitzer", "Mechanical detection of nuclear spin relaxation in a micron-size crystal", "Ferromagnetism and Canted Spin Phase in AlAs/GaMnAs Single Quantum\n  Wells: Monte Carlo Simulation", "Interacting random Dirac fermions in superconducting cuprates", "Self-Duality in Superconductor-Insulator Quantum Phase Transitions", "Witnessing the formation of a galaxy cluster at z=0.485: optical and\n  X-ray properties of RX J1117.4+0743 ([VMF 98] 097)", "Rapidly Rotating Fermi Gases", "Exploring First Stars Era with GLAST", "A CF3I-based SDD Prototype for Spin-independent Dark Matter Searches", "Molecular motor that never steps backwards", "Structure and rheology of binary mixtures in shear flow", "A binary model for the UV-upturn of elliptical galaxies (MNRAS version)", "Resolving the pulsations of subdwarf B stars: HS 0039+4302, HS\n  0444+0458, and an examination of the group properties of resolved pulsators", "Topological defect system in O(n) symmetric time-dependent\n  Ginzburg-Landau model", "Developing the Galactic diffuse emission model for the GLAST Large Area\n  Telescope", "The Mid-Infrared Emission of M87", "Structure of binary Bose-Einstein condensates", "Off equilibrium properties of vortex creep in superconductors", "X-ray emission from the planet pulsar B1257+12", "Description of Dynamic Properties of Finite Electron Systems in Density\n  Functional Theory", "Long Gamma-Ray Burst Progenitors: Boundary Conditions and Binary Models", "A Model for Addition Spectra in Quantum Dots", "Description of the Scenario Machine", "Blazar surveys with WMAP and Swift", "X-Raying the MOJAVE Sample of Compact Extragalactic Radio Jets", "Dust covering factor, silicate emission and star formation in luminous\n  QSOs", "Lattice Boltzmann simulations of segregating binary fluid mixtures in\n  shear flow", "Ferromagnetic ordering in a generalized Hubbard model: weak intra-atomic\n  interaction limit", "Predicting the frequencies of diverse exo-planetary systems", "Spitzer Mid-Infrared Spectroscopy of Infrared Luminous Galaxies at z~2\n  II: Diagnostics", "Chromospheric Cloud-Model Inversion Techniques", "Cold Trapped Atoms: A Mesoscopic System", "Interplay of real space and momentum space topologies in strongly\n  correlated fermionic systems", "Temperature effect in the Casimir attraction of a thin metal film", "Surface collective excitations in ultrafast pump-probe spectroscopy of\n  metal nanoparticles", "Simulation of Ultra High Energy Neutrino Interactions in Ice and Water", "Induced instability for boson-fermion mixed condensate of Alkali atoms\n  due to attractive boson-fermion interaction", "Jet interactions in massive X-ray binaries", "Superconductor-Insulator Quantum Phase Transitions", "Galaxy Evolution and Environment", "Mapping the Cosmological Confidence Ball Surface", "Proper Motion Dispersions of Red Clump Giants in the Galactic Bulge:\n  Observations and Model Comparisons", "Are \"EIT Waves\" Fast-Mode MHD Waves?", "Transport Properties of Highly Aligned Polymer Light-Emitting-Diodes", "Star Formation in the Bok Globule CB54", "Membrane boundary condition", "Measuring the dark side (with weak lensing)", "Hamiltonian structure of thermodynamics with gauge", "Strong Confinement and Oscillations in Two-Component Bose-Einstein\n  Condensates", "3D Radiative Hydrodynamics for Disk Stability Simulations: A Proposed\n  Testing Standard and New Results", "Near-Infrared Spectra of the Black Hole X-Ray Binary, A0620-00", "Analysis of Dislocation Mechanism for Melting of Elements: Pressure\n  Dependence", "Evolution of Magnetic Fields in Stars Across the Upper Main Sequence:\n  II. Observed distribution of the magnetic field geometry", "One-Dimensional Textures and Critical Velocity in Superfluid 3He-A", "Magnetic Field Effect for Two Electrons in a Two Dimensional Random\n  Potential", "Finite temperature oscillations of a Bose-Einstein condensate in a\n  two-gas model", "Crossover from percolation to diffusion", "Macroscopic Quantum Phase Interference in Antiferromagnetic Particles", "A ^4He shadow wavefunction with an inverse seventh power\n  particle-particle correlation function", "Three Different Types of Galaxy Alignment within Dark Matter Halos", "Dust and gas emission in the prototypical hot core G29.96-0.02 at\n  sub-arcsecond resolution", "Adiabatic compression of a trapped Fermi gas", "X-ray source counts in the COSMOS field", "Proto-Neutron Star Winds, Magnetar Birth, and Gamma-Ray Bursts", "Light curves and colours of the faint Uranian irregular satellites\n  Sycorax, Prospero, Stephano, Setebos and Trinculo", "Chemical Evolution", "Bose-Einstein condensation in trapped dipolar gases", "Relation between Raman spectra and Structure of Amorphous Silicon", "An absorption origin for the soft excess in Seyfert 1 AGN", "Dynamic splitting of a Bose-Einstein Condensate", "SUBARU HDS Observations of a Balmer-Dominated Shock in Tycho's Supernova\n  Remnant", "Mean parameter model for the Pekar-Fr\\\"{o}hlich polaron in a\n  multilayered heterostructure", "Thermopower in p-type GaAs/AlGaAs layers", "Glassy effects in the swelling/collapse dynamics of homogeneous polymers", "Quenching and Annealing in the Minority Game", "Modeling the Solar Chromosphere", "Atomic four-wave mixing: fermions versus bosons", "Sulphur abundances from the SI near-infrared triplet at 1045 nm", "Warm HCN, C2H2, and CO in the disk of GV Tau", "An Extrasolar Planet Census with a Space-based Microlensing Survey", "Atom loss and the formation of a molecular Bose-Einstein condensate by\n  Feshbach resonance", "Three-dimensional vortex dynamics in Bose-Einstein condensates", "Diagonalization of a bosonic quadratic form using CCM: Application on a\n  system with two interpenetrating square lattice antiferromagnets", "Vortex shedding and drag in dilute Bose-Einstein condensates", "Geometry dominated fluid adsorption on sculptured substrates", "High Energy Afterglow from Gamma-ray Bursts", "Coherent electron-phonon coupling and polaron-like transport in\n  molecular wires", "Relativistic stabilisation of the diocotron instability in a pulsar\n  \"cylindrical\" electrosphere", "Sonoluminescence as a Physical Vacuum Excitation", "Non-spiky density of states of an icosahedral quasicrystal", "s+d pairing in orthorhombic phase of copper-oxides", "Constraints on the Interactions between Dark Matter and Baryons from the\n  X-ray Quantum Calorimetry Experiment", "Off-axis vortices in trapped Bose condensed gases: angular momentum and\n  frequency splitting", "Gemini Spectroscopic Survey of Young Star Clusters in\n  Merging/Interacting Galaxies. II. NGC 3256 Clusters", "The VIMOS VLT Deep Survey. The Assembly History of the Stellar Mass in\n  Galaxies: from the Young to the Old Universe", "Displacement of the Sun from the Galactic Plane", "Massive Stars: From the VLT to the ELT", "Segregation transitions in wet granular matter", "Effects of the galactic winds on the stellar metallicity distribution of\n  dwarf spheroidal galaxies", "Random Dirac Fermions: The su(N) Gauge Potential and Z_N Twists", "Dynamical Complexity, Intermittent Turbulence, Coarse-Grained\n  Dissipation, Criticality and Multifractal Processes", "A method for the direct determination of the surface gravities of\n  transiting extrasolar planets", "On direction of spontaneous magnetization in a \"cubic\" ferromagnet", "Vortex nucleation and hysteresis phenomena in rotating Bose-Einstein\n  condensates", "Imaging the Ionized Disk of the High-Mass Protostar Orion-I", "Near- and Far-Infrared Counterparts of Millimeter Dust Cores in the Vela\n  Molecular Ridge Cloud D", "Photometry of the SW Sex-type nova-like BH Lyncis in high state", "Ising films with surface defects", "Three-loop critical exponents, amplitude functions, and amplitude ratios\n  from variational perturbation theory", "Self-Similar Crossover in Statistical Physics", "Star-Formation in Low Radio Luminosity AGN from the Sloan Digital Sky\n  Survey", "On spherically symmetrical accretion in fractal media", "On the Bragg, Leibfried, and Modified Leibfried Numbers", "Regular and Anomalous Quantum Diffusion in the Fibonacci Kicked Rotator", "A renormalized expression for the turbulent energy dissipation rate", "Scaling properties of scale-free evolving networks: Continuous approach", "The Transition from the First Stars to the Second Stars in the Early\n  Universe", "A Cascade Model for Particle Concentration and Enstrophy in Fully\n  Developed Turbulence with Mass Loading Feedback", "Complete determination of the reflection coefficient in neutron specular\n  reflection by absorptive non-magnetic media", "Feedback from first radiation sources: H- photodissociation", "The Spitzer c2d Survey of Large, Nearby, Insterstellar Clouds. IX. The\n  Serpens YSO Population As Observed With IRAC and MIPS", "Cryptoplanet update", "Spin bath-mediated decoherence in superconductors", "Jeans instability of a galactic disk embedded in a live dark halo", "Field-dependence of the Magnetic Relaxation in Mn12-Acetate: A New Form\n  of Spectroscopy", "Existence and stability of atomic-molecular Bose-Einstein condensates", "On the evaluation of the specific heat and general off-diagonal n-point\n  correlation functions within the loop algorithm", "Observations of chemical differentiation in clumpy molecular clouds", "Quantized Vorticity in Superfluid 3He-A", "Comment on \"Quantum diffusion of 3-He impurities in solid 4- He\"", "A new application of reduced Rayleigh equations to electromagnetic wave\n  scattering by two-dimensional randomly rough surfaces", "On the orbital period of the magnetic Cataclysmic Variable HS 0922+1333", "The white dwarf luminosity function --II. The effect of the measurement\n  errors and other biases", "Compton-thick AGN and the Synthesis of the Cosmic X-ray Background: the\n  Suzaku Perspective", "Models for Free Granular Surfaces", "Quasiparticle kinetic equation in a trapped Bose gas at low temperatures", "Why do some intermediate polars show soft X-ray emission? A survey of\n  XMM-Newton spectra", "The ground state properties of the spin-1/2 transverse Ising chain with\n  periodically varying bonds and fields", "Frequency Dependent Viscosity Near the Critical Point: The Scale to Two\n  Loop Order", "Zero temperature correlations in trapped Bose-Einstein condensates", "A novel method for the extraction of the condensate fraction of liquid\n  ^4He", "Exploring Infrared Properties of Giant Low Surface Brightness Galaxies", "INTEGRAL observations of HER X-1", "Possible origin of Larson's lows", "A large scale extinction map of the Galactic Anticenter from 2MASS", "Equilibrium crystal shapes in the Potts model", "Topology of HI in the Large Magellanic Cloud", "Nonlinear Effect of Transport Current on Response of Metals to\n  Electromagnetic Radiation", "Periodic accretion from a circumbinary disk in the young binary UZ Tau E", "Analytical Estimate of the Critical Velocity for Vortex Pair Creation in\n  Trapped Bose Condensates", "d- and p-wave superconductivity mediated by spin fluctuations in two-\n  and three-dimensional single-band repulsive Hubbard model", "Investigation of Energy Spectrum of EGRET Gamma-ray Sources by an\n  Extensive Air Shower Experiment", "Adsorption of benzene on Si(100) from first principles", "Second Topological Moment < m^2 > of Two Closed Entangled Polymers", "Direct Minimization Generating Electronic States with Proper Occupation\n  Numbers", "The Rotation of Sub-Populations in omega Centauri", "The molecular environment of massive star forming cores associated with\n  Class II methanol maser emission", "Dust Formation and Survival in Supernova Ejecta", "Time evolution of tetragonal-orthorhombic ferroelastics", "Retired A Stars and Their Companions: Exoplanets Orbiting Three\n  Intermediate-Mass Subgiants", "The Volatility in a Multi-share Financial Market Model", "Second-order perturbations of cosmological fluids: Relativistic effects\n  of pressure, multi-component, curvature, and rotation", "The Density Profile of Local Ellipticals as Violently Relaxed,\n  Collisionless, Dissipationless Systems", "Smooth and Starburst Tidal Tails in the GEMS and GOODS Fields", "A computer program for fast non-LTE analysis of interstellar line\n  spectra", "An Efficient and Robust Technique for Achieving Self Consistency in\n  Electronic Structure Calculations", "Characterization of open cluster remnants", "Reversible and irreversible evolution of a condensed bosonic gas", "Magnetic properties of the S=1/2 quasi-one-dimensional antiferromagnet\n  CaCu2O3", "A Jet-like Outflow toward the High-Mass (Proto)stellar Object IRAS\n  18566+0408", "Approximate formula for the ground state energy of anyons in 2D\n  parabolic well", "Effects of a pre-inflation radiation-dominated epoch to CMB anisotropy", "Testing Disk Instability Models for Giant Planet Formation", "Radiative losses and cut-offs of energetic particles at relativistic\n  shocks", "Timing evidence in determining the accretion state of the Seyfert galaxy\n  NGC 3783", "An SiO Maser Search off the Galactic Plane", "High-Energy Calibration of a BGO detector of the GLAST Burst Monitor", "The Connection between Star-Forming Galaxies, AGN Host Galaxies and\n  Early-Type Galaxies in the SDSS", "Absolute Calibration and Characterization of the Multiband Imaging\n  Photometer for Spitzer. II. 70 micron Imaging", "Parametric Quantum Resonances for Bose-Einstein Condensates", "Comment on: \"Phenomenological model of Dynamic Nonlinear Response in\n  Relaxor Ferroelectrics", "Optical Multicolor Photometry of Spectrophotometric Standard Stars", "Electron-phonon interaction in C70", "Indivisibility of electron bubbles in helium", "Parent Stars of Extrasolar Planets. VIII. Chemical Abundances for 18\n  Elements in 31 Stars", "Fluctuation Pressure of a Stack of Membranes", "A Bosonic Model of Hole Pairs", "Three Years of Mira Variable CCD Photometry: What Has Been Learned?", "Acetylene on Si(100) from first principles: adsorption geometries,\n  equilibrium coverages and thermal decomposition", "Time correlations of a laser-induced Bose-Einstein condensate", "Structural, Electronic, and Magnetic Properties of MnO", "Diffuse X-ray Emission from the Carina Nebula Observed with Suzaku", "Breakdown of the standard Perturbation Theory and Moving Boundary\n  Approximation for \"Pulled\" Fronts", "A physicist's approach to number partitioning", "Molecular dynamics simulations of lead clusters", "Effects of spin-elastic interactions in frustrated Heisenberg\n  antiferromagnets", "Multifractal behavior of linear polymers in disordered media", "Option Pricing and Hedging with Temporal Correlations", "Quasicondensate and superfluid fraction in the 2D charged-boson gas at\n  finite temperature", "Giant negative magnetoresistance in semiconductors doped by multiply\n  charged deep impurities", "Investigation of transit-selected exoplanet candidates from the MACHO\n  survey", "Possible X-ray diagnostic for jet/disk dominance in Type 1 AGN", "The Peculiar Velocities of Local Type Ia Supernovae and their Impact on\n  Cosmology", "Fundamental Plane of Sunyaev-Zeldovich clusters", "Binaries, microquasars and GLAST", "Atomic Deuterium Adsorbed on the Surface of Liquid Helium", "Hydrogen 2p--2s transition: signals from the epochs of recombination and\n  reionization", "The nature of a broad line radio galaxy: Simultaneous RXTE and Chandra\n  HETG observations of 3C 382", "Theory of the spin bath", "Wormholes in the accelerating universe", "Optical spectrum of the post-AGB star HD56126 in the region 4010-8790 AA", "The VVDS type-1 AGN sample: The faint end of the luminosity function", "The Low CO Content of the Extremely Metal Poor Galaxy I Zw 18", "Possible non-thermal nature of the soft-excess emission in the cluster\n  of galaxies Sersic 159-03", "Measuring energy dependent polarization in soft gamma-rays using Compton\n  scattering in PoGOLite", "Motion of an object through a dilute quantum fluid", "Large Scale Self-Similar Skeletal Structure of the Universe", "Ab initio treatment of electron correlations in polymers: lithium\n  hydride chain and beryllium hydride polymer", "PAH Strength and the Interstellar Radiation Field around the Massive\n  Young Cluster NGC3603", "HST/ACS Coronagraphic Observations of the Dust Surrounding HD 100546", "Dislocation-Mediated Melting: The One-Component Plasma Limit", "Electronic transport in strongly anisotropic disordered systems: model\n  for the random matrix theory with non-integer beta", "Cavity assisted quasiparticle damping in a Bose-Einstein condensate", "Geometrical Approach for the Mean-Field Dynamics of a Particle in a\n  Short Range Correlated Random Potential", "Star Formation and the Growth of Stellar Mass", "Formation of Pairing Fields in Resonantly Coupled Atomic and Molecular\n  Bose-Einstein Condensates", "An entropy-driven noise-induced phase transition", "VLBI detection of an Infrared-Faint Radio Source", "The angular correlations of galaxies in the COSMOS field", "Multi-wavelength observations of Southern Hot Molecular Cores traced by\n  methanol masers - I. Ammonia and 24 GHz Continuum Data", "Radio and X-ray nebulae associated with PSR J1509-5850", "Modelling the Galactic bar using OGLE-II Red Clump Giant Stars", "Renormalization Group and Probability Theory", "Does the Blazar Gamma-Ray Spectrum Harden with Increasing Flux? Analysis\n  of 9 Years of EGRET Data", "The collision velocity of the bullet cluster in conventional and\n  modified dynamics", "Direct observation of growth and collapse of a Bose-Einstein condensate\n  with attractive interactions", "The exceptionally extended flaring activity in the X-ray afterglow of\n  GRB 050730 observed with Swift and XMM-Newton", "An online repository of Swift/XRT light curves of GRBs", "Condensate Oscillations, Kinetic Equations and Two-Fluid Hydrodynamics\n  in a Bose Gas", "Cosmological Shock Waves in the Large Scale Structure of the Universe:\n  Non-gravitational Effects", "Molecular line intensities as measures of cloud masses - II. Conversion\n  factors for specific galaxy types", "Phases of a Stack of Membranes at Large-d", "3d Numerical Models of the Chromosphere, Transition Region, and Corona", "Relationship between spiral and ferromagnetic states in the Hubbard\n  model in the thermodynamic limit", "Concentration-Pressure phase diagram for rich Zr PZT ceramics", "MS 2053.7-0449: Confirmation of a bimodal mass distribution from strong\n  gravitational lensing", "Fine structure of excitons in a quantum well in the presence of a\n  nonhomogeneous magnetic field", "Creation of Skyrmions in a Spinor Bose-Einstein Condensate", "Quantum radiative corrections to slow-roll inflation", "Interpreting and predicting the yield of transit surveys: Giant planets\n  in the OGLE fields", "U Geminorum: a test case for orbital parameters determination", "Universality classes of driven lattice gases", "Generalized quasiperiodic Rauzy tilings", "Hall effect in the cuprates: the role of forward scattering on\n  impurities", "Magnetostriction and magnetoelastic domains in antiferromagnets", "On the Critical Ionization Velocity Effect in Interstellar Space and\n  Possible Detection of Related Continuum Emission", "ALMA as the ideal probe of the solar chromosphere", "A supersymmetric mean-field approach to the infinite-U Hubbard model", "HI velocity dispersion in NGC 1058", "The Sensitivity of Hybrid Differential Stereoscopy for Spectral Imaging", "Torsional oscillations of longitudinally inhomogeneous coronal loops", "Zero-temperature equation of state of quasi-one dimensional H2", "Incipient nodal pairing in planar d-wave superconductors", "The impact of radio feedback from active galactic nuclei in cosmological\n  simulations: Formation of disk galaxies", "Friedel Oscillations and Charge-density Waves Pinning in\n  Quasi-one-dimensional Conductors: An X-ray Access", "Phase behaviour of a hard sphere colloidal system in the presence of an\n  external laser field", "Thermodynamic properties of confined interacting Bose gases - a\n  renormalization group approach", "Carrier relaxation with LO phonon decay in semiconductor quantum dots", "Projecting the Kondo Effect: Theory of the Quantum Mirage", "Master Equation for Electromagnetic Dissipation and Decoherence of\n  Density Matrix", "Magnetohydrodynamic Rebound Shocks of Supernovae", "Metal and molecule cooling in simulations of structure formation", "Interaction of Supernova Ejecta with Nearby Protoplanetary Disks", "Ultraviolet Observations of Supernovae", "Statistical properties of giant pulses from the Crab pulsar", "Current bistability and hysteresis in strongly correlated quantum wires", "Many-body diagrammatic expansion in a Kohn-Sham basis: implications for\n  Time-Dependent Density Functional Theory of excited states", "Phase ordering at the lambda transition in liquid 4-He", "CCD BV survey of 42 open clusters", "Electronic structure of polychiral carbon nanotubes", "Evidence for Pre-SN Mass Loss in the Galactic SNR 3C 58", "Efficient Simulations of Early Structure Formation and Reionization", "Long Term Simulations Of Astrophysical Jets; Energy Structure and\n  Quasi-Periodic Ejection", "Millimeter imaging of HD 163296: probing the disk structure and\n  kinematics", "The Solar Neighborhood. XIX. Discovery and Characterization of 33 New\n  Nearby White Dwarf Systems", "SDSS J233325.92+152222.1 and the evolution of intermediate polars", "Bose-Einstein condensates in standing waves: The cubic nonlinear\n  Schroedinger equation with a periodic potential", "Many-Electron wave function and momentum density", "Scaling Limits for the 2D Metal-Insulator Transition at B = 0 in\n  Si-MOSFETs", "Collective Modes of Trapped Fermi Gases in the Normal Phase", "Two-magnon Raman scattering in insulating cuprates: Modifications of the\n  effective Raman operator", "Comment on \"Models of Intermediate Spectral Statistics\"", "The colour selection of distant galaxies in the UKIDSS Ultra-Deep Survey\n  Early Data Release", "Probing the Structure of Gamma-Ray Burst Jets with Steep Decay Phase of\n  their Early X-ray Afterglows", "Does EELS haunt your photoemission measurements?", "Liquid-Solid Phase Transition of the System with Two particles in a\n  Rectangular Box", "Common Envelope Evolution Redux", "Equation of State in Relativistic Magnetohydrodynamics: variable versus\n  constant adiabatic index", "Further Evidence that the Redshifts of AGN Galaxies May Contain\n  Intrinsic Components", "A search for OH 6 GHz maser emission towards southern supernova remnants", "Experimental Evidence for Electron Channelling in Fe/Au (100)\n  Multilayers", "Finding Solar System Analogs With SIM and HIPPARCOS: A White Paper for\n  the ExoPlanet Task Force", "Dramatic Variability of X-ray Absorption Lines in the Black Hole\n  Candidate Cygnus X-1", "Bag Formation in Quantum Hall Ferromagnets", "A simple interpretation of quantum mirages", "Optics with an Atom Laser Beam", "CaB_6: a new semiconducting material for spin electronics", "The 1 keV to 200 keV X-ray Spectrum of NGC 2992 and NGC 3081", "Phase transitions and noise crosscorrelations in a model of directed\n  polymers in a disordered medium", "Cool objects: From SED fitting to age estimation", "GREGOR: the New German Solar Telescope", "Supersymmetry in Thermo Field Dynamics", "Observations of Manifestations of Skeletal Structures of a Filamentary\n  Matter on the Sun", "HS1857+5144: A hot and young pre-cataclysmic variable", "SBF: multi-wavelength data and models", "TEXES Observations of Pure Rotational H2 Emission From AB Aurigae", "Kinetics of Strongly Non-Equilibrium Bose-Einstein Condensation", "Dynamics of two colliding Bose-Einstein condensates in an elongated\n  magneto-static trap", "Analysis of Vocal Disorders in a Feature Space", "Braggoriton--Excitation in Photonic Crystal Infiltrated with Polarizable\n  Medium", "Identification of Absorption Features in an Extrasolar Planet Atmosphere", "LNRF-velocity hump-induced oscillations of a Keplerian disc orbiting\n  near-extreme Kerr black hole: A possible explanation of high-frequency QPOs\n  in GRS 1915+105", "Enhancement and suppression of spontaneous emission and light scattering\n  by quantum degeneracy", "Droplet shapes on structured substrates and conformal invariance", "Linkage between Accretion Disks and Blazars", "Global Disk Oscillation Modes in Cataclysmic Variables and Other\n  Newtonian Accretors", "Collisionless collective modes of fermions in magnetic traps", "Very High Energy Gamma Rays from Supernova Remnants and Constraints on\n  the Galactic Interstellar Radiation Field", "Discovery of X-ray emission from the young radio pulsar PSR J1357-6429", "Dynamics of spin correlations in the spin-1/2 isotropic XY chain in a\n  transverse field", "Correlation Functions and Corner Transfer Matrix of the Chiral Potts\n  Model", "SiO maser observations of a wide dust-temperature range sample", "Dirac Fermions on a Two-Dimensional Lattice and the Intermediate\n  Metallic Phase", "Adding Environmental Gas Physics to the Semi-Analytic Method for Galaxy\n  Formation: Gravitational Heating", "Negative differential resistance in nanotube devices", "Self-Consistent Calculation of Total Energies of the Electron Gas Using\n  Many-Body Perturbation Theory", "Collective Modes in Strongly Coupled Elecronic Bilayer Liquids", "The dynamics of Jupiter and Saturn in the gaseous proto-planetary disk", "Elastic Response of Rough Surfaces in Partial Contact", "From favorable atomic configurations to supershell structures: a new\n  interpretation of conductance histograms", "Cool Stars in Hot Places", "The Boundary Conditions of the Heliosphere: Photoionization Models\n  Constrained by Interstellar and In Situ Data", "Decay of metastable phase on heterogeneous centers with continuous\n  activity", "Pinning of quantized vortices in helium drop by dopant atoms and\n  molecules", "Extragalactic Radio Sources and the WMAP Cold Spot", "Coherent dipolar correlations in the ground-state of Kagome frustrated\n  antiferromagnets", "GRB 061121: Broadband spectral evolution through the prompt and\n  afterglow phases of a bright burst", "Outstanding Issues in Our Understanding of L, T, and Y Dwarfs", "Double Neutron Stars: Evidence For Two Different Neutron-Star Formation\n  Mechanisms", "Analysis of Dislocation Mechanism for Melting of Elements", "He-4 spectrum shift caused by He-3 admixture", "GLAST and Dark Matter Substructure in the Milky Way", "How to mode-lock an atom laser", "Gauge Invariant Bosonization of Quantum Hall Systems and Skyrmions :\n  Kinematics", "An integral field spectroscopic survey for high redshift damped\n  Lyman-alpha galaxies", "Damped Bogoliubov excitations of a condensate interacting with a static\n  thermal cloud", "How to measure the Bogoliubov quasiparticle amplitudes in a trapped\n  condensate", "The Araucaria Project. The Distance to the Local Group Galaxy WLM from\n  Cepheid Variables discovered in a Wide-Field Imaging Survey", "Finite-size-scaling analyses of the chiral order in the\n  Josephson-junction ladder with half a flux quantum per plaquette", "Local dark energy: HST evidence from the expansion flow around Cen A/M83\n  galaxy group", "On the detectability of non-trivial topologies", "Magnetic fields in protoplanetary disks", "A case of mistaken identity? GRB 060912A and the nature of the long --\n  short GRB divide", "Bond-Ordering Model for the Glass Transition", "Spin-Orbit Coupling in the ab initio Pseudopotential Framework", "Cosmogenic neutrinos as a probe of the transition from Galactic to\n  extragalactic cosmic rays", "Can a frustrated spin-cluster model describe the low-temperature physics\n  of NaV_2O_5 ?", "Sandpiles and absorbing-state phase transitions: recent results and open\n  problems", "Gemini Mid-IR Polarimetry of NGC1068: Polarized Structures Around the\n  Nucleus", "On the stratified dust distribution of the GG Tau circumbinary ring", "Iron Line Profiles from Relativistic Thick Accretion Disk", "Parametric Simultons in Nonlinear Lattices", "Quantum Dot and Hole Formation in Sputter Erosion", "Exploring the Variable Sky with the Sloan Digital Sky Survey", "Reconstructing the Intrinsic Triaxial Shape of the Virgo Cluster", "Correlated modulation between the redshifted Fe K alpha line and the\n  continuum emission in NGC 3783", "Quantum Phase Transitions and Vortex Dynamics in Superconducting\n  Networks", "Simulating CCD images of elliptical galaxies", "Nonlinear Evolution of Baryon Acoustic Oscillations", "Revisiting He-like X-ray Emission Line Plasma Diagnostics", "Evolution of the Spin Gap Upon Doping a 2-Leg Ladder", "Creep of superconducting vortices in the limit of vanishing temperature:\n  A fingerprint of off-equilibrium dynamics", "Redshifts of the Long Gamma-Ray Bursts", "An International Ultraviolet Explorer Archival Study of Dwarf Novae in\n  Outburst", "Aharonov-Bohm spectral features and coherence lengths in carbon\n  nanotubes", "Compact starburst in the central regions of Seyfert galaxies", "Temperature dependent changes of the Mn 3d and 4p bands near T$_c$ in\n  Colossal Magnetoresistance systems: a XANES study of La$_{1-x}$Ca$_x$MnO$_3$", "Generation and evolution of vortex-antivortex pairs in Bose-Einstein\n  condensates", "OPserver: interactive online-computations of opacities and radiative\n  accelerations", "Wealth condensation in a simple model of economy", "Bose-Einstein Condensates in Optical Lattices: Spontaneous Emission in\n  the Presence of Photonic Band Gaps", "Short wavelength spectrum and Hamiltonian stability of vortex rings", "Exciton-exciton interaction in quantum wells. Optical properties and\n  energy and spin relaxation", "Lattice models and Landau theory for type II incommensurate crystals", "Staggered magnetization, critical behavior and weak ferromagnetic\n  propert ies of LaMnO$_3$ by muon spin rotation", "Fragile-strong transitions and polyamorphism in glass former fluids", "Generalized sqrt(epsilon)-law. The role of unphysical source terms in\n  resonance line polarization transfer and its importance as an additional test\n  of NLTE radiative transfer codes", "The VLT-FLAMES survey of massive stars: Wind properties and evolution of\n  hot massive stars in the LMC", "A class of N-body problems with nearest- and next-to-nearest neighbour\n  interactions", "The Schrodinger Cat Family in Attractive Bose Gases and Their\n  Interference", "Are constant loop widths an artifact of the background and the spatial\n  resolution?", "The Sloan Digital Sky Survey Quasar Catalog IV. Fifth Data Release", "IR observations of MS 1054-03: Star Formation and its Evolution in Rich\n  Galaxy Clusters", "What can emission lines tell us?", "Compaction of a granular material under cyclic shear", "CPA density of states and conductivity in a double-exchange system\n  containing impurities", "Correlation of macroscopic instability and Lyapunov times in the general\n  three-body problem", "Gas-grain chemistry in cold interstellar cloud cores with a microscopic\n  Monte Carlo approach to surface chemistry", "Two-Fluid Hydrodynamics in Trapped Bose Gases and in Superfluid Helium", "Optimizing future imaging survey of galaxies to confront dark energy and\n  modified gravity models", "High Pressure Insulator-Metal Transition in Molecular Fluid Oxygen", "Hedged Monte-Carlo: low variance derivative pricing with objective\n  probabilities", "Radio Emission from the Intermediate-mass Black Hole in the Globular\n  Cluster G1", "The Galactic Center", "Strong compensation of the quantum fluctuation corrections in clean\n  superconductor", "Decrumpling membranes by quantum effects", "Supernova Polarization and the Type IIn Classification", "Near-IR Spectra of Red Supergiants and Giants. I- Models with Solar and\n  with Mixing-Induced Surface Abundance Ratios", "Quantum corrections to the ground state energy of a trapped\n  Bose-Einstein condensate: A diffusion Monte Carlo calculation", "Differentially rotating force-free magnetosphere of an aligned rotator:\n  analytical solutions in split-monopole approximation", "Structures in the Universe and Origin of Galaxies", "Spitzer spectral line mapping of supernova remnants: I. Basic data and\n  principal component analysis", "Radio Lobes of Pictor A: an X-ray spatially resolved Study", "Comment on \"The Transition Temperature of the Dilute Interacting Bose\n  Gas\" and on \"Transition Temperature of a Uniform Bose Gas\"", "Dependence of the physical properties of\n  $Nd_{0.5}Ca_{0.5}MnO_{3+\\delta}$ on the oxydation state of $Mn$", "The Expanding Photosphere Method: Progress and Problems", "The doping dependence of T* - what is the real high-Tc phase diagram?", "Effect of the Orbital Level Difference in Doped Spin-1 Chains", "Now you see it, now you don't - the circumstellar disk in the GRO\n  J1008--57 system", "Quantum group invariant, nonextensive quantum statistical mechanics", "Observation of Anti-correlation between Scintillation and Ionization for\n  MeV Gamma-Rays in Liquid Xenon", "Rotational spectra of weakly interacting Bose-Einstein condensates", "Swift/XRT observes the fifth outburst of the periodic Supergiant Fast\n  X-ray Transient IGR J11215-5952", "Maximum Entropy for Gravitational Wave Data Analysis: Inferring the\n  Physical Parameters of Core-Collapse Supernovae", "Compressibility crossover and quantum opening of a gap for two\n  dimensional disordered clusters with Coulomb repulsion", "Advantages and Disadvantages of Layer Growth Model in Which Particles\n  Maximize Number of Lateral Bonds", "Coulomb gap in a model with finite charge transfer energy", "Multiphase segregation and metal-insulator transition in single crystal\n  La(5/8-y)Pr(y)Ca(3/8)MnO3", "A Spitzer census of the IC 348 nebula", "Phase separation in La$_{0.5}$Ca$_{0.5}$MnO$_3$ doped with 1% $^{119}$Sn\n  detected by M\\\"ossbauer spectroscopy", "PAH emission and star formation in the host of the z~2.56 Cloverleaf QSO", "Excited stationary states of trapped Bose-Einstein condensates", "9.7 micrometer Silicate Absorption in a Damped Lyman-alpha Absorber at\n  z=0.52", "Quantum Critical Dynamics of the Skyrmion Lattice", "Selection effects shaping the Gamma Ray Burst redshift distributions", "Systems with superabsorbing states", "Planets around active stars", "Magnetic properties of the Hubbard model on three-dimensional lattices:\n  fluctuation-exchange and two-particle self-consistent studies", "The polaron confined in one dimension", "Dynamical quenching and annealing in self-organization multiagent models", "Snake orbits and related magnetic edge states", "Modes of counterion density-fluctuations and counterion-mediated\n  attractions between like-charged fluid membranes", "Quantum carpet interferometry for trapped atomic Bose-Einstein\n  condensates", "Distribution of the molecular absorption in front of the quasar\n  B0218+357", "The Exact Solution of 1-D SU(n) Hubbard model", "Deviations from linear theory for fluctuations below the supercritical\n  primary bifurcation to electroconvection", "Cosmological constraints combining H(z), CMB shift and SNIa\n  observational data", "Calibration of the GLAST Burst Monitor detectors", "Nucleation phenomena in a nonuniform atomic fluid in the electrical\n  field", "Transition-metal interactions in aluminum-rich intermetallics", "Intrinsic finite-size effects in the two-dimensional XY model with\n  irrational frustration", "Ultrafast Coulomb-induced dynamics of 2D magnetoexcitons", "Giant Planet Migration in Viscous Power-Law Discs", "Constraining the Dark Energy Equation of State with Cosmic Voids", "Absolute measurement of the nitrogen fluorescence yield in air between\n  300 and 430 nm", "Force-distance studies with piezoelectric tuning forks below 4.2 K", "High Energy Variability Of Synchrotron-Self Compton Emitting Sources:\n  Why One Zone Models Do Not Work And How We Can Fix It", "Infrared High-Resolution Spectroscopy of Post-AGB Circumstellar Disks.\n  I. HR 4049 - The Winnowing Flow Observed?", "Field Dependent Specific-Heat of Rare Earth Manganites", "GRB blastwaves through wind-shaped circumburst media", "IRAS 18317-0757: A Cluster of Embedded Massive Stars and Protostars", "Did time begin? Will time end?", "A critical review of techniques for Term Structure analysis", "Impact of dimensionless numbers on the efficiency of MRI-induced\n  turbulent transport", "Physics of Fashion Fluctuations", "Spectral analysis of Swift long GRBs with known redshift", "Cosmic M\\'enage \\`a Trois: The Origin of Satellite Galaxies On Extreme\n  Orbits", "Many-body Correlation Effects in the Ultrafast Nonlinear Optical\n  Response of Confined Fermi Seas", "Cosmic Ray Origin and Propagation Model", "Eclipsing light curves for accretion flows around a rotating black hole\n  and atmospheric effects of the companion star", "Divergence-free WKB method", "Wide Field Surveys and Astronomical Discovery Space", "Asteroseismic Signatures of Stellar Magnetic Activity Cycles", "Galaxy morphologies and environment in the Abell 901/902 supercluster\n  from COMBO-17", "Swelling-collapse transition of self-attracting walks", "Phase Diagram of a Classical Fluid in a Quenched Random Potential", "Nonequilibrium dynamics of random field Ising spin chains: exact results\n  via real space RG", "Ab initio calculations of response properties including electron-hole\n  interaction", "Analytic verification of the droplet picture in the two-dimensional\n  Ising model", "Stability Properties of Strongly Magnetized Spine Sheath Relativistic\n  Jets", "Search for Very High Energy Emission from Gamma-Ray Bursts using Milagro", "Band-structure trend in hole-doped cuprates and correlation with Tcmax", "A very massive runaway star from Cygnus OB2", "Interactions and star formation activity in Wolf-Rayet galaxies", "Local magnetism of isolated Mo atoms at substitutional and interstitial\n  sites in Yb metal : Experiment and Theory", "Redefining the Missing Satellites Problem", "On the Origin of Asymmetries in Bilateral Supernova Remnants", "Formation of Directed Beams from Atom Lasers", "Stability of Attractive Bose-Einstein Condensates in a Periodic\n  Potential", "A discriminating probe of gravity at cosmological scales", "Monte Carlo Study of Ferromagnetism in (III,Mn)V Semiconductors", "Elementary excitation families and their frequency ordering in\n  cylindrically symmetric Bose-Einstein condensates", "The effect of strain on the adsorption of CO on Pd(100)", "Millimeter and Radio Observations of z~6 Quasars", "Magneto-optical control of bright atomic solitons", "Modelling an Imperfect Market", "Temporally disordered Ising models", "Nucleation of bended vortices in Bose-Einstein condensates in elongated\n  traps", "Features of Hopping Integral and Unconventional Orbital Modes for\n  Quantum Skyrmions in Heisenberg Ferromagnet", "Onset of sliding friction in incommensurate systems", "Late stages of stellar evolution and their impact on spectrophotometric\n  properties of galaxies", "Observations towards early-type stars in the ESO-POP survey: II --\n  searches for intermediate and high velocity clouds", "Single and Paired Point Defects in a 2D Wigner Crystal", "Lattice model for kinetics and grain size distribution in\n  crystallization", "Neglecting the porosity of hot-star winds can lead to underestimating\n  mass-loss rates", "Absorption in periodic layered structures", "Dark Matter Searche with GLAST", "Study on Correlations between the Twin Kilohertz Quasi-periodic\n  Oscillations in Low-mass X-ray Binaries", "Algebra versus analysis in statistical mechanics and quantum field\n  theory", "Timing and Lensing of the Colliding Bullet Clusters: barely enough time\n  and gravity to accelerate the bullet", "Two Stages in the evolution of binary alkali Bose-Einstein condensate\n  mixtures towards phase segregation", "A scalable solid-state quantum computer based on quantum dot pillar\n  structures", "A new class of integrable diffusion-reaction processes", "Water vapor and silicon monoxide maser observations in the\n  protoplanetary nebula OH 231.8+4", "Vertical dynamics of disk galaxies in MOND", "FIRST-based survey of Compact Steep Spectrum sources, V.\n  Milliarcsecond-scale morphology of CSS objects", "Finite temperature hydrodynamic modes of trapped quantum gases", "Screening Breakdown on the Route toward the Metal-Insulator Transition\n  in Modulation Doped Si/SiGe Quantum Wells", "Power laws and collapsing dynamics of a trapped Bose-Einstein condensate\n  with attractive interactions", "Mass and Temperature of the TWA 7 Debris Disk", "Harmonics generation in electron-ion collisions in a short laser pulse", "Kinetics of spin coherence of electrons in an undoped semiconductor\n  quantum well", "Proper motion L and T dwarf candidate members of the Pleiades", "A multifractal random walk", "Modeling the three-point correlation function", "The HARPS search for southern extra-solar planets. X. A m sin i = 11\n  Mearth planet around the nearby spotted M dwarf GJ 674", "Correlation gap in the optical spectra of the two-dimensional organic\n  metal (BEDT-TTF)_4[Ni(dto)_2]", "Compton thick AGN in the Suzaku era", "Dynamics and Scaling of Noise-Induced Domain Growth", "An Inner Hole in the Disk around TW Hydrae Resolved in 7 Millimeter Dust\n  Emission", "Critical light scattering in liquids", "Overcritical Rotation of a Trapped Bose-Einstein Condensate", "Nonlinear acoustic and microwave absorption in disordered semiconductors", "Isotropic Conductivity of Two-Dimensional Three-Component Symmetric\n  Composites", "Freezing of dynamical exponents in low dimensional random media", "Abundances in intermediate-mass AGB stars undergoing third dredge-up and\n  hot-bottom burning", "X-ray and Sunyaev-Zel'dovich scaling relations in galaxy clusters", "Quantum Phase Interference for Quantum Tunneling in Spin Systems", "The bimodality of type Ia Supernovae", "SW Sextantis stars: the dominant population of CVs with orbital periods\n  between 3-4 hours", "A model of a pumped continuous atom laser", "High Precision CTE-Measurement of SiC-100 for Cryogenic Space-Telescopes", "Molecular dynamics simulation of the fragile glass former\n  ortho-terphenyl: a flexible molecule model. II. Collective dynamics", "Gaseous Inner Disks", "Photometry of the Globular Cluster NGC 5466: Red Giants and Blue\n  Stragglers", "Laterally coupled few-electron quantum dots", "Thermodynamics of the Spin-1/2 Antiferromagnetic Uniform Heisenberg\n  Chain", "Flavor Composition and Energy Spectrum of Astrophysical Neutrinos", "Direct Observation of the Quantum Energy Gap in S = 1/2 Tetragonal\n  Cuprate Antiferromagnets", "Auger decay, Spin-exchange, and their connection to Bose-Einstein\n  condensation of excitons in Cu_2O", "Interactions of several replicas in the random field Ising model", "The phase diagram of the lattice Calogero-Sutherland model", "The XMM-SSC survey of hard-spectrum XMM-Newton sources 1: optically\n  bright sources", "Specific heat of (Y,Lu)Ni2B2C in the mixed state", "Third-order cosmological perturbations of zero-pressure multi-component\n  fluids: Pure general relativistic nonlinear effects", "Numerical study of persistence in systems with absorbing states", "Old Main-Sequence Turnoff Photometry in the Small Magellanic Cloud. I.\n  Constraints on the Star Formation History in Different Fields", "Prompt Emission of High Energy Photons from Gamma Ray Bursts", "On the Possibility of Abnormally Intense Radiation Due to the Rotation\n  of Electron Around a Dielectric Sphere", "Compton Scattering of Fe K alpha Lines in Magnetic Cataclysmic Variables", "DIRBE Minus 2MASS: Confirming the CIRB in 40 New Regions at 2.2 and 3.5\n  Microns", "Renormalization of pinned elastic systems: how does it work beyond one\n  loop ?", "An Exact Monte Carlo Method for Continuum Fermion Systems", "The Formation of Globular Cluster Systems in Massive Elliptical\n  Galaxies: Globular Cluster Multimodality from Radial Variation of Stellar\n  Populations", "Precise Timing of the X-ray Pulsar 1E 1207.4-5209: A Steady Neutron Star\n  Weakly Magnetized at Birth", "Diabolical Points in Molecular Magnets with a Four-Fold Easy Axis", "Theory of Ferromagnetism in Diluted Magnetic Semiconductors", "Thermodynamics of the spin-flop transition in a quantum XYZ chain", "Modeling Accretion Disk X-ray Continuum of Black Hole Candidates", "A User-Friendly Code to Diagnose Chromospheric Plasmas", "Time-reversal symmetry in nonlinear optics", "Multiple energy x-ray holography: the polarization effect", "Non-linear Transport in Quantum-Hall Smectics", "Metal and molecule cooling in simulations of structure formation", "Intermittent implosion and pattern formation of trapped Bose-Einstein\n  condensates with attractive interaction", "The HARPS search for southern extra-solar planets. IX. Exoplanets\n  orbiting HD 100777, HD 190647, and HD 221287", "Demographics of Transition Objects", "Effective Hamiltonians and dilution effects in kagome and related\n  antiferromagnets", "Atomic scale engines: Cars and wheels", "Turbulent Mixing in the Surface Layers of Accreting Neutron Stars", "Possible Triplet Electron Pairing and an Anisotropic Spin Susceptibility\n  in Organic Superconductors (TMTSF)_2 X", "A conformal field theory description of the paired and parafermionic\n  states in the quantum Hall effect", "CalFUSE v3: A Data-Reduction Pipeline for the Far Ultraviolet\n  Spectroscopic Explorer", "Evidence for a Massive Protocluster in S255N", "Two-magnon Raman scattering in spin-ladder geometries and the ratio of\n  rung and leg exchange constants", "Level and Eigenfunction Statistics in Billiards with Surface Scattering", "Comments on ``Are Swift Gamma-Ray Bursts consistent with the Ghirlanda\n  relation?\", by Campana et al.(astro--ph/0703676)", "Universal Substructure Distributions in LCDM halos: Can we find a Fossil\n  Group?", "Kinematic Decoupling of Globular Clusters with Extended\n  Horizontal-Branch", "Near-Infrared and X-ray Observations of the Enigmatic G70.7+1.2", "Stabilizing an Attractive Bose-Einstein Condensate by Driving a Surface\n  Collective Mode", "Edge Singularity for the Optically Induced Kondo Effect in a Quantum Dot", "Effective Lorentz Force due to Small-angle Impurity Scattering:\n  Magnetotransport in High-Tc Superconductors", "Oxygen-rich droplets and the enrichment of the ISM", "Can GLAST detect gamma-rays from the extended radio features of radio\n  galaxies?", "Spectral Analysis of the Chandra Comet Survey", "Dark matter caustics and the enhancement of self-annihilation flux", "Variational wave functions of a vortex in cyclotron motion", "Watching dark solitons decay into vortex rings in a Bose-Einstein\n  condensate", "Damping of condensate collective modes due to equilibration with the\n  non-condensate", "Visible spectroscopic and photometric survey of Jupiter Trojans: final\n  results on dynamical families", "On the Structure and Properties of Differentially Rotating Main-Sequence\n  Stars in the 1-2 M_sun Range", "Formation and Collisional Evolution of Kuiper Belt Objects", "Enhanced Spin Polarization of Conduction Electrons in Ni, explained by\n  comparison with Cu", "Numerical analysis of the magnetic-field-tuned superconductor-insulator\n  transition in two dimensions", "Power Spectra to 1% Accuracy between Dynamical Dark Energy Cosmologies", "Muffin Tin Orbitals of Arbitrary Order", "Off equilibrium magnetic properties in a model for vortices in\n  superconductors", "The height dependence of temperature - velocity correlation in the solar\n  photosphere", "The 3D soft X-ray cluster-AGN cross-correlation function in the ROSAT\n  NEP survey", "Vertical Melting of a Stack of Membranes", "Spin-Peierls instability in the spin-1/2 transverse XX chain with\n  Dzyaloshinskii-Moriya interaction", "Skyrmions in a ferromagnetic Bose-Einstein condensate", "Far-infrared excitations in a quantum antidot at finite magnetic fields", "Phase Diagram Structure of the Harper Map", "The young, wide and very low mass visual binary LOri167", "Dynamics of aeolian sand ripples", "Terrestrial and Habitable Planet Formation in Binary and Multi-star\n  Systems", "Magnetization processes in quantum spin chains with regularly\n  alternating intersite interactions", "Substructures in WINGS clusters", "Stable Vortex Configurations in a Cylinder", "Effective temperature vs line-depth ratio for ELODIE spectra. Gravity\n  and rotational velocity effects", "Shift in the velocity of a front due to a cut-off", "Quantum Tunneling of Magnetization in Molecular Complexes with Large\n  Spins. Effect of the Environment", "A Catalog of Star Cluster Candidates in M33", "Rotation Measures of Extragalactic Sources Behind the Southern Galactic\n  Plane: New Insights into the Large-Scale Magnetic Field of the Inner Milky\n  Way", "Analytical Results for Trapped Weakly Interacting Bosons in Two\n  Dimensions", "Two-dimensional dilute Bose gas in the normal phase", "Similarity transformation in one-dimensional reaction-diffusion systems;\n  voting model as an example", "Bose condensates at high angular momenta", "INTEGRAL and Multiwavelength Observations of the Blazar Mrk 421 during\n  an Active Phase", "Analysis of the Velocity Field of F and G Dwarfs in the Solar\n  Neighborhood as a Function of Age", "A Dynamical Thermostat Approach To Financial Asset Price Dynamics", "The Spitzer c2d Survey of Large, Nearby, Interstellar Clouds VIII.\n  Serpens Observed with MIPS", "Planck Length and Cosmology", "Radiation from Kinetic Poynting Flux Acceleration", "The IDV source J1128+5925, a new candidate for annual modulation?", "Masers and star formation", "High resolution infrared absorption spectra, crystal field, and\n  relaxation processes in CsCdBr_3:Pr^3+", "AKARI Detection of the Infrared-Bright Supernova Remnant B0104-72.3 in\n  the Small Magellanic Cloud", "The Differential Rotation of Kappa1 Ceti as Observed by MOST", "Spin-orbit and exchange interaction in surface quantum wells on gapless\n  semimagnetic semiconductor HgMnTe", "Quasiperiodic time dependent current in driven superlattices: distorted\n  Poincare maps and strange attractors", "What made GRBs 060505 and 060614?", "The Extragalactic Gamma Ray Background", "The Source of Turbulence in Astrophysical Disks: An Ill-posed Problem.", "Cationic ordering control of magnetization in Sr2FeMoO6 double\n  perovskite", "Testing turbulence model at metric scales with mid-infrared VISIR images\n  at the VLT", "Nuclear Spin-Ordering Due to Correlated Atomic Motion in bcc $^3$He", "Enhanced activity of massive black holes by stellar capture assisted by\n  a self-gravitating accretion disc", "Star Formation in Galaxies with Large Lower Surface Brightness Disks", "Short, Medium and Long Range Spatial Correlations in Simple Glasses", "The luminous infrared composite Seyfert 2 galaxy NGC 7679 through the [O\n  III] 5007 emission line", "Neutrino-cooled accretion and GRB variability", "Sunyaev-Zel'dovich profiles and scaling relations: modelling effects and\n  observational biases", "Good News for MOS, MXU & Co. - The New Spectroscopic Pipeline for the\n  FORSes", "Nature of traps responsible for failure of MOS devices", "A Waveguide for Bose-Einstein Condensates", "Comparison of structural transformations and superconductivity in\n  compressed Sulfur and Selenium", "3.8-Micron Photometry During the Secondary Eclipse of the Extrasolar\n  Planet HD 209458b", "Ellipsoidal Oscillations Induced by Substellar Companions: A Prospect\n  for the Kepler Mission", "Multi-mode description of an interacting Bose-Einstein condensate", "A real-space, rela-time method for the dielectric function", "Galaxy evolution in the infra-red: comparison of a hierarchical galaxy\n  formation model with SPITZER data", "The interacting system of electrons, positrons and photons in high\n  external electric and arbitrary magnetic fields", "3-D Simulations of Ergospheric Disk Driven Poynting Jets", "Percolation, Bose-Einstein Condensation, and String Proliferation", "A survey of debris trails from short-period comets", "Random-mass Dirac fermions in an imaginary vector potential:\n  Delocalization transition and localization length", "Theory of Diluted Magnetic Semiconductor Ferromagnetism", "Are extrasolar oceans common throughout the Galaxy?", "Compton X-ray and Gamma-ray Emission from Extended Radio Galaxies", "Unambiguous determination of the g-factor for holes in bismuth at high\n  B/T", "Frequencies and Damping rates of a 2D Deformed Trapped Bose gas above\n  the Critical Temperature", "Detecting and Characterizing Planetary Systems with Transit Timing", "Sensitivity of low degree oscillations to the change in solar abundances", "Theory for two-photon photoemission: transport and temperature effects", "Trigonometric parallaxes of high velocity halo white dwarf candidates", "Evolution of reference networks with aging", "SkyMapper and the Southern Sky Survey - a resource for the southern sky", "Spin-Peierls instability in a quantum spin chain with\n  Dzyaloshinskii-Moriya interaction", "A Near-Infrared Study of the Highly-Obscured Active Star-Forming Region\n  W51B", "Higher-Order Angular Galaxy Correlations in the SDSS: Redshift and Color\n  Dependence of non-Linear Bias", "2MASS Reveals a Large Intrinsic Fraction of BALQSOs", "Dissipationless Spin Transport in Thin Film Ferromagnets", "Detection of a 1258 Hz high-amplitude kilohertz quasi-periodic\n  oscillation in the ultra-compact X-ray binary 1A 1246-588", "Spatially modulated magnetic structures in thin films", "Decoherence and long-lived Schroedinger cats in BEC", "Bose-Einstein condensation of excitons in Cu$_2$O", "Sum Rule Approach to Collective Oscillations of Boson-Fermion Mixed\n  Condensate of Alkali Atoms", "Observation of Nanometer-Scale Rolling Motion Mediated by Commensurate\n  Contact", "Comptonization and the Spectra of Accretion-Powered X-Ray Pulsars", "Attractive Boson and the Gas-Liquid Condensation", "Pin-Hole Water Flow from Cylindrical Bottles", "Incommensurate Spin-Peierls Phases in the One-Dimensional Quantum\n  Isotropic XY Model", "Multi-epoch VLBA observations of 3C 66A", "Many Body Diffusion and Interacting Electrons in a Harmonic Confinement", "Supernova Remnants and GLAST", "The Kilodegree Extremely Little Telescope (KELT): A Small Robotic\n  Telescope for Large-Area Synoptic Surveys", "LEAVITT: A MIDEX-class Mission for Finding & Characterizing 10,000\n  Transiting Planets in the Solar Neighborhood", "A Statistical Mechanics Approach to the Inherent States of Granular\n  Media", "Shape deformations and angular momentum transfer in trapped\n  Bose-Einstein condensates", "The Blue Straggler Population of the Globular Cluster M5", "Nonlinear force-free coronal magnetic field extrapolation scheme based\n  on the direct boundary integral formulation", "Stabilization of ratchet dynamics by weak periodic signals", "Iterative algorithm versus analytic solutions of the parametrically\n  driven dissipative quantum harmonic oscillator", "Macroscopic quantum tunneling of the Bose-Einstein condensate trapped in\n  cylindrically symmetric potential", "Crossover behavior in He3 and Xe near their liquid-vapor critical point", "Light Curves of Dwarf Plutonian Planets and other Large Kuiper Belt\n  Objects: Their Rotations, Phase Functions and Absolute Magnitudes", "High-field AFMR in single-crystalline La_{0.95}Sr_{0.05}MnO_3:\n  Experimental evidence for the existence of a canted magnetic structure", "REM near-IR and optical multiband observations of PKS2155-304 in 2005", "Structure of Growing Networks: Exact Solution of the Barabasi--Albert's\n  Model", "A.model of cation ordering in A(B'_xB''_1-x)O_3 relaxors", "Dust Formation and He II 4686 emission in the Dense Shell of the\n  Peculiar Type Ib Supernova 2006jc", "A multi-transition molecular line study of candidate massive young\n  stellar objects associated with methanol masers", "SDSS J102146.44+234926.3: New WZ Sge-type dwarf nova", "Colour pairs for constraining the age and metallicity of stellar\n  populations", "Follow-up observations of pulsating subdwarf B stars: Multisite\n  campaigns on PG 1618+563B and PG 0048+091", "Higher Order Effects in the Dielectric Constant of Percolative\n  Metal-Insulator Systems above the Critical Point", "Interaction-induced Bose Metal in 2D", "Current Induced Magnetization Switching in Small Domains of Different\n  Anisotropies", "Microscopic models of traveling wave equations", "Moment of Inertia and Quadrupole Response Function of a Trapped\n  Superfluid", "The obscured X-ray source population in the HELLAS2XMM survey: the\n  Spitzer view", "Relaxation in kinetic models on alternating linear chains", "VLBI observations of nineteen GHz-Peaked-Spectrum radio sources at 1.6\n  GHz", "The Millennium Galaxy Catalogue: the B-band attenuation of bulge and\n  disc light and the implied cosmic dust and stellar mass densities", "Structure and Magnetism of well-defined cobalt nanoparticles embedded in\n  a niobium matrix", "$uvby-H_\\beta$ CCD photometry and membership segregation of the open\n  cluster NGC2682 (M67)", "Spheroidal and torsional modes of quasistatic shear oscillations in the\n  solid globe models of nuclear physics and pulsar astrophysics", "Excitations of the field-induced soliton lattice in CuGeO3", "SIM PlanetQuest: The Most Promising Near-Term Technique to Detect, Find\n  Masses, and Determine Three-Dimensional Orbits of Nearby Habitable Planets", "Effective Charge and Spin Hamiltonian for the Quarter-Filled Ladder\n  Compound $\\alpha'$-NaV$_2$O$_5$", "Double Exchange in Electron Doped Ca1-xYxMnO3 Manganites", "Searches for Ultra-Compact Dwarf Galaxies in Galaxy Groups", "Spin correlations in the two-leg antiferromagnetic ladder in a magnetic\n  field", "The Spectral Index Distribution of EGRET Blazars: Prospects for GLAST", "First Constraints on Source Counts at 350 Microns", "Constraints on gamma-ray burst and supernova progenitors through\n  circumstellar absorption lines. (II): Post-LBV Wolf-Rayet stars", "The core binary fractions of star clusters from realistic simulations", "Twin wall of cubic-tetragonal ferroelastics", "Delocalization of two-particle ring near the Fermi level of 2d Anderson\n  model", "Incorporation of Density Matrix Wavefunctions in Monte Carlo\n  Simulations: Application to the Frustrated Heisenberg Model", "The Use of Weighting in Periodicity Searches in All-Sky Monitor Data:\n  Applications to the GLAST LAT", "GEMS: Galaxy fitting catalogues and testing parametric galaxy fitting\n  codes", "Binary Capture Rates for Massive Protostars", "ab initio modeling of open systems: charge transfer, electron\n  conduction, and molecular switching of a C_{60} device", "Newtonian limit of scalar-tensor theories and galactic dynamics:\n  isolated and interacting galaxies", "Finite temperature dynamic structure function of the free Bose gas", "Boundary Conditions in Diffusional Growth and Sedimentation", "Surface states in nearly modulated systems", "Modelling fluctuations of financial time series: from cascade process to\n  stochastic volatility model", "Ages for illustrative field stars using gyrochronology: viability,\n  limitations and errors", "Neutrino Astronomy with High Spatial Resolution is Already Existing", "Pseudogap in the Optical Spectra of UPd_2Al_3", "Probing Bose-Einstein Condensation of Excitons with Electromagnetic\n  Radiation", "Third Order Renormalization Group applied to the attractive\n  one-dimensional Fermi Gas", "c2d Spitzer IRS Spectra of Disks around T Tauri Stars. III. [Ne II], [Fe\n  I], and H_2 gas-phase lines", "Spectral Analysis of GRBs Measured by RHESSI", "A Photoevaporating Rotating Disk in the Cepheus A HW2 Star Cluster", "Tractable non-local correlation density functionals for flat surfaces\n  and slabs", "Outflow and Infall in a Sample of Massive Star Forming Regions", "Spectroscopy of Nine Cataclysmic Variable Stars", "Multi-Color Photometry of the Galactic Globular Cluster M75 = NGC 6864.\n  A New Sensitive Metallicity Indicator and the Position of the Horizontal\n  Branch in UV", "The Onset of Phase Transitions in Condensed Matter and Relativistic QFT", "Normal Stress Distribution of Rough Surfaces in Contact", "Externally-polluted white dwarfs with dust disks", "The Angular Separation of the Components of the Cepheid AW Per", "GRO J1655-40: from ASCA and XMM-Newton Observations", "The old open clusters Berkeley 32 and King 11", "The Luminosity Distribution of Globular Clusters in Dwarf Galaxies", "Stirring the Embers: High Sensitivity VLBI Observations of GRB030329", "Why are accreting T Tauri stars observed to be less luminous in X-rays\n  than non-accretors?", "Evidence for a planetary companion around a nearby young star", "Gravity-induced Wannier-Stark ladder in an optical lattice", "Cooperative Electromagnetic Effects", "Recovering galaxy star formation and metallicity histories from spectra\n  using VESPA", "Extended solar emission - an analysis of the EGRET data", "Image charges revisited: a closed form solution", "Influence of gauge fluctuations on fermion pairing order parameter", "4U 0115+63 from RXTE and INTEGRAL Data: Pulse Profile and Cyclotron Line\n  Energy", "Finding (or not) New Gamma-ray Pulsars with GLAST", "The transverse proximity effect in spectral hardness on the line of\n  sight towards HE 2347-4342", "Role of Fermi-level pinning in nanotube Schottky diodes", "Massive skyrmions in quantum Hall ferromagnets", "Satellites of Simulated Galaxies: survival, merging, and their relation\n  to the dark and stellar halos", "Piezoelectricity and Piezomagnetism : Duality in Two-Dimensional\n  Checkerboards", "658 GHz Vibrationally-Excited Water Masers with the Submillimeter Array", "High frequency resonant experiments in Fe$_8$ molecular clusters", "Theory of interlayer tunneling in bi-layer quantum Hall ferromagnets", "The Discovery of a Companion to the Lowest Mass White Dwarf", "Resonant relaxation near a massive black hole: the dependence on\n  eccentricity", "Efficient Total Energy Calculations from Self-Energy Models", "XMMU J174716.1-281048: a \"quasi-persistent\" very faint X-ray transient?", "Comparing schemes of displacement detection and subharmonic generation\n  in nanomachined mechanical resonators", "Ground-based Microlensing Surveys", "Extended envelopes around Galactic Cepheids III. Y Oph and alpha Per\n  from near-infrared interferometry with CHARA/FLUOR", "Fractional vortices in the XY model with $\\pi$ bonds", "The Sigma-D Relation for Planetary Nebulae: Preliminary Analysis", "Six New ZZ Ceti Stars from the SPY and the HQS Surveys", "Elastic response of [111]-tunneling impurities", "The Realm of the First Quasars in the Universe: the X-ray View", "Generalized Thermostatistical Description of Intermittency and\n  Non-extensivity in Turbulence and Financial Markets", "Generalization of k.p theory for periodic perturbations", "A new search for planet transits in NGC 6791", "Near and Mid-IR Photometry of the Pleiades, and a New List of Substellar\n  Candidate Members", "Modelling the clumping-induced polarimetric variability of hot star\n  winds", "Dissipation of Magnetic Flux in Primordial Star Formation: From Run-away\n  Phase to Mass Accretion Phase", "Acoustic radiation in randomly-layered structures", "Linear and nonlinear susceptibilities of a decoherent two-level system", "Weakly Interacting Bose-Einstein Condensates Under Rotation: Mean-field\n  versus Exact Solutions", "A Panchromatic Study of the Globular Cluster NGC 1904. I: The Blue\n  Straggler Population", "Progenitors of Long Gamma-ray Bursts", "Oscillator Strength of Metallic Carbon Nanotubes", "U B V R I Photometry of Stellar Structures throughout the Disk of the\n  Barred Galaxy NGC 3367", "3D photospheric velocity field of a Supergranular cell", "Frequency Dependence of Aging, Rejuvenation and Memory in a disordered\n  ferroelectric", "Carbon Nanotubes Synthesized in Channels of Alpo4-5 Single Crystals :\n  First X-Ray Scattering Investigations", "Superradiant light scattering and grating formation in cold atomic\n  vapours", "What can superconductivity learn from quantized vorticity in He-3\n  superfluids?", "Disorder Induced Transitions in Layered Coulomb Gases and\n  Superconductors", "Thermal properties of ferrimagnetic systems", "INTEGRAL high energy detection of the transient IGR J11321-5311", "Absorption features of high redshift galactic winds"], "train_abstracts": ["Following the observation and analysis of large-scale coronal wave-like\ndisturbances, we discuss the theoretical progress made in the field of global\ncoronal seismology. Using simple mathematical techniques we determine average\nvalues for magnetic field together with a magnetic map of the quiet Sun. The\ninteraction between global coronal waves and coronal loops allows us to study\nloop oscillations in a much wider context, i.e. we connect global and local\ncoronal oscillations.", "We present the most successful infrared cloud monitor for a robotic\ntelescope. This system was originally developed for the MAGNUM 2-m telescope,\nwhich has been achieving unmanned and automated monitoring observation of\nactive galactic nuclei at Haleakala on the Hawaiian island of Maui since 2001.\nUsing a thermal imager and two aspherical mirrors, it at once sees almost the\nwhole sky at a wavelength of $\\lambda\\sim 10\\mu{\\rm m}$. Its outdoor part is\nweather-proof and is totally maintenance-free. The images obtained every one or\ntwo minutes are analysed immediately into several ranks of weather condition,\nfrom which our automated observing system not only decides to open or close the\ndome, but also selects what types of observations should be done. The whole-sky\ndata accumulated over four years show that 50$-$60 % of all nights are\nphotometric, and about 75 % are observable with respect to cloud condition at\nHaleakala. Many copies of this system are now used all over the world such as\nMauna Kea in Hawaii, Atacama in Chile, and Okayama and Kiso in Japan.", "The identification of basaltic asteroids in the asteroid Main Belt and the\ndescription of their surface mineralogy is necessary to understand the\ndiversity in the collection of basaltic meteorites. Basaltic asteroids can be\nidentified from their visible reflectance spectra and are classified as V-type\nin the usual taxonomies. In this work, we report visible spectroscopic\nobservations of two candidate V-type asteroids, (7472) Kumakiri and (10537)\n1991 RY16, located in the outer Main Belt (a > 2.85 UA). These candidate have\nbeen previously identified by Roig and Gil-Hutton (2006, Icarus 183, 411) using\nthe Sloan Digital Sky Survey colors. The spectroscopic observations have been\nobtained at the Calar Alto Observatory, Spain, during observational runs in\nNovember and December 2006. The spectra of these two asteroids show the steep\nslope shortwards of 0.70 microns and the deep absorption feature longwards of\n0.75 microns that are characteristic of V-type asteroids. However, the presence\nof a shallow but conspicuous absorption band around 0.65 microns opens some\nquestions about the actual mineralogy of these two asteroids. Such band has\nnever been observed before in basaltic asteroids with the intensity we detected\nit. We discuss the possibility for this shallow absorption feature to be caused\nby the presence of chromium on the asteroid surface. Our results indicate that,\ntogether with (1459) Magnya, asteroids (7472) Kumakiri and (10537) 1991 RY16\nmay be the only traces of basaltic material found up to now in the outer Main\nBelt.", "We present new X-ray timing and spectral observations of PSR J1930+1852, the\nyoung energetic pulsar at the center of the non-thermal supernova remnant\nG54.1+0.3. Using data obtained with the Rossi X-ray Timing Explorer and Chandra\nX-ray observatories we have derived an updated timing ephemeris of the 136 ms\npulsar spanning 6 years. During this interval, however, the period evolution\nshows significant variability from the best fit constant spin-down rate of\n$\\dot P = 7.5112(6) \\times 10^{-13}$ s s$^{-1}$, suggesting strong timing noise\nand/or glitch activity. The X-ray emission is highly pulsed ($71\\pm5%$\nmodulation) and is characterized by an asymmetric, broad profile ($\\sim 70%$\nduty cycle) which is nearly twice the radio width. The spectrum of the pulsed\nemission is well fitted with an absorbed power law of photon index $\\Gamma =\n1.2\\pm0.2$; this is marginally harder than that of the unpulsed component. The\ntotal 2-10 keV flux of the pulsar is $1.7 \\times 10^{-12}$ erg cm$^{-2}$\ns$^{-1}$. These results confirm PSR J1930+1852 as a typical Crab-like pulsar.", "A system with a metastable phase and a pseudo continuous set of the\nheterogeneous centers is considered. An analytical theory for kinetics of the\nprocess of condensation in such a system is constructed. The free energy of\nformation of the critical embryo is assumed to be known in the capillary\n(macroscopic) approach as well as the solvatation energy of the embryo. The\ntheory is based on the quasistationary approximation for the nucleation rate\nwhich has been justified analytically. An effective iteration procedure is\npresented. The iterations are calculated analytically. The approximate\nuniversal form of the spectrum is established.", "The conventional magnetic induction equation that governs hydromagnetic\ndynamo action is transformed into an equivalent integral equation system. An\nadvantage of this approach is that the computational domain is restricted to\nthe region occupied by the electrically conducting fluid and to its boundary.\nThis integral equation approach is first employed to simulate kinematic dynamos\nexcited by Beltrami-like flows in a finite cylinder. The impact of externally\nadded layers around the cylinder on the onset of dynamo actions is\ninvestigated. Then it is applied to simulate dynamo experiments within\ncylindrical geometry including the von Karman sodium (VKS) experiment and the\nRiga dynamo experiment. A modified version of this approach is utilized to\ninvestigate magnetic induction effects under the influence of externally\napplied magnetic fields which is also important to measure the proximity of a\ngiven dynamo facility to the self-excitation threshold.", "It is proposed that radiation belts similar to the ones in the planetary\nmagnetosphere can exist for a pulsar with a relatively long period and a strong\nmagnetic field. In the belts located in the closed field line region near the\nlight cylinder relativistic pairs are trapped and maintained at a density\nsubstantially higher than the local Goldreich-Julian corotation density. The\ntrapped plasma can be supplied and replenished by either direct injection of\nrelativistic pairs from acceleration of externally-supplied particles in a\ndormant outer gap or in situ ionization of the accreted neutral material in the\ntrapping region. The radiation belts can be disrupted by waves that are excited\nin the region as the result of plasma instabilities or emitted from the surface\ndue to starquakes or stellar oscillations. The disruption can cause an\nintermittent particle precipitation toward the star producing radio bursts. It\nis suggested that such bursts may be seen as rotating radio transients (RRATs).", "We study the spatio-temporal behavior of simple coupled map lattices with\nperiodic boundary conditions. The local dynamics is governed by two maps,\nnamely, the sine circle map and the logistic map respectively. It is found that\neven though the spatial behavior is irregular for the regularly coupled\n(nearest neighbor coupling) system, the spatially synchronized (chaotic\nsynchronization) as well as periodic solution may be obtained by the\nintroduction of three long range couplings at the cost of three nearest\nneighbor couplings.", "We have selected a sample of 88 nearby (z<0.1) galaxy clusters from the\nSDSS-DR4 with redshift information for the cluster members. We have derived\nglobal properties for each cluster, such as their mean recessional velocity,\nvelocity dispersion, and virial radii. Cluster galaxies have been grouped in\ntwo families according to their $u-r$ colours. The total sample consists of\n10865 galaxies. As expected, the highest fraction of galaxies (62%) turned to\nbe early-type (red) ones, being located at smaller distances from the cluster\ncentre and showing lower velocity dispersions than late-type (blue) ones. The\nbrightest cluster galaxies are located in the innermost regions and show the\nsmallest velocity dispersions. Early-type galaxies also show constant velocity\ndispersion profiles inside the virial radius and a mild decline in the\noutermost regions. In contrast, late-type galaxies show always decreasing\nvelocity dispersions profiles. No correlation has been found between the\nfraction of blue galaxies and cluster global properties, such as cluster\nvelocity dispersion and galaxy concentration. In contrast, we found correlation\nbetween the X-ray luminosity and the fraction of blue galaxies. These results\nindicate that early- and late-type galaxies may have had different evolution.\nThus, blue galaxies are located in more anisotropic and radial orbits than\nearly-type ones. Their star formation seems to be independent of the cluster\nglobal properties in low mass clusters, but not for the most massive ones.\nThese observational results suggest that the global environment could be\nimportant for driving the evolution of galaxies in the most massive cluster\n($\\sigma > 800$ km s$^{-1}$). However, the local environment could play a key\nrole in galaxy evolution for low mass clusters.", "Fourier phases contain a vast amount of information about structure in direct\nspace, that most statistical tools never tap into. We address ALMA's ability to\ndetect and recover this information, using the probability distribution\nfunction (PDF) of phase increments, and the related concepts of phase entropy\nand phase structure quantity. We show that ALMA, with its high dynamical range,\nis definitely needed to achieve significant detection of phase structure, and\nthat it will do so even in the presence of a fair amount of atmospheric phase\nnoise. We also show that ALMA should be able to recover the actual \"amount\" of\nphase structure in the noise-free case, if multiple configurations are used.", "We study acoustic propagation in one dimensional water ducts containing many\nair-filled blocks. The acoustic band structures for the periodic arrangements\nof the blocks is calculated, whereas the transmission for various random\nconfigurations of the blocks is computed by the transfer matrix method. It is\nshown that waves at all frequencies become localized even with a small amount\nof randomness. The spatial distribution of the localized energy is\ninvestigated, and is shown not to be trapped near the source, contrary to\nhigher dimensional cases. The results also reveal a distinct collective\nbehaviour for localized waves, a feature useful for distinguishing the\nlocalization from the residual absorption effect.", "The results we presented were biased because of the typing error in the code\ntranscription of the equation (A.12). We will replace by the corrected version\nsoon. The brief of the corrected results can be found at\nhttp://www.physics.cz/research/doc/posters/1181038112_0.pdf", "We study the effect of the kick velocity -- neutron star spin alignment\nobserved in young radio pulsars on the coalescence rate of binary neutron\nstars. The effect is shown to be especially strong for large kick amplitudes\nand tight alignments, reducing the galactic rate of binary neutron star\ncoalescences up to an order of magnitude with respect to the rates calculated\nfor random kicks. The spin-kick correlation also leads to much narrower NS\nspin-orbit misalignments compared to random kicks.", "Propagation of acoustic waves in an one-dimensional water duct containing\nmany air filled blocks is studied by the transfer matrix formalism. Energy\ndistribution and interface vibration of the air blocks are computed. For\nperiodic arrangement band structure and transmission rate are calculated\nanalytically, whereas the Lyapunov exponent and its variance are computed\nnumerically for random situations. A distinct collective behavior for localized\nwaves is found. The results are also compared with optical situations.", "A structural model of a one-component $\\sigma$-phase crystal has been\nconstructed by means of molecular dynamics simulation. The phonon dispersion\ncurves and the vibrational density of states were computed for this model. The\ndependence of the vibrational properties on the thermodynamical parameters was\ninvestigated. The vibrational density of states of the $\\sigma$-phase structure\nis found to be similar to that of a one-component glass with icosahedral local\norder. On the basis of this comparison it is concluded that the $\\sigma$ phase\ncan be considered to be a good crystalline reference structure for this glass.", "The expansion of the Universe is accelerating, as testified by observations\nof supernovae of type Ia as a function of redshift. Explanations are of two\ntypes: modifications of Einstein gravity or new forms of energy, coined dark\nenergy.The accelerated expansion is explained here by a combination of\nDvali-Gabadadze-Porrati (DGP) model gravity and Chaplygin gas dark energy. Both\nmodels are characterized by a length scale L which may be the same. The\ncontinuity equation for the combined model is derived in flat geometry, and\nsolved by numerical methods. The solution is shown to have the expected\nproperties: at very small scales (a<<L) the energy density behaves as\npressureless dust, at very large scales (a>>L) as a cosmological constant. The\nmodifications to the DGP model and the Chaplygin gas model occur for values of\na L. The results show an increase in the present dark energy density relative\nto the plain DGP model.", "We present a numerical method for the investigation of non-ergodic effects in\nthe Coulomb glass. For that, an almost complete set of low-energy many-particle\nstates is obtained by a new algorithm. The dynamics of the sample is mapped to\nthe graph formed by the relevant transitions between these states, that means\nby transitions with rates larger than the inverse of the duration of the\nmeasurement. The formation of isolated clusters in the graph indicates\nnon-ergodicity. We analyze the connectivity of this graph in dependence on\ntemperature, duration of measurement, degree of disorder, and dimensionality,\nstudying how non-ergodicity is reflected in the specific heat.", "The morphological and spectroscopic properties of the giant (>60 kpc)\nLy-alpha nebulae associated with three radio galaxies at z~2.5 (MRC 1558-003,\nMRC 2025-218 and MRC 0140-257) have been investigated using integral field\nspectroscopic data obtained with VIMOS on VLT.\n  The morphologies are varied. The nebula of one source has a centrally peaked,\nrounded appearance. In the other two objects, it consists of two spatial\ncomponents. The three nebulae are aligned with the radio axis within <30 deg.\nThe total Ly-alpha luminosities are in the range (0.3-3.4) x 1e44 erg s-1. The\nLy-alpha spectral profile shows strong variation through the nebulae, with FWHM\nvalues in the range ~400-1500 km s-1 and velocity shifts V~120-600 km s-1.\n  We present an infall model which can explain successfully most Ly-alpha\nmorphological and spectroscopic properties of the nebula associated with MRC\n1558-003. This adds further support to our previous conclusion that the\n_quiescent_ giant nebulae associated with this and other high redshift powerful\nradio galaxies are in infall. A problem for this model is the difficulty to\nreproduce the large Ly-alpha FWHM values.\n  We have discovered a giant (~85 kpc) Ly-alpha nebula associated with the\nradio galaxy MRC 0140-257 at z=2.64. It shows strikingly relaxed kinematics\n(FWHM< 300 km s-1 and V<120 km s-1), unique among high z (>2) radio galaxies.", "We report on a strong coupling approach (on-site Coulomb repulsion, U larger\nthan the nearest-neighbour hopping energy |t|) to the Hubbard model. Starting\nfrom the Hubbard operators which diagonalize the interaction term, we generate\na hierarchy of composite operators from the equations of motion. Using the\nHubbard operators as a basis, we are able to compute the associated Green\nfunctions including the anomalous Green functions which describe pair\nformation. We show explicitly that these anomalous Green functions are non-zero\nin the d_{x^2-y^2} channel; however, the entities that pair up are not single\nelectron-like particles but rather composite excitations (which we call cexons)\nmade out of an electron and a hole on nearest-neighbour sites. Cexons are\nfermionic in nature as they have spin 1/2 and also have unit charge. Our\ncalculations of the chemical potential reveal that negative compressibility in\nthe 2D Hubbard model and composite excitation pairing are intimately connected,\nnamely, the larger the negative compressibility, the larger the pairing\namplitude. Our observation of negative compressibility in the under-doped\nregime is consistent with phase segregation or stripe formation in the normal\nstate. While pairing ameliorates the negative compresssibility, it does not\neliminate it entirely. In addition, we find that the anomalous correlation\nfunctions are particle-hole symmetric and exhibit a maximum at a doping level\nof roughly 10% as measured from half-filling. For U=8|t|, the onset temperature\nfor pair formation is 0.02|t|.", "Atmospheric water vapor causes significant undesired phase fluctuations for\nthe Submillimeter Array (SMA) interferometer, particularly in its highest\nfrequency observing band of 690 GHz. One proposed solution to this atmospheric\neffect is to observe simultaneously at two separate frequency bands of 230 and\n690 GHz. Although the phase fluctuations have a smaller magnitude at the lower\nfrequency, they can be measured more accurately and on shorter timescales due\nto the greater sensitivity of the array to celestial point source calibrators\nat this frequency. In theory, we can measure the atmospheric phase fluctuations\nin the 230 GHz band, scale them appropriately with frequency, and apply them to\nthe data in 690 band during the post-observation calibration process. The\nultimate limit to this atmospheric phase calibration scheme will be set by the\ninstrumental phase stability of the IF and LO systems. We describe the\nmethodology and initial results of the phase stability characterization of the\nIF and LO systems.", "We investigate the liquid-solid transition of two dimensional hard spheres in\nthe presence of gravity. We determine the transition temperature and the\nfraction of particles in the solid regime as a function of temperature via\nEven-Driven molecular dynamics simulations and compare them with the\ntheoretical predictions. We then examine the configurational statistics of a\nvibrating bed from the view point of the liquid-solid transition by explicitly\ndetermining the transition temperature and the effective temperature, T, of the\nbed, and present a relation between T and the vibration strength.", "The BL Lac object 3C 66A was observed in an extensive multiwavelength\nmonitoring campaign from July 2003 till April 2004. The spectral energy\ndistribution (SED) was measured over the entire electromagnetic spectrum, with\nflux measurements from radio to X-ray frequencies and upper limits in the very\nhigh energy (VHE) gamma-ray regime. Here, we use a time-dependent leptonic jet\nmodel to reproduce the SED and optical spectral variability observed during our\nmultiwavelength campaign. Our model simulations could successfully reproduce\nthe observed SED and optical light curves and predict an intrinsic cutoff value\nfor the VHE gamma-ray emission at ~ 4 GeV. The effect of the optical depth due\nto the intergalactic infrared background radiation (IIBR) on the peak of the\nhigh-energy component of 3C 66A was found to be negligible. Also, the presence\nof a broad line region (BLR) in the case of 3C 66A may play an important role\nin the emission of gamma-ray photons when the emission region is very close to\nthe central engine, but further out, the production mechanism of hard X-ray and\ngamma-ray photons becomes rapidly dominated by synchrotron self-Compton\nemission. We further discuss the possibility of an observable X-ray spectral\nvariability pattern. The simulated results do not predict observable hysteresis\npatterns in the optical or soft X-ray regimes for major flares on multi-day\ntime scales.", "The study of the innermost circumstellar layers around AGB stars is crucial\nto understand how these envelopes are formed and evolve. The SiO maser emission\noccurs at a few stellar radii from the central star, providing direct\ninformation on the stellar pulsation and on the chemical and physical\nproperties of these regions. Our data also shed light on several aspects of the\nSiO maser pumping theory that are not well understood yet. We aim to determine}\nthe relative spatial distribution of the 43 GHz and 86 GHz SiO maser lines in\nthe oxygen-rich evolved star R Leo. We have imaged with milliarcsecond\nresolution, by means of Very Long Baseline Interferometry, the 43 GHz (28SiO\nv=1, 2 J=1-0 and 29SiO v=0 J=1-0) and 86 GHz (28SiO v=1 J=2-1 and 29SiO v=0\nJ=2-1) masing regions. We confirm previous results obtained in other\noxygen-rich envelopes. In particular, when comparing the 43 GHz emitting\nregions, the 28SiO v=2 transition is produced in an inner layer, closer to the\ncentral star. On the other hand, the 86 GHz line arises in a clearly farther\nshell. We have also mapped for the first time the 29SiO v=0 J=1-0 emission in R\nLeo. The already reported discrepancy between the observed distributions of the\ndifferent maser lines and the theoretical predictions is also found in R Leo.", "We discuss the emission of gravitational radiation produced in encounters of\ndark matter galactic halos. To this aim we perform a number of numerical\nsimulations of typical galaxy mergers, computing the associated gravitational\nradiation waveforms as well as the energy released in the processes. Our\nsimulations yield dimensionless gravitational wave amplitudes of the order of\n$10^{-13}$ and gravitational wave frequencies of the order of $10^{-16}$ Hz,\nwhen the galaxies are located at a distance of 10 Mpc. These values are of the\nsame order as those arising in the gravitational radiation originated by strong\nvariations of the gravitational field in the early Universe, and therefore,\nsuch gravitational waves cannot be directly observed by ground-based detectors.\nWe discuss the feasibility of an indirect detection by means of the B-mode\npolarization of the Cosmic Microwave Background (CMB) induced by such waves.\nOur results show that the gravitational waves from encounters of dark matter\ngalactic halos leave much too small an imprint on the CMB polarization to be\nactually observed with ongoing and future missions.", "We show the locations of the SWIFT short hard bursts (SHB) with afterglows on\nthe galactic map and compare with the VSB BATSE events. As we have pointed out\nbefore, there is an excess of events in the galactic map of BATSE VSB events.\nWe not that none of VSB SWIFT era events fall into this cluster. More SWIFT\nevents are needed to check this claim. We also report a new study with KONUS\ndata of the VSB sample with an average energy above 90 keV showing a clear\nexcess of events below 100 ms duration (T90) that have large mean energy\nprotons. We suggest that VSB themselves consist of two subclasses: a fraction\nof events have peculiar distribution properties and have no detectable\ncounterparts, as might be expected for exotic sources such as primordial black\nholes. We show how GLAST could add key new information to the study of VSB\nbursts and could help test the black hole concept.", "In papers I and II in this series, we presented hydrodynamical simulations of\njet models with parameters representative of the symbiotic system MWC 560.\nThese were simulations of a pulsed, initially underdense jet in a high density\nambient medium. Since the pulsed emission of the jet creates internal shocks\nand since the jet velocity is very high, the jet bow shock and the internal\nshocks are heated to high temperatures and should therefore emit X-ray\nradiation. In this paper, we investigate in detail the X-ray properties of the\njets in our models. We have focused our study on the total X-ray luminosity and\nits temporal variability, the resulting spectra and the spatial distribution of\nthe emission. Temperature and density maps from our hydrodynamical simulations\nwith radiative cooling presented in the second paper are used together with\nemissivities calculated with the atomic database ATOMDB. The jets in our models\nshow extended and variable X-ray emission which can be characterized as a sum\nof hot and warm components with temperatures that are consistent with\nobservations of CH Cyg and R Aqr. The X-ray spectra of our model jets show\nemission line features which correspond to observed features in the spectra of\nCH Cyg. The innermost parts of our pulsed jets show iron line emission in the\n6.4 - 6.7 keV range which may explain such emission from the central source in\nR Aqr. We conclude that MWC 560 should be detectable with Chandra or\nXMM-Newton, and such X-ray observations will provide crucial for understanding\njets in symbiotic stars.", "The question whether the dark matter halo density in the centers of galaxies\ncould be changed through interactions with a rotating bar in the baryonic disk\nis of considerable current interest. While N-body simulations have been used to\naddress this question, it has also been claimed that results from such\nsimulations cannot be trusted. Based on a perturbative treatment of resonant\nexchanges between orbits and a rotating perturbation, Weinberg & Katz contend\nthat N-body simulations of this process will not reveal the continuum result\nunless many more than the usual numbers of particles are employed. Here I\nreport a study designed to examine their contention, finding results that show\nno dependence on the number of particles over the range usually employed up to\nthat advocated by these authors. I show that my results are independent of all\nnumerical parameters, and that field methods perform equally with grid methods\nin this respect. I also identify the reasons that the required particle number\nsuggested by Weinberg & Katz is excessive.", "We carried out a target survey for Lyman break galaxies (LBGs) and Lyman\nalpha emitters (LAEs) around QSO SDSS J0211-0009 at z=4.87. The deep and wide\nbroadband and narrowband imaging simultaneously revealed the perspective\nstructure of these two high-z populations. The LBGs without Ly-alpha emission\nform a filamentary structure including the QSO, while the LAEs are distributed\naround the QSO but avoid it within a distance of ~4.5Mpc. On the other hand, we\nserendipitously discovered a protocluster with a significant concentration of\nLBGs and LAEs where no strongly UV ionizing source such as a QSO or radio\ngalaxy is known to exist. In this cluster field, two populations are spatially\ncross-correlated with each other. The relative spatial distribution of LAEs to\nLBGs is in stark contrast between the QSO and the cluster fields. We also found\na weak trend showing that the number counts based on Ly-alpha and UV continuum\nfluxes of LAEs in the QSO field are slightly lower than in the cluster field,\nwhereas the number counts of LBGs are almost consistent with each other. The\nLAEs avoid the nearby region around the QSO where the local UV background\nradiation could be ~100 times stronger than the average for the epoch. The\nclustering segregation between LBGs and LAEs seen in the QSO field could be due\nto either enhanced early galaxy formation in an overdense environment having\ncaused all the LAEs to evolve into LBGs, or local photoionization due to the\nstrong UV radiation from the QSO effectively causing a deficit in low-mass\ngalaxies like LAEs.", "It has been shown based on radio variability arguments that some BALQSOs\n(broad absorption line quasars) are viewed along the polar axis (orthogonal to\naccretion disk) in the recent article of Zhou et al. These arguments are based\non the brightness temperature, $T_{b}$ exceeding $10^{12} ^{\\circ}$ K which\nleads to the well-known inverse Compton catastrophe unless the radio jet is\nrelativistic and is viewed along its axis. In this letter, we expand the Zhou\net al sample of polar BALQSOs to the entire SDSS DR5. In the process, we\nclarify a mistake in their calculation of brightness temperature. The expanded\nsample of high $T_{b}$ BALQSOS, has an inordinately large fraction of LoBALQSOs\n(low ionization BALQSOs). We consider this an important clue to understanding\nthe nature of the polar BALQSOs. This is expected in the polar BALQSO\nanalytical/numerical models of Punsly in which LoBALQSOs occur when the line of\nsight is very close to the polar axis, where the outflow density is the\nhighest.", "We construct a family of electronic ladder models with SO(5) symmetry which\nhave exact ground states in the form of finitely correlated wave functions.\nExtensions for these models preserving this symmetry are studied using these\nstates in a variational approach. Within this approach, the zero temperature\nphase diagram of these electronic ladders at half filling is obtained,\nreproducing the known results in the weak coupling (band insulator) and strong\ncoupling regime, first studied by Scalapino, Zhang and Hanke. Finally, the\ncompact form of the variational wave functions allows to compute various\ncorrelation functions for these systems.", "We study the statics and the dynamics of domain patterns in proper\nhexagonal-orthorhombic ferroelastics; these patterns are of particular interest\nbecause they provide a rare physical realization of disclinations in crystals.\nBoth our static and dynamical theories are based entirely on classical,\nnonlinear elasticity theory; we use the minimal theory consistent with\nstability, symmetry and ability to explain qualitatively the observed patterns.\nAfter scaling, the only parameters of the static theory are a temperature\nvariable and a stiffness variable. For moderate to large stiffness, our static\nresults show nested stars, unnested stars, fans and other nodes, triangular and\ntrapezoidal regions of trapped hexagonal phase, etc observed in electron\nmicroscopy of Ta4N and Mg-Cd alloys, and also in lead orthovanadate (which is\ntrigonal-monoclinic); we even find imperfections in some nodes, like those\nobserved. For small stiffness, we find patterns like those observed in the\nmineral Mg-cordierite. Our dynamical studies of growth and relaxation show the\nformation of these static patterns, and also transitory structures such as\n12-armed bursts, streamers and striations which are also seen experimentally.\nThe major aspects of the growth-relaxation process are quite unlike those in\nsystems with conventional order parameters, for it is inherently nonlocal; for\nexample, the changes from one snapshot to the next are not predictable by\ninspection.", "We compare the CO 2-1 observations against previously taken CO 4-3\nobservations and analyze the spatial distribution of young stellar objects\n(YSO's) within the cloud using the Spitzer IRAC observations of the 30 Doradus\ncomplex. Both peaks of CO 2-1 and 4-3 emitting clouds coincide with the densest\nregion of the filaments where multiple shells are colliding. We find that the\nYSO's are clustered in the southern ridge of the warm and dense molecular gas\nclouds traced by CO J=4-3, indicating a filamentary structure of star formation\nthroughout the 30 Doradus. We also find that some of Class I YSO's candidates\nwhich are likely to be associated with a high-velocity component of CO 4-3\nemitting clouds are present. This is a bona fide place where the triggered star\nformation had happened and newly formed stars may have produced such a\nhigh-velocity outflow interacting with the surrounding molecular cloud\nmaterial.", "Multispecies reaction-diffusion systems, for which the time evolution\nequation of correlation functions become a closed set, are considered. A formal\nsolution for the average densities is found. Some special interactions and the\nexact time dependence of the average densities in these cases are also studied.\nFor the general case, the large time behaviour of the average densities has\nalso been obtained.", "We report a theory for analyzing nonlinear DC transport properties of\nmesoscopic or nanoscopic normal-superconducting (N-S) systems. Special\nattention was paid such that our theory satisfies gauge invariance. At the\nlinear transport regime and the sub-gap region where the familiar scattering\nmatrix theory has been developed, we provide confirmation that our theory and\nthe scattering matrix theory are equivalent. At the nonlinear regime, however,\nour theory allows the investigation of a number of important problems: for N-S\nhybrid systems we have derived the general nonlinear current-voltage\ncharacteristics in terms of the scattering Green's function, the second order\nnonlinear conductance at the weakly nonlinear regime, and nonequilibrium charge\npile-up in the device which defines the electrochemical capacitance\ncoefficients.", "Mean-field-theory predicts that the Curie temperature T_c of a (III,Mn)V\nferromagnet will be proportional to the valence band density-of-states of its\nhost (III,V) semiconductor, suggesting a route toward room-temperature\nferromagnetism in this materials class. In this Letter, we use theoretical\nestimates of spin-wave energies and Monte-Carlo simulations to demonstrate that\nlong-wavelength collective fluctuations, neglected by mean-field theory, will\nlimit the critical temperature in large density-of-states materials. We discuss\nimplications for high T_c searches.", "Using the Jordan-Wigner fermionization, Green function approach and continued\nfractions we examine rigorously the local magnetizations and the local static\nsusceptibilities of the spin-1/2 XX chain in a transverse field with regularly\nvarying exchange interactions. We discuss our findings from a viewpoint of the\nstrong-coupling approach.", "We present the optical identification and spectroscopy of the host galaxy of\nGRB 050826 at a redshift z = 0.296 +/- 0.001. Image subtraction among\nobservations obtained on three consecutive nights, reveals a fading object 5\nhours after the burst, confirming its identification as the optical afterglow\nof this event. Deep imaging shows that the optical afterglow is offset by 0.4\narcseconds (~1.76 kpc) from the center of its irregular host galaxy, which is\ntypical for long-duration gamma-ray bursts. Combining these results with X-ray\nmeasurements acquired by the Swift XRT instrument, we find that GRB 050826\nfalls entirely within the subluminous, subenergetic group of long gamma-ray\nbursts at low redshift (z < 0.3). The results are discussed in the context of\nmodels that possibly account for this trend, including the nature of the\ncentral engine, the evolution of progenitor properties as a function of\nredshift, and incompleteness in current gamma-ray burst samples.", "Massive stars, supernovae (SNe), and long-duration gamma-ray bursts (GRBs)\nhave a huge impact on their environment. Despite their importance, a\ncomprehensive knowledge of which massive stars produce which SN/GRB is hitherto\nlacking. We present a brief overview about our knowledge of mass loss in the\nHertzsprung-Russell Diagram (HRD) covering evolutionary phases of the OB main\nsequence, the unstable Luminous Blue Variable (LBV) stage, and the Wolf-Rayet\n(WR) phase. Despite the fact that metals produced by ``self-enrichment'' in WR\natmospheres exceed the initial -- host galaxy -- metallicity, by orders of\nmagnitude, a particularly strong dependence of the mass-loss rate on the\ninitial metallicity is found for WR stars at sub-solar metallicities (1/10 --\n1/100 solar). This provides a significant boost to the collapsar model for\nGRBs, as it may present a viable mechanism to prevent the loss of angular\nmomentum by stellar winds at low metallicity, whilst strong Galactic WR winds\nmay inhibit GRBs occurring at solar metallicities. Furthermore, we discuss\nrecently reported quasi-sinusoidal modulations in the radio lightcurves of SNe\n2001ig and 2003bg. We show that both the sinusoidal behaviour and the\nrecurrence timescale of these modulations are consistent with the predicted\nmass-loss behaviour of LBVs, and we suggest LBVs may be the progenitors of some\ncore-collapse SNe.", "Supermassive black hole (BH) masses (MBH) are strongly correlated with galaxy\nstellar bulge masses (Mbulge) and there are several ideas to explain the origin\nof this relationship. This study isolates the role of galaxy mergers from\nconsiderations of other detailed physics to more clearly show how a linear\nBH-galaxy mass relation (MBH-Mgal) can naturally emerge regardless of how\nprimordial BHs were seeded inside galaxies, if the galaxy mass function\ndeclines with increasing mass. Under this circumstance, the MBH-Mgal relation\nis a passive attractor that eventually converges to a tight linear relation\nbecause of two basic statistical effects: a central limit-like tendency for\ngalaxy mergers which is much stronger for major mergers than minor mergers, and\na convergence toward a linear relation that is due mainly to minor mergers. A\ncurious consequence of this thought experiment is that, if galaxy bulges are\nformed by major mergers, then merging statistics naturally show that MBH would\ncorrelate more strongly with bulge dominated galaxies, because of stronger\ncentral-seeking tendencies, than with disk dominated galaxies. Even if some\nother physics is ultimately responsible for causing a linear MBH-Mbulge\nrelationship, this thought experiment shows that, counter to intuition, random\nmerging of galaxies that harbor random BH masses tends to strengthen rather\nthan weaken a pre-existing, linear, correlation. This idea may be generalized\nto other gravitationally bound systems (dark matter halo, compact nuclear\nobjects) that retain their physical identities after experiencing mergers.", "In this topical review I revisit the \"chromospheric flare.\" This should\ncurrently be an outdated concept, because modern data seem to rule out the\npossiblity of a major flare happening independently in the chromosphere alone,\nbut the chromosphere still plays a major observational role in many ways. It is\nthe source of the bulk of a flare's radiant energy - in particular the\nvisible/UV continuum radiation. It also provides tracers that guide us to the\ncoronal source of the energy, even though we do not yet understand the\npropagation of the energy from its storage in the corona to its release in the\nchromosphere. The formation of chromospheric radiations during a flare presents\nseveral difficult and interesting physical problems.", "We have been monitoring Supernova (SN) 1987A with {\\it Chandra X-Ray\nObservatory} since 1999. We present a review of previous results from our {\\it\nChandra} observations, and some preliminary results from new {\\it Chandra} data\nobtained in 2006 and 2007. High resolution imaging and spectroscopic studies of\nSN 1987A with {\\it Chandra} reveal that X-ray emission of SN 1987A originates\nfrom the hot gas heated by interaction of the blast wave with the ring-like\ndense circumstellar medium (CSM) that was produced by the massive progenitor's\nequatorial stellar winds before the SN explosion. The blast wave is now\nsweeping through dense CSM all around the inner ring, and thus SN 1987A is\nrapidly brightening in soft X-rays. At the age of 20 yr (as of 2007 January),\nX-ray luminosity of SN 1987A is $L_{\\rm X}$ $\\sim$ 2.4 $\\times$ 10$^{36}$ ergs\ns$^{-1}$ in the 0.5$-$10 keV band. X-ray emission is described by two-component\nplane shock model with electron temperatures of $kT$ $\\sim$ 0.3 and 2 keV. As\nthe shock front interacts with dense CSM all around the inner ring, the X-ray\nremnant is now expanding at a much slower rate of $v$ $\\sim$ 1400 km s$^{-1}$\nthan it was until 2004 ($v$ $\\sim$ 6000 km s$^{-1}$).", "We present the results of our investigation of the intermediate-age star\ncluster BS 90, located in the vicinity of the HII region N 66 in the SMC,\nobserved with HST/ACS. The high-resolution data provide a unique opportunity\nfor a very detailed photometric study performed on one of the rare\nintermediate-age rich SMC clusters. The complete set of observations is\ncentered on the association NGC 346 and contains almost 100,000 stars down to V\n~28 mag. In this study we focus on the northern part of the region, which\ncovers almost the whole stellar content of BS 90. We construct its stellar\nsurface density profile and derive structural parameters. Isochrone fits on the\nCMD of the cluster results in an age of about 4.5 Gyr. The luminosity function\nis constructed and the present-day mass function of BS 90 has been obtained\nusing the mass-luminosity relation, derived from the isochrone models. We found\na slope between -1.30 and -0.95, comparable or somewhat shallower than a\ntypical Salpeter IMF. Examination of the radial dependence of the mass function\nshows a steeper slope at larger radial distances, indicating mass segregation\nin the cluster. The derived half-mass relaxation time of 0.95 Gyr suggests that\nthe cluster is mass segregated due to its dynamical evolution. From the\nisochrone model fits we derive a metallicity for BS 90 of [Fe/H]=-0.72, which\nadds an important point to the age-metallicity relation of the SMC. We discuss\nour findings on this relation in comparison to other SMC clusters.", "We investigate the properties of a degenerate dilute gas of neutral fermionic\nparticles in a harmonic trap that interact via dipole-dipole forces. We employ\nthe semiclassical Thomas-Fermi method and discuss the Dirac correction to the\ninteraction energy. A nearly analytic as well as an exact numerical\nminimization of the Thomas-Fermi-Dirac energy functional are performed in order\nto obtain the density distribution. We determine the stability of the system as\na function of the interaction strength, the particle number, and the trap\ngeometry. We find that there are interaction strengths and particle numbers for\nwhich the gas cannot be trapped stably in a spherically symmetric trap, but\nboth prolate and oblate traps will work successfully.", "Using non-linear response theory the time signals relevant for nonresonant\nspectral hole burning are calculated. The step-reponse function following the\napplication of a high amplitude ac field (pump) and an intermediate waiting\nperiod is shown to be the sum of the equilibrium integrated response and a\nmodification due to the preparation via ac irradiation. Both components are\ncalculated for a class of stochastic dipole reorientation models. The results\nindicate that the method can be used for a clearcut distinction of\nhomogeneously and heterogeneously broadened susceptibilities as they occur in\nthe relaxation of supercooled liquids or other disordered materials. This is\nbecause only in the heterogeneous case is a frequency selective modification of\nthe response possible.", "The star HE 1305-0007 is a metal-poor double-enhanced star with metallicity\n[Fe/H] $=-2.0$, which is just at the upper limit of the metallicity for the\nobserved double-enhanced stars. Using a parametric model, we find that almost\nall s-elements were made in a single neutron exposure. This star should be a\nmember of a post-common-envelope binary. After the s-process material has\nexperienced only one neutron exposure in the nucleosynthesis region and is\ndredged-up to its envelope, the AGB evolution is terminated by the onset of\ncommon-envelope evolution. Based on the high radial-velocity of HE 1305-0007,\nwe speculate that the star could be a runaway star from a binary system, in\nwhich the AIC event has occurred and produced the r-process elements.", "We have studied the wetting properties of He4 adsorbed on the surface of\nheavy alkali metals by using a non-local free-energy density-functional which\ndescribes accurately the surface properties of liquid He4 in the temperature\nrange 0<T<3 K.Our results for He4 on the Cs surface give both the temperature\ndependence of the contact angle and the wetting temperature in good agreement\nwith the experimental findings. For the He/Rb system we find that a wetting\ntransition on the Rb surface occurs at T=1.4 K, whereas the experiments show\neither wetting down to T=0 or a wetting transition at T=0.3 K. We suggest that\nthis disagreement is due either to an inaccuracy of the fluid-substrate\npotential used in our calculations or the consequence of substrate roughness,\nwhich is known to affect the Rb surface, and whose effect would be to lower the\nwetting temperature. The sensitivity of the wetting transition to the\nHe-surface potential are stressed for the He/Rb surface, which may justify the\ncontroversial experimental findings for this system.", "The variation of the expansion rate of the Universe with time produces an\nevolution in the cosmological redshift of distant sources (for example quasar\nLyman-$\\alpha$ absorption lines), that might be directly observed by future\nultra stable, high-resolution spectrographs (such as CODEX) coupled to\nextremely large telescopes (such as European Southern Observatory's Extremely\nLarge Telescope, ELT). This would open a new window to explore the physical\nmechanism responsible for the current acceleration of the Universe. We\ninvestigate the evolution of cosmological redshift from a variety of dark\nenergy models, and compare it with simulated data. We perform a Fisher matrix\nanalysis and discuss the prospects for constraining the parameters of these\nmodels and for discriminating among competing candidates. We find that, because\nof parameter degeneracies, and of the inherent technical difficulties involved\nin this kind of observations, the uncertainties on parameter reconstruction can\nbe rather large unless strong external priors are assumed. However, the method\ncould be a valuable complementary cosmological tool, and give important\ninsights on the dynamics of dark energy, not obtainable using other probes.", "We have carried out first principles electronic structure and total energy\ncalculations for a series of ultrathin aluminum nanowires, based on structures\nobtained by relaxing the model wires of Gulseren et al. The number of\nconducting channels is followed as the wires radius is increased. The results\nsuggest that pentagonal wires should be detectable, as the only ones who can\nyield a channel number between 8 and 10.", "We describe XMM-Newton observations taken 4.3 days prior to and 1.5 days\nsubsequent to two remarkable events that were detected with Swift on 2006\nSeptember 21 from the candidate magnetar CXOU J164710.2-455216: (1) a 20 ms\nburst with an energy of 1e37 erg (15-150 keV), and (2) a rapid spin-down\n(glitch) with a fractionap period change of 1e-4. We find that the luminosity\nof the pulsar increased by a factor of 100 in the interval between\nobservations, from 1e33 to 1e35 erg/s (0.5-8.0 keV), and that its spectrum\nhardened. The pulsed count rate increased by a factor of 10 (0.5-8.0 keV), but\nthe fractional rms amplitude of the pulses decreased from 65 to 11 per cent,\nand their profile changed from being single-peaked to exhibiting three peaks.\nSimilar changes have been observed from other magnetars in response to\noutbursts, such as that of 1E 2259+586 in 2002 June. We suggest that a plastic\ndeformation of the neutron star's crust induced a very slight twist in the\nexternal magnetic field, which in turn generated currents in the magnetosphere\nthat were the direct cause of the X-ray outburst.", "The magnetic molecule Fe_8 has been predicted and observed to have a rich\npattern of degeneracies in its spectrum as an external magnetic field is\nvaried. These degeneracies have now been recognized to be diabolical points.\nThis paper analyzes the diabolicity and all essential properties of this system\nusing elementary perturbation theory. A variety of arguments is gievn to\nsuggest that an earlier semiclassical result for a subset of these points may\nbe exactly true for arbitrary spin", "We report new magnetic field measurements for 14 classical T Tauri stars\n(CTTSs). We combine these data with one previous field determination in order\nto compare our observed field strengths with the field strengths predicted by\nmagnetospheric accretion models. We use literature data on the stellar mass,\nradius, rotation period, and disk accretion rate to predict the field strength\nthat should be present on each of our stars according to these magnetospheric\naccretion models. We show that our measured field values do not correlate with\nthe field strengths predicted by simple magnetospheric accretion theory. We\nalso use our field strength measurements and literature X-ray luminosity data\nto test a recent relationship expressing X-ray luminosity as a function of\nsurface magnetic flux derived from various solar feature and main sequence star\nmeasurements. We find that the T Tauri stars we have observed have weaker than\nexpected X-ray emission by over an order of magnitude on average using this\nrelationship. We suggest the cause for this is actually a result of the very\nstrong fields on these stars which decreases the efficiency with which gas\nmotions in the photosphere can tangle magnetic flux tubes in the corona.", "We investigate the ground and low excited states of a rotating, weakly\ninteracting Bose-Einstein condensed gas in a harmonic trap for a given angular\nmomentum. Analytical results in various limits, as well as numerical results\nare presented, and these are compared with those of previous studies. Within\nthe mean-field approximation and for repulsive interaction between the atoms,\nwe find that for very low values of the total angular momentum per particle,\n$L/N \\to 0$, where $L \\hbar$ is the angular momentum and $N$ is the total\nnumber of particles, the angular momentum is carried by quadrupolar ($|m| = 2$)\nsurface modes. For $L/N =1$ a vortex-like state is formed and all the atoms\noccupy the $m=1$ state. For small negative values of $L/N-1$ the states with\n$m=0$ and $m=2$ become populated, and for small positive values of $L/N-1$\natoms in the states with $m=5$ and $m=6$ carry the additional angular momentum.\nIn the whole region $0 \\le L/N \\le 1$ we have strong analytic and numerical\nevidence that the interaction energy drops linearly as a function of $L/N$. We\nhave also found that an array of singly quantized vortices is formed as $L/N$\nincreases. Finally we have gone beyond the mean-field approximation and have\ncalculated the energy of the lowest state up to order $N$ for small negative\nvalues of $L/N-1$, as well as the energy of the low-lying excited states.", "The quasi-static frequency response of a granular medium is measured by a\nforced torsion oscillator method, with forcing frequency $f_{p}$ in the range\n$10^{-4}$ Hz to 5 Hz, while weak vibrations at high-frequency $f_{s}$, in the\nrange 50 Hz to 200 Hz, are generated by an external shaker. The intensity of\nvibration, $\\Gamma $, is below the fluidization limit. A loss factor peak is\nobserved in the oscillator response as a function of $\\Gamma $ or $f_{p}$. In a\nplot of $\\ln f_{p}$ against $1/\\Gamma $, the position of the peak follows an\nArrhenius-like behaviour over four orders of magnitude in $f_{p}$. The data can\nbe described as a stochastic hopping process involving a probability factor\n$\\exp(-\\Gamma_{j}/\\Gamma)$ with $\\Gamma_{j}$ a $f_{s}$-dependent characteristic\nvibration intensity. A $f_{s}$-independent description is given by\n$\\exp(-\\tau_{j}/\\tau)$, with $\\tau_{j}$ an intrinsic characteristic time, and\n$\\tau =\\Gamma ^{n}/2\\pi f_{s}$, n=0.5-0.6, an empirical control parameter with\nunit of time. $\\tau$ is seen as the effective average time during which the\nperturbed grains can undergo structural rearrangement. The loss factor peak\nappears as a crossover in the dynamic behaviour of the vibrated granular\nsystem, which, at the time-scale $ 1/f_{p}$, is solid-like at low $\\Gamma$, and\nthe oscillator is jammed into the granular material, and is fluid-like at high\n$\\Gamma$, where the oscillator can slide viscously.", "We provide a new estimate of the local supermassive black hole mass function\nusing (i) the empirical relation between supermassive black hole mass and the\nSersic index of the host spheroidal stellar system and (ii) the measured\n(spheroid) Sersic indices drawn from 10k galaxies in the Millennium Galaxy\nCatalogue. The observational simplicity of our approach, and the direct\nmeasurements of the black hole predictor quantity, i.e. the Sersic index, for\nboth elliptical galaxies and the bulges of disc galaxies makes it\nstraightforward to estimate accurate black hole masses in early- and late-type\ngalaxies alike. We have parameterised the supermassive black hole mass function\nwith a Schechter function and find, at the low-mass end, a logarithmic slope\n(1+alpha) of ~0.7 for the full galaxy sample and ~1.0 for the early-type galaxy\nsample. Considering spheroidal stellar systems brighter than M_B = -18 mag, and\nintegrating down to black hole masses of 10^6 M_sun, we find that the local\nmass density of supermassive black holes in early-type galaxies rho_{bh,\nearly-type} = (3.5+/-1.2) x 10^5 h^3_{70} M_sun Mpc^{-3}, and in late-type\ngalaxies rho_{bh, late-type} = (1.0+/-0.5) x 10^5 h^3_{70} M_sun Mpc^{-3}. The\nuncertainties are derived from Monte Carlo simulations which include\nuncertainties in the M_bh-n relation, the catalogue of Sersic indices, the\ngalaxy weights and Malmquist bias. The combined, cosmological, supermassive\nblack hole mass density is thus Omega_{bh, total} = (3.2+/-1.2) x 10^{-6} h_70.\nThat is, using a new and independent method, we conclude that (0.007+/-0.003)\nh^3_{70} per cent of the universe's baryons are presently locked up in\nsupermassive black holes at the centres of galaxies.", "We review the current theory of atom lasers. A tutorial treatment of second\nquantisation and the Gross-Pitaevskii equation is presented, and basic concepts\nof coherence are outlined. The generic types of atom laser models are surveyed\nand illustrated by specific examples. We conclude with detailed treatments of\nthe mechanisms of gain and output coupling.", "We introduce an analytical model based on birth-death clustering processes to\nhelp understanding the empirical log-periodic corrections to power-law scaling\nand the finite-time singularity as reported in several domains including\nrupture, earthquakes, world population and financial systems. In our\nstochastics theory log-periodicities are a consequence of transient clusters\ninduced by an entropy-like term that may reflect the amount of cooperative\ninformation carried by the state of a large system of different species. The\nclustering completion rates for the system are assumed to be given by a simple\nlinear death process. The singularity at t_{o} is derived in terms of\nbirth-death clustering coefficients.", "We perform a series of two-dimensional magnetorotational core-collapse\nsimulations of Pop III stars. Changing the initial distributions of rotation\nand magnetic fields prior to collapse in a parametric manner, we compute 19\nmodels. By so doing, we systematically investigate how rotation and magnetic\nfields affect the collapse dynamics and explore how the properties of the\nblack-hole formations and neutrino emissions could be affected. As for the\nmicrophysics, we employ a realistic equation of state and approximate the\nneutrino transfer by a multiflavour leakage scheme. With these computations, we\nfind that the jet-like explosions are obtained by the magnetodriven shock waves\nif the initial magnetic field is as large as $10^{12}$ G. We point out that the\nblack-hole masses at the formation decrease with the initial field strength, on\nthe other hand, increase with the initial rotation rates. As for the neutrino\nproperties, we point out that the degree of the differential rotation plays an\nimportant role to determine which species of the neutrino luminosity is more\ndominant than the others. Furthermore, we find that the stronger magnetic\nfields make the peak neutrino luminosities smaller, because the magnetic\npressure acts to halt the collapse in the central regions, leading to the\nsuppression of the releasable gravitational binding energies.", "The experimental demonstration of Bose-Einstein condensation in atomic vapors\nhas rapidly lead to new advances in atom optics. It is now well established\nthat two-body collisions play for matter waves a role analogous to that of a\nKerr nonlinear crystal in optics. In particular, it is known that the nonlinear\nSchr\\\"odinger equation which describes the condensate supports soliton\nsolutions. For the case of repulsive interactions normally encountered in BEC\nexperiments, the simplest solutions are dark solitons, that is, 'dips' in the\ndensity profile of the condensate. However, it is desirable to achieve the\ndispersionless transport of a spatially localized ensemble of atoms, rather\nthan a 'hole'. In that case, bright solitons are much more interesting although\nthe problem is that large condensates are necessarily associated with repulsive\ninteractions, for which bright solitons might seem impossible. While this is\ntrue for atoms in free space, this is however not the case for atoms in\nsuitable potentials, eg. optical lattices. This result is known from nonlinear\noptics, where such soliton solutions, called gap solitons, have been predicted\nand demonstrated. We will briefly review the basic formalism for nonlinear atom\noptics and summarize various soliton solutions and then describe a specific\nmodel for gap solitons in a spinor Bose-Einstein condensate.", "We demonstrate that the nonlinear mean-field shift in a multi-component\nBose-Einstein condensate may be eliminated by controlling the two-body\ninteraction coefficients. This modification is achieved by, e.g., suitably\nengineering the environment of the condensate. We consider as an example the\ncase of a two-component condensate in a tightly confining atom waveguide.\nModification of the atom-atom interactions is then achieved by varying\nindependently the transverse wave function of the two components. Eliminating\nthe density dependent phase shift in a high-density atomic beam has important\napplications in atom interferometry and precision measurement.", "We describe results of a narrow band search for ultra-strong emission line\ngalaxies (USELs) with EW(H beta) > 30 A. 542 candidate galaxies are found in a\nhalf square degree survey using two ~100 Angstrom 8150 A and 9140 A filters\nwith Subaru/SuprimeCam. Followup spectroscopy for randomly selected objects in\nthe sample with KeckII/DEIMOS shows they consist of [OIII] 5007, [OII] 3727,\nand H alpha selected strong-emission line galaxies at intermediate redshifts (z\n< 1), and Ly alpha emitting galaxies at high-redshift (z >> 5). We determine\nthe H beta luminosity functions and the star formation density of the USELs,\nwhich is 5-10% of the value found from ultraviolet continuum objects at z=0-1,\nsuggesting they correspond to a major epoch in galaxy formation at these\nredshifts. Many USELs show the temperature-sensitive [OIII] 4363 auroral lines\nand about a dozen have oxygen abundances characteristic of eXtremely Metal Poor\nGalaxies (XMPGs). These XMPGs are the most distant known today. Our high yield\nrate of XMPGs suggests this is a powerful method for finding such populations.\nThe lowest metallicity measured in our sample is 12+log(O/H) = 7.06\n(6.78-7.44), close to the minimum metallicity found in local galaxies. The\nluminosities, metallicities and star formation rates of USELs are consistent\nwith the strong emitters being start-up intermediate mass galaxies and suggest\nthat galaxies are still forming in relatively chemically pristine sites at z <\n1.", "We consider a model of $N$ two-dimensional bosons in a harmonic potential\nwith weak repulsive delta-function interactions. We show analytically that, for\nangular momentum $L\\le N$, the elementary symmetric polynomials of particle\ncoordinates measured from the center of mass are exact eigenstates with energy\n$N(N-L/2-1)$. Extensive numerical analysis confirms that these are actually the\nground states, but we are currently unable to prove this analytically. The\nspecial case $L=N$ can be thought of as the generalisation of the usual\nsuperfluid one-vortex state to Bose-Einstein condensates in a trap.", "By 2D hydrodynamic simulations including a detailed equation of state and\nneutrino transport, we investigate the interplay between different non-radial\nhydrodynamic instabilities that play a role during the postbounce accretion\nphase of collapsing stellar cores. The convective mode of instability, which is\ndriven by negative entropy gradients caused by neutrino heating or by time\nvariations of the shock strength, can be identified clearly by the development\nof typical Rayleigh-Taylor mushrooms. However, in cases where the gas in the\npostshock region is rapidly advected towards the gain radius, the growth of\nsuch a buoyancy instability can be suppressed. In such a situation the shocked\nflow nevertheless can develop non-radial asymmetry with an oscillatory growth\nof the amplitude. This phenomenon has been termed ``standing accretion shock\ninstability'' (SASI). It is shown here that the SASI oscillations can trigger\nconvective instability and like the latter they lead to an increase of the\naverage shock radius and of the mass in the gain layer. Both hydrodynamic\ninstabilities in combination stretch the advection time of matter through the\nneutrino-heating layer and thus enhance the neutrino energy deposition in\nsupport of the neutrino-driven explosion mechanism. A rapidly contracting and\nmore compact nascent NS turns out to be favorable for explosions, because the\naccretion luminosity and neutrino heating are larger and the growth rate of the\nSASI is higher. Moreover, we show that the oscillation period of the SASI and a\nvariety of other features in our simulations agree with estimates for the\nadvective-acoustic cycle (AAC), in which perturbations are carried by the\naccretion flow from the shock to the neutron star and pressure waves close an\namplifying global feedback loop. (abridged)", "Fronts that start from a local perturbation and propagate into a linearly\nunstable state come in two classes: pulled and pushed. ``Pulled'' fronts are\n``pulled along'' by the spreading of linear perturbations about the unstable\nstate, so their asymptotic speed $v^*$ equals the spreading speed of linear\nperturbations of the unstable state. The central result of this paper is that\nthe velocity of pulled fronts converges universally for time $t\\to\\infty$ like\n$v(t)=v^*-3/(2\\lambda^*t) + (3\\sqrt{\\pi}/2)\nD\\lambda^*/(D{\\lambda^*}^2t)^{3/2}+O(1/t^2)$. The parameters $v^*$,\n$\\lambda^*$, and $D$ are determined through a saddle point analysis from the\nequation of motion linearized about the unstable invaded state. The interior of\nthe front is essentially slaved to the leading edge, and we derive a simple,\nexplicit and universal expression for its relaxation towards\n$\\phi(x,t)=\\Phi^*(x-v^*t)$. Our result, which can be viewed as a general center\nmanifold result for pulled front propagation, is derived in detail for the well\nknown nonlinear F-KPP diffusion equation, and extended to much more general\n(sets of) equations (p.d.e.'s, difference equations, integro-differential\nequations etc.). Our universal result for pulled fronts thus implies\nindependence (i) of the level curve which is used to track the front position,\n(ii) of the precise nonlinearities, (iii) of the precise form of the linear\noperators, and (iv) of the precise initial conditions. Our simulations confirm\nall our analytical predictions in every detail. A consequence of the slow\nalgebraic relaxation is the breakdown of various perturbative schemes due to\nthe absence of adiabatic decoupling.", "We show that the globular cluster mass function (GCMF) in the Milky Way\ndepends on cluster half-mass density (rho_h) in the sense that the turnover\nmass M_TO increases with rho_h while the width of the GCMF decreases. We argue\nthat this is the expected signature of the slow erosion of a mass function that\ninitially rose towards low masses, predominantly through cluster evaporation\ndriven by internal two-body relaxation. We find excellent agreement between the\nobserved GCMF -- including its dependence on internal density rho_h, central\nconcentration c, and Galactocentric distance r_gc -- and a simple model in\nwhich the relaxation-driven mass-loss rates of clusters are approximated by\n-dM/dt = mu_ev ~ rho_h^{1/2}. In particular, we recover the well-known\ninsensitivity of M_TO to r_gc. This feature does not derive from a literal\n``universality'' of the GCMF turnover mass, but rather from a significant\nvariation of M_TO with rho_h -- the expected outcome of relaxation-driven\ncluster disruption -- plus significant scatter in rho_h as a function of r_gc.\nOur conclusions are the same if the evaporation rates are assumed to depend\ninstead on the mean volume or surface densities of clusters inside their tidal\nradii, as mu_ev ~ rho_t^{1/2} or mu_ev ~ Sigma_t^{3/4} -- alternative\nprescriptions that are physically motivated but involve cluster properties\n(rho_t and Sigma_t) that are not as well defined or as readily observable as\nrho_h. In all cases, the normalization of mu_ev required to fit the GCMF\nimplies cluster lifetimes that are within the range of standard values\n(although falling towards the low end of this range). Our analysis does not\ndepend on any assumptions or information about velocity anisotropy in the\nglobular cluster system.", "The correlation functions are calculated for the two dimensional Ising model\nwith free boundary conditions and the two dimensional Ising model with periodic\nboundary conditions.", "GD 362 is a massive white dwarf with a spectrum suggesting a H-rich\natmosphere which also shows very high abundances of Ca, Mg, Fe and other\nmetals. However, for pure H-atmospheres the diffusion timescales are so short\nthat very extreme assumptions have to be made to account for the observed\nabundances of metals. The most favored hypothesis is that the metals are\naccreted from either a dusty disk or from an asteroid belt. Here we propose\nthat the envelope of GD 362 is dominated by He, which at these effective\ntemperatures is almost completely invisible in the spectrum. This assumption\nstrongly alleviates the problem, since the diffusion timescales are much larger\nfor He-dominated atmospheres. We also propose that the He-dominated atmosphere\nof GD 362 is likely to be the result of the merger of a binary white dwarf.", "We apply a new technique for ab initio phase determination [Acta Crystallogr.\nSect. A, A55, 48 (1999)] to solve for the average structure of the icosahedral\n(i) phase of AlPdMn. After an introduction to the crystallographic phase\nproblem and a description of the method, we present a brief report of our\nfindings for the structure of i(AlPdMn). Despite the use of data from extremely\nhigh quality samples, we find strong evidence of disorder in the structure,\nlending support to the random tiling model of quasicrystal stabilization.", "We report on XMM-Newton observations of three nearby galaxy pairs,\nAM0707-273, AM1211-465, and AM2040-674. All six galaxies were previously\nclassified as HII galaxies based on optical and IR spectroscopic analysis. All\ngalaxies were detected with XMM-Newton and each member was isolated and\nanalyzed independently. The X-ray spectra reveal strong evidence of AGN\nactivity in the NE member of AM1211-465 pair. We measured a luminosity of\n1.94(+0.11/-0.15)x10^42 erg/s in the 2-10 keV band and the presence of a\nneutral FeK_alpha line with a confidence level of 98.8%. The high nH value,\n2.2+/-0.2x10^22 cm^-2, would explain the misclassification of the source.\nMarginal evidence of AGN nature was found in the X-ray spectra of AM1211-465SW\nand AM0707-273E. The X-ray emission of the three remaining galaxies can be\nexplained by starburst activity.", "This paper extends earlier work on the definition of Wannier functions for\nBloch electrons in a magnetic field. Extensions to irrational as well as\nrational magnetic fields are defined, and their properties investigated. The\nresults are used to give a generalisation of the Peierls effective Hamiltonian\nwhich is valid when the magnetic flux per unit cell is close to any rational\nnumber.", "An orbital ordering, often observed in Mott insulators with orbital\ndegeneracy, is usually supposed to disappear with doping, e.g. in the\nferromagnetic metallic phase of manganites. We propose that the orbital\nordering of a novel type may exist in such situation: there may occur ferro\norbital ordering of complex orbitals (linear superposition of basic orbitals\nd_x^2-y^2 and d_z^2 with complex coefficients). Despite the perfect orbital\nordering, such state still retains cubic symmetry and thus would not induce any\nstructural distortion. This novel state can resolve many problems in the\nphysics of CMR manganites and can also exist in other doped Mott insulators\nwith Jahn-Teller ions.", "A spherically symmetrical ultra-relativistic blast wave is not an attractor\nof a generic asymmetric explosion. Spherical symmetry is reached only by the\ntime the blast wave slows down to non-relativistic velocities, when the\nSedov-Taylor-von Neumann attractor solution sets in. We show however, that a\ndirected relativistic explosion, with the explosion momentum close to the\nexplosion energy, produces a blast wave with a universal intermediate\nasymptotic -- a selfsimilar directed ultra-relativistic blast wave. This\nuniversality might be of interest for the astrophysics of gamma-ray burst\nafterglows.", "We show how a novel application of the theory of anelasticity unifies the\nobserved dynamics and proposed models of administered-rate products. This\ntheory yields a straightforward approach to rate model construction that we\nillustrate by simulating the observed relaxation dynamics of two administered\nrate products. We also demonstrate how the use of this formalism leads to a\nnatural definition of market friction.", "We have synthesized and characterized a new spin-1/2 Heisenberg\nantiferromagnetic ladder: bis 5-iodo-2-aminopyridinium tetrabromocuprate(II)\ndihydrate. X-ray diffraction studies show the structure of the compound to\nconsist of well isolated stacked ladders and the interaction between the Cu(2+)\natoms to be due to direct Br...Br contacts. Magnetic susceptibility and\nmagnetization studies show the compound to be in the strong-coupling limit,\nwith the interaction along the rungs (J' ~ 13 K) much greater than the\ninteraction along the rails (J ~ 1 K). Magnetic critical fields are observed\nnear 8.3 T and 10.4 T, respectively, establishing the existence of the energy\ngap.", "We show that observations of high-redshift Ly-alpha emitters (LAEs) have the\npotential to provide definitive evidence for reionization in the near future.\nUsing 200 Mpc radiative transfer simulations, we calculate the effect that\npatchy reionization has on the line profile, on the luminosity function, and,\nmost interestingly, on the clustering of emitters for several realistic models\nof reionization. Reionization increases the measured clustering of emitters,\nand we show that this enhancement would be essentially impossible to attribute\nto anything other than reionization. Our results motivate looking for the\nsignature of reionization in existing LAE data. We find that for stellar\nreionization scenarios the angular correlation function of the 58 LAEs in the\nSubaru Deep Field z = 6.6 photometric sample is more consistent with a fully\nionized universe (mean volume ionized fraction x_i = 1) than a universe with\nx_i < 0.5 at >2-sigma confidence level. Measurements in the next year on Subaru\nwill increase their z = 6.6 LAE sample by a factor of five and tighten these\nlimits. If the clustering signature of reionization is detected in a LAE\nsurvey, a comparison with a Lyman-break or a H-alpha survey in the same field\nwould confirm the reionization hypothesis. We discuss the optimal LAE survey\nspecifications for detecting reionization, with reference to upcoming programs.", "Bose-Einstein condensation has been achieved in a magnetically trapped sample\nof 85Rb atoms. Long-lived condensates of up to 10^4 atoms have been produced by\nusing a magnetic-field-induced Feshbach resonance to reverse the sign of the\nscattering length. This system provides many unique opportunities for the study\nof condensate physics. The variation of the scattering length near the\nresonance has been used to magnetically tune the condensate self-interaction\nenergy over a very wide range. This range extended from very strong repulsive\nto large attractive self-interactions. When the interactions were switched from\nrepulsive to attractive, the condensate shrank to below our resolution limit,\nand after ~5 ms emitted a burst of high-energy atoms.", "We study how rotation affects observable amplitudes of high-order g- and\nmixed r/g-modes and examine prospects for their detection and identification.\nOur formalism, which is described in some detail, relies on a nonadiabatic\ngeneralization of the traditional approximation. Numerical results are\npresented for a number of unstable modes in a model of SPB star, at rotation\nrates up to 250 km/s. It is shown that rotation has a large effect on mode\nvisibility in light and in mean radial velocity variations. In most cases, fast\nrotation impairs mode detectability of g-modes in light variation, as Townsend\n(2003b) has already noted, but it helps detection in radial velocity variation.\nThe mixed modes, which exist only at sufficiently fast rotation, are also more\neasily seen in radial velocity. The amplitude ratios and phase differences are\nstrongly dependent on the aspect, the rotational velocity and on the mode. The\nlatter dependence is essential for mode identification.", "Within a theoretical model based on the Boltzmann equation, we analyze in\ndetail the structure of the unusual peak recently observed in the relaxation\ntime in Cu. In particular, we discuss the role of Auger electrons in the\nelectron dynamics and its dependence on the d-hole lifetime, the optical\ntransition matrix elements and the laser pulse duration. We find that the Auger\ncontribution to the distribution is very sensitive to both the d-hole lifetime\ntau_h and the laser pulse duration tau_l and can be expressed as a monotonic\nfunction of tau_l/tau_h. We have found that for a given tau_h, the Auger\ncontribution is significantly smaller for a short pulse duration than for a\nlonger one. We show that the relaxation time at the peak depends linearly on\nthe d-hole lifetime, but interestingly not on the amount of Auger electrons\ngenerated. We provide a simple expression for the relaxation time of excited\nelectrons which shows that its shape can be understood by a phase space\nargument and its amplitude is governed by the d-hole lifetime. We also find\nthat the height of the peak depends on both the ratio of the optical transition\nmatrix elements R=|M_{d \\to sp}|^2/|M_{sp \\to sp}|^2 and the laser pulse\nduration. Assuming a reasonable value for the ratio, namely R = 2, and a d-hole\nlifetime of tau_h=35 fs, we obtain for the calculated height of the peak Delta\ntau_{th}=14 fs, in fair agreement with Delta tau_{exp} \\approx 17 fs measured\nfor polycrystalline Cu.", "We present absorption line strength maps of a sample of 24 representative\nearly-type spiral galaxies, mostly of type Sa, obtained as part of the SAURON\nsurvey of nearby galaxies using our custom-built integral-field spectrograph.\nUsing high-quality spectra, spatially binned to a constant signal-to-noise, we\nmeasure several key age, metallicity and abundance ratio sensitive indices from\nthe Lick/IDS system over a contiguous two-dimensional field including bulge and\ninner disc. We present maps of H beta, Fe 5015 and Mg b, for each galaxy\n  The absorption line maps show that many galaxies contain some younger\npopulations (<= 1 Gyr), distributed in small or large inner discs, or in\ncircumnuclear star forming rings. In many cases these young stars are formed in\ncircumnuclear mini-starbursts, which are dominating the light in the centres of\nsome of the early-type spirals. These mini-starburst cause a considerable\nscatter in index-index diagrams such as Mg b- H beta and Mg b -Fe 5015, more\nthan is measured for early-type galaxies. We find that the central regions of\nSa galaxies display a wide range in ages, even within the galaxies. 50% of the\nsample show velocity dispersion drops in their centres.\n  All of the galaxies of our sample lie on or below the Mg b- $\\sigma$ relation\nfor elliptical galaxies in the Coma cluster, and above the H beta absorption\nline - $\\sigma$ relation for elliptical galaxies. If those relations are\nconsidered to be relations for the oldest local galaxies we see that our sample\nof spirals has a considerable scatter in age, with the largest scatter at the\nlowest $\\sigma$. This is in disagreement with highly inclined samples, in which\ngenerally only old stellar populations are found in the central regions.\n  All this can be understood if ... (see paper for rest of abstract)", "We compute an approximate set of longitudinal quasiparticle modes for a\nhydrogen condensate as produced in the MIT experiments. An expansion in\nquasiparticles using a simple one-dimensional Bogoliubov picture shows however\nthat at the high temperatures (\\approx 44muK) and in the very shallow trap\nemployed (omega_z = 2\\pi\\times 10.2Hz) the contribution to the density from the\nquasiparticles is about 20% of that from the condensate mode, leading to an\neffective $ g_2(x,x) which varies between 1 and 3 depending on the position in\nthe condensate.", "Impedance measurements provide a useful probe of the physics of bolometers\nand calorimeters. We describe a method for measuring the complex impedance of\nthese devices. In previous work, stray impedances and readout electronics of\nthe measurement apparatus have resulted in artifacts in the impedance data. The\nnew technique allows experimenters to find an independent Thevenin or Norton\nequivalent circuit for each frequency. This method allows experimenters to\neasily isolate the device impedance from the effects of parasitic impedances\nand frequency dependent gains in amplifiers.", "We derive masses and radii for both components in the single-lined eclipsing\nbinary HAT-TR-205-013, which consists of a F7V primary and a late M-dwarf\nsecondary. The system's period is short, $P=2.230736 \\pm 0.000010$ days, with\nan orbit indistinguishable from circular, $e=0.012 \\pm 0.021$. We demonstrate\ngenerally that the surface gravity of the secondary star in a single-lined\nbinary undergoing total eclipses can be derived from characteristics of the\nlight curve and spectroscopic orbit. This constrains the secondary to a unique\nline in the mass-radius diagram with $M/R^2$ = constant. For HAT-TR-205-013, we\nassume the orbit has been tidally circularized, and that the primary's rotation\nhas been synchronized and aligned with the orbital axis. Our observed line\nbroadening, $V_{\\rm rot} \\sin i_{\\rm rot} = 28.9 \\pm 1.0$ \\kms, gives a primary\nradius of $R_{\\rm A} = 1.28 \\pm 0.04$ \\rsun. Our light curve analysis leads to\nthe radius of the secondary, $R_{\\rm B} = 0.167 \\pm 0.006$ \\rsun, and the\nsemimajor axis of the orbit, $a = 7.54 \\pm 0.30 \\rsun = 0.0351 \\pm 0.0014$ AU.\nOur single-lined spectroscopic orbit and the semimajor axis then yield the\nindividual masses, $M_{\\rm B} = 0.124 \\pm 0.010$ \\msun and $M_{\\rm A} = 1.04\n\\pm 0.13$ \\msun. Our result for HAT-TR-205-013 B lies above the theoretical\nmass-radius models from the Lyon group, consistent with results from\ndouble-lined eclipsing binaries. The method we describe offers the opportunity\nto study the very low end of the stellar mass-radius relation.", "Through an extensive numerical study, we find that the low-lying,\nquasi-degenerate eigenenergies of weakly-interacting trapped N bosons with\ntotal angular momentum L are given in case of small L/N and sufficiently small\nL by E = L hbar omega + g[N(N-L/2-1)+1.59 n(n-1)/2], where omega is the\nfrequency of the trapping potential and g is the strength of the repulsive\ncontact interaction; the last term arises from the pairwise repulsive\ninteraction among n octupole excitations and describes the lowest-lying\nexcitation spectra from the Yrast line. In this case, the quadrupole modes do\nnot interact with themselves and, together with the octupole modes, exhaust the\nlow-lying spectra which are separated from others by N-linear energy gaps.", "A system of a metastable phase with several sorts of the heterogeneous\ncenters is considered. An analytical theory for the process of decay in such a\nsystem has been constructed. The free energy of formation of the critical\nembryo is assumed to be known in the macroscopic approach as well as the energy\nof solvatation. The process is split into some periods and the analytical\ndescription of every period is given. The most difficult to describe is the\nperiod of the essential formation of the embryos of a new phase. At first some\nasymptotes are investigated and then a general solution is suggested. Several\napproximate transformations are accomplished with the corresponding numerical\nestimates and some analytical justifications.", "The photospheres of stars hosting planets have larger metallicity than stars\nlacking planets. In the present work we study the possibility of an earlier\nmetal enrichment of the photospheres by means of impacting planetesimals during\nthe first 20-30Myr. Here we explore this contamination process by simulating\nthe interactions of an inward migrating planet with a disc of planetesimal\ninterior to its orbit. The results show the percentage of planetesimals that\nfall on the star. We identified the dependence of the planet's eccentricity\n($e_p$) and time scale of migration ($\\tau$) on the rate of infalling\nplanetesimals. For very fast migrations ($\\tau=10^2$yr and $\\tau=10^3$yr) there\nis no capture in mean motion resonances, independently of the value of $e_p$.\nThen, due to the planet's migration the planetesimals suffer close approaches\nwith the planet and more than 80% of them are ejected from the system. For slow\nmigrations ($\\tau=10^5$yr and $\\tau=10^6$yr) the percentage of collisions with\nthe planet decrease with the increase of the planet's eccentricity. For $e_p=0$\nand $e_p=0.1$ most of the planetesimals were captured in the 2:1 resonance and\nmore than 65% of them collided with the star. Whereas migration of a Jupiter\nmass planet to very short pericentric distances requires unrealistic high disc\nmasses, these requirements are much smaller for smaller migrating planets. Our\nsimulations for a slowly migrating 0.1 $M_{\\rm Jupiter}$ planet, even demanding\na possible primitive disc three times more massive than a primitive solar\nnebula, produces maximum [Fe/H] enrichments of the order of 0.18 dex. These\ncalculations open possibilities to explain hot Jupiters exoplanets\nmetallicities.", "Interpretation of experiments on quantum dot (QD) lasers presents a\nchallenge: the phonon bottleneck, which should strongly suppress relaxation and\ndephasing of the discrete energy states, often seems to be inoperative. We\nsuggest and develop a theory for an intrinsic mechanism for dephasing in QD's:\nsecond-order elastic interaction between quantum dot charge carriers and\nLO-phonons. The calculated dephasing times are of the order of 200 fs at room\ntemperature, consistent with experiments. The phonon bottleneck thus does not\nprevent significant room temperature dephasing.", "A probability distribution function is presented which provides a realistic\ndescription of the detection of scattered photons. The resulting probabilities\ncan be described analytically by means of a superposition of several special\nfunctions. These exact expressions can be evaluated numerically only for small\ndistances and limited time residuals, due to computer accuracy limitations. In\nthis report we provide approximations for the exact expressions in different\nregions of the distance-time residual space, defined by the detector geometry\nand the space-time scale of an event. These approximations can be evaluated\nnumerically with a relative error with respect to the exact expression at the\nboundaries of less than 0.001.", "The six-vertex model with domain wall boundary conditions is considered. A\nFredholm determinant representation for the partition function of the model is\nobtained. The kernel of the corrtesponding integral operator depends on\nLaguerre polynomials.", "The reverse shock of supernova remnant (SNR) 1987A emits in H-alpha and\nLy-alpha, and comes in two flavors: surface and interior. The former is due to\ndirect, impact excitation of hydrogen atoms crossing the shock, while the\nlatter is the result of charge transfer reactions between these atoms and\nslower, post-shock ions. Interior and surface emission are analogous to the\nbroad- and narrow-line components observed in Balmer-dominated SNRs. I\nsummarize a formalism to derive line intensities and ratios in these SNRs, as\nwell as a study of the transition zone in supernova shocks; I include an\nappendix where I derive in detail the ratio of broad to narrow H-alpha\nemission. Further study of the reverse shock emission from SNR 1987A will allow\nus to predict when it will vanish and further investigate the origins of the\ninterior emission.", "The idea that substantial absorption in AGN could be a definite\ncharacteristic of the early phases of QSO evolution was invoked to explain the\nsubmillimeter observations of X-ray absorbed AGN at z~1 to z~3, that have shown\nstrong emission at 850 mkm. This strong emission is a signature of the copious\nstar formation. In AGN evolution model, the main obscured growth phase of the\nQSO coincides with formation of the host galaxy spheroid, the completion of\nwhich indicates the beginning of the luminous, unobscured phase of the QSO's\nevolution. The verification of this model at redshifts up to z~6 appears\npossible via application of the gamma-ray resonant absorption method.", "The influence of a non-magnetic metallic substrate on the spin wave\nexcitations in ultrathin ferromagnetic overlayers is investigated for different\ncrystalline orientations. We show that spin wave dumping in these systems occur\ndue to the tunneling of holes from the substrate into the overlayer, and that\nthe spin wave energies may be considerably affected by the exchange coupling\nmediated by the substrate.", "The tensor-virial method is applied for a study of oscillation modes of\nuniformly rotating Bose-Einstein condensed gases, whose rigid body rotation is\nsupported by an vortex array. The second order virial equations are derived in\nthe hydrodynamic regime for an arbitrary external harmonic trapping potential\nassuming that the condensate is a superfluid at zero temperature. The\naxisymmetric equilibrium shape of the condensate is determined as a function of\nthe deformation of the trap; its domain of stability is bounded by the\nconstraint $\\Omega<1$ on the rotation rate (measured in units of the trap\nfrequency $\\omega_0$.) The oscillations of the axisymmetric condensate are\nstable with respect to the transverse-shear, toroidal and quasi-radial modes of\noscillations, corresponding to the $l= 2$, $| m| = 0,1,2 $ surface\ndeformations. In non-axisymmetric traps, the equilibrium constrains the\n(dimensionless) deformation in the plane orthogonal to the rotation to the\ndomain $A_2 > \\Omega^2$ with $\\Omega< 1$. The second harmonic oscillation modes\nin non-axisymmetric traps separate into two classes which have even or odd\nparity with respect to the direction of the rotation axis. Numerical solutions\nshow that these modes are stable in the parameter domain where equilibrium\nfigures exist.", "Magneto infra-red absorption measurements have been performed in a highly\ndoped GaAs quantum well which has been lifted off and bonded to a silicon\nsubstrate, in order to study the resonant polaron interaction. It is found that\nthe pinning of the cyclotron energy occurs at an energy close to that of the\ntransverse optical phonon of GaAs. This unexpected result is explained by a\nmodel taking into account the full dielectric constant of the quantum well.", "Cornell University, the California Institute for Technology, and the Jet\nPropulsion Laboratory are jointly studying the construction of a 25 m diameter\ntelescope for submillimeter astronomy on a high mountain in northern Chile.\nThis Cornell Caltech Atacama Telescope (CCAT) will combine high sensitivity, a\nwide field of view, and a broad wavelength range to provide an unprecedented\ncapability for deep, large area, multi-color submillimeter surveys to\ncomplement narrow field, high resolution studies with ALMA. CCAT observations\nwill address fundamental themes in contemporary astronomy, notably the\nformation and evolution of galaxies, the nature of the dark matter and dark\nenergy that comprise most of the content of the universe, the formation of\nstars and planets, the conditions in circumstellar disks, and the conditions\nduring the early history of the Solar system. The candidate CCAT site, at 5600\nm in northern Chile, enjoys superb observing conditions. To accommodate large\nformat bolometer cameras, CCAT is designed with a 20 arcmin field of view. CCAT\nwill incorporate closed loop active control of its segmented primary mirror to\nmaintain a half wavefront error of 10 mum rms or less. Instrumentation under\nconsideration includes both short (650 mum-200 mum) and long (2 mm-750 mum)\nwavelength bolometer cameras, direct detection spectrometers, and heterodyne\nreceiver arrays. The University of Colorado, a Canadian university consortium,\nand the UK Astronomy Technology Centre on behalf of the UK community are\npursuing participation in the CCAT consortium. When complete early in the next\ndecade, CCAT will be the largest and most sensitive facility of its class as\nwell as the highest altitude astronomical facility on Earth.", "For optimally doped Bi 2212, scattering rates in the normal state are found\nto have a linear temperature dependence over most of the Fermi surface. In the\nimmediate vicinity of the (1,0) point, the scattering rates are nearly constant\nin the normal state, consistent with models in which scattering at this point\ndetermines the c-axis transport. In the superconducting state, the scattering\nrates away from the nodal direction appear to level off and become\ntemperature-independent.", "A cluster algorithm is presented for the simulation of the q-state Potts\nmodels in which the number of spins is conserved in each state. The algorithm\nconstructs Fortuin-Kasteleyn cluster configurations from spin configurations,\nin a way identical to the Swendsen-Wang algorithm; the spin assignment to these\nclusters is however different, and conserves the number of spins for each\nstate. Compared to traditional non-local spin-exchange algorithms, the cluster\nalgorithm presented here suffers less from critical slowing down, and\nconsequently is more efficient near the critical temperature.", "The bipolar HH 212 outflow has been mapped in SiO using the extended\nconfiguration of the Plateau de Bure Interferometer (PdBI), revealing a highly\ncollimated SiO jet closely associated with the H2 jet component. We study at\nunprecedented resolution (0.34\" across the jet axis) the properties of the\ninnermost SiO ``microjet'' within 1000 AU of this young Class 0 source, to\ncompare it with atomic microjets from more evolved sources and to constrain its\norigin. The SiO channel maps are used to investigate the microjet collimation\nand velocity structure. A large velocity gradient analysis is applied to SiO\n(2-1), (5-4) and (8-7) data from the PdBI and the Submillimeter Array to\nconstrain the SiO opacity and abundance. The HH212 Class 0 microjet shows\nstriking similarities in collimation and energetic budget with atomic microjets\nfrom T Tauri sources. Furthermore, the SiO lines appear optically thick, unlike\nwhat is generally assumed. We infer T(kin) ~ 50-500 K and an SiO/H2 abundance\ngreater than 4 10(-8)-6 10(-5) for n(H2) = 10(7)-10(5) cm(-3), i.e. 0.05-90% of\nthe elemental silicon. This similar jet width, regardless of the presence of a\ndense envelope, definitely rules out jet collimation by external pressure, and\nfavors a common MHD self-collimation (and possibly acceleration) process at all\nstages of star formation. We propose that the more abundant SiO in Class 0 jets\ncould mainly result from rapid (less than 25 yrs) molecular synthesis at high\njet densities.", "The magnetic behavior of a mixed Ising ferrimagnetic system on a square\nlattice, in which the two interpenetrating square sublattices have spins +- 1/2\nand spins +-1,0, in the presence of an oscillating magnetic field has been\nstudied with Monte Carlo techniques. The model includes nearest and\nnext-nearest neighbor interactions, a crystal field and the oscillating\nexternal field. By studying the hysteretic response of this model to an\noscillating field we found that it qualitatively reproduces the increasing of\nthe coercive field at the compensation temperature observed in real\nferrimagnets, a crucial feature for magneto-optical applications. This behavior\nis basically independent of the frequency of the field and the size of the\nsystem. The magnetic response of the system is related to a dynamical\ntransition from a paramagnetic to a ferromagnetic phase and to the different\ntemperature dependence of the relaxation times of both sublattices.", "The effect of an exchange field on electrical transport in thin films of\nmetallic ferromagnetic manganites has been investigated. The exchange field was\ninduced both by direct exchange coupling in a ferromagnet/antiferromagnet\nmultilayer and by indirect exchange interaction in a ferromagnet/paramagnet\nsuperlattice. The electrical resistance of the manganite layers was found to be\ndetermined by the absolute value of the vector sum of the effective exchange\nfield and the external magnetic field.", "In a recent Letter Hammar et al. claim the observation of injection of a\nspin-polarized current in a two-dimensional electron gas (2DEG). This is an\nimportant observation, since, despite considerable effort of several groups,\nall attempts to realize spin-injection into a 2DEG using purely electrical\nmeasurements have failed sofar. However, in my opinion the claim made is not\ncorrect, and the observed behaviour can be explained by a combination of a\nmagneto resistance (Hall) effect (e.g. generated by the fringe magnetic fields\npresent at the edges of the ferromagnetic electrode), with a {\\it\nspin-independent} rectification effect due to the presence of a metal-\nsemiconductor junction.", "Consider a time-dependent Hamiltonian $H(Q,P;x(t))$ with periodic driving\n$x(t)=A\\sin(\\Omega t)$. It is assumed that the classical dynamics is chaotic,\nand that its power-spectrum extends over some frequency range\n$|\\omega|<\\omega_{cl}$. Both classical and quantum-mechanical (QM) linear\nresponse theory (LRT) predict a relatively large response for\n$\\Omega<\\omega_{cl}$, and a relatively small response otherwise, independently\nof the driving amplitude $A$. We define a non-perturbative regime in the\n$(\\Omega,A)$ space, where LRT fails, and demonstrate this failure numerically.\nFor $A>A_{prt}$, where $A_{prt}\\propto\\hbar$, the system may have a relatively\nstrong response for $\\Omega>\\omega_{cl}$, and the shape of the response\nfunction becomes $A$ dependent.", "We study the sodium D lines (D1: 5895.92 \\AA; D2: 5889.95 \\AA) in late-type\ndwarf stars. The stars have spectral types between F6 and M5.5 (B-V between\n0.457 and 1.807) and metallicity between [Fe/H] = -0.82 and 0.6. We obtained\nmedium resolution echelle spectra using the 2.15-m telescope at the argentinian\nobservatory CASLEO. The observations have been performed periodically since\n1999. The spectra were calibrated in wavelength and in flux. A definition of\nthe pseudo-continuum level is found for all our observations. We also define a\ncontinuum level for calibration purposes. The equivalent width of the D lines\nis computed in detail for all our spectra and related to the colour index (B-V)\nof the stars. When possible, we perform a careful comparison with previous\nstudies. Finally, we construct a spectral index (R_D') as the ratio between the\nflux in the D lines, and the bolometric flux. We find that, once corrected for\nthe photospheric contribution, this index can be used as a chromospheric\nactivity indicator in stars with a high level of activity. Additionally, we\nfind that combining some of our results, we obtain a method to calibrate in\nflux stars of unknown colour.", "We consider a Fermi gas confined by a harmonic trapping potential and we\nhighlight the role of the Fermi-Dirac statistics by studying frequency and\ndamping of collective oscillations of quadrupole type in the framework of the\nquantum Boltzmann equation, in which statistical corrections are taken into\naccount in the collisional integral. We are able to describe the crossover from\nthe collisionless regime to the hydrodynamic one by introducing a\ntemperature-dependent relaxation time $\\tau_Q$. We show that, in the degenerate\nregime, the relaxation rate $1/\\tau_Q$ exhibits a temperature dependence\ndifferent from the collision rate $\\gamma$. We finally compare the collisional\nproperties of the Fermi gas with the ones of the Bose gas for temperatures\nabove the Bose-Einstein condensation.", "In the weak backscattering limit, point contact tunneling between quantum\nHall edges is well described by a Poissonian process where Laughlin\nquasiparticles tunnel independently, leading to the unambiguous measurement of\ntheir fractional charges. In the strong backscattering limit, the tunneling is\nwell described by a Poissonian process again, but this time involving real\nelectrons. In between, interactions create essential correlations, which we\nuntangle exactly in this Letter. Our main result is an exact closed form\nexpression for the probability distribution of the charge $N(t)$ that tunnels\nin the time interval $t$. Formally, this distribution corresponds to a sum of\nindependent Poisson processes carrying charge $\\nu e$, $2\\nu e$, etc., or,\nafter resummation, processes carrying charge $e$, $2e$, etc. In the course of\nthe proof, we compare the integrable and Keldysh approaches, and find, as a\nresult of spectacular cancellations between perturbative integrals, the\nexpected agreement.", "We present results from a high-angular-resolution survey of 78 very low mass\n(VLM) binary systems with 6.0 <= V-K colour <= 7.5 and proper motion >= 0.15\narcsec/yr. 21 VLM binaries were detected, 13 of them new discoveries. The new\nbinary systems range in separation between 0.18 arcsec and 1.3 arcsec. The\ndistance-corrected binary fraction is 13.5% (+6.5%/-4%), in agreement with\nprevious results. 9 of the new binary systems have orbital radii > 10 AU,\nincluding a new wide VLM binary with 27 AU projected orbital separation. One of\nthe new systems forms two components of a 2300 AU separation triple system. We\nfind that the orbital radius distribution of the binaries with V-K < 6.5 in\nthis survey appears to be different from that of redder (lower-mass) objects,\nsuggesting a possible rapid change in the orbital radius distribution at around\nthe M5 spectral type. The target sample was also selected to investigate X-ray\nactivity among VLM binaries. There is no detectable correlation between excess\nX-Ray emission and the frequency and binary properties of the VLM systems.", "This review covers selected developments in maser theory since the previous\nmeeting, \"Cosmic Masers: From Proto-Stars to Black Holes\" (Migenes & Reid\n2002). Topics included are time variability of fundamental constants, pumping\nof OH megamasers and indicators for differentiating disks from bi-directional\noutflows.", "We present observations of a solar quiet region obtained by the ground-based\nDutch Open Telescope (DOT), and by instruments on the spacecraft SOHO and\nTRACE. The observations were obtained during a coordinated observing campaign\non October 2005. The aim of this work is to present the rich diversity of\nfine-scale structures that are found at the network boundaries and their\nappearance in different instruments and different spectral lines that span the\nphotosphere to the corona. Detailed studies of these structures are crucial to\nunderstanding their dynamics in different solar layers, as well as the role\nsuch structures play in the mass balance and heating of the solar atmosphere.", "The superfluidity of Bose-Einstein condensates in optical lattices are\ninvestigated. Apart from the usual Landau instability which occurs when a BEC\nflows faster than the speed of sound, the BEC can also suffer a dynamical\ninstability, resulting in period doubling and other sorts of symmetry breaking\nof the system. Such an instability may play a crucial role in the dissipative\nmotion of a trapped BEC in an optical lattice recently observed [1].", "We discuss the link between uncorrelated noise and Hurst exponent for one and\ntwo-dimensional interfaces. We show that long range correlations cannot be\nobserved using one-dimensional cuts through two-dimensional self-affine\nsurfaces whose height distributions are characterized by a Hurst exponent lower\nthan -1/2. In this domain, fractional and white noise are not distinguishable.\nA method analysing the correlations in two dimensions is necessary. For Hurst\nexponents larger than -1/2, a crossover regime leads to a systematic over\nestimate of the Hurst exponent.", "We analyzed voltage rectification for dc SQUIDs biased with ac current with\nzero mean value. We demonstrate that the reflection symmetry in the\n2-dimensional SQUID potential is broken by an applied flux and with appropriate\nasymmetries in the dc SQUID. Depending on the type of asymmetry, we obtain a\nrocking or a simultaneously rocking and flashing ratchet, the latter showing\nmultiple sign reversals in the mean voltage with increasing amplitude of the ac\ncurrent. Our experimental results are in agreement with numerical solutions of\nthe Langevin equations for the asymmetric dc SQUID.", "A model for diffusion on a cubic lattice with a random distribution of traps\nis developed. The traps are redistributed at certain time intervals. Such\nmodels are useful for describing systems showing dynamic disorder, such as\nion-conducting polymers. In the present model the traps are infinite, unlike an\nearlier version with finite traps, this model has a percolation threshold. For\nthe infinite trap version a simple analytical calculation is possible and the\nresults agree qualitatively with simulation.", "We present the results of the analysis of an archival 15 ks XMM-Newton\nobservation of the nearby (z=0.057) radio-loud source 3C445, optically\nclassified as a Broad-Line Radio Galaxy. While the RGS data are of insufficient\nquality to allow a meaningful analysis, the EPIC data show a remarkable X-ray\nspectrum. The 2-10 keV continuum is described by a heavily absorbed (Nh~ 1e22 -\n1e23 cm-2) power law with photon index Gamma ~1.4, and strong (R~2) cold\nreflection. A narrow, unresolved Fe Kalpha emission line is detected,\nconfirming previous findings, with EW 120eV. A soft excess is present below 2\nkeV over the extrapolation of the hard X-ray power law, which we model with a\npower law with the same photon index as the hard power law, absorbed by a\ncolumn density Nh=6e20 cm-2 in excess to Galactic. A host of emission lines are\npresent below 2 keV, confirming previous indications from ASCA, due to H- and\nHe-like O, Mg, and Si. We attribute the origin of the lines to a photoionized\ngas, with properties very similar to radio-quiet obscured AGN. Two different\nionized media, or a single stratified medium, are required to fit the soft\nX-ray data satisfactorily. The similarity of the X-ray spectrum of 3C445 to\nSeyferts underscores that the central engines of radio-loud and radio-quiet AGN\nsimilarly host both cold and warm gas.", "To provide criteria in the selection of target events preferable for\nplanetary lensing follow-up observations, we investigate the variation of the\nprobability of detecting planetary signals depending on the observables of the\nlensing magnification and source brightness. In estimating the probability, we\nconsider variation of the photometric precision by using a quantity defined as\nthe ratio of the fractional deviation of the planetary perturbation to the\nphotometric precision. From this investigation, we find consistent result from\nprevious studies that the probability increases with the increase of the\nmagnification. The increase rate is boosted at a certain magnification at which\nperturbations caused by central caustic begin to occur. We find this boost\noccurs at moderate magnifications of $A\\lesssim 20$, implying that probability\ncan be high even for events with moderate magnifications. The probability\nincreases as the source brightness increases. We find that the probability of\nevents associated with stars brighter than clump giants is not negligible even\nat magnifications as low as $A\\sim 5$. In the absence of rare the prime target\nof very high-magnification events, we, therefore, recommend to observe events\nwith brightest source stars and highest magnifications among the alerted\nevents. Due to the increase of the source size with the increase of the\nbrightness, however, the probability rapidly drops off beyond a certain\nmagnification, causing detections of low mass ratio planets ($q\\lesssim\n10^{-4}$) difficult from the observations of events involved with giant stars\nwith magnifications $A\\gtrsim 70$.", "We present new results from our ongoing multiplicity study of exoplanet host\nstars, carried out with the infrared camera SofI at ESO-NTT. We have identified\nnew low mass companions to the planet host stars HD101930 and HD65216.\nHD101930AB is a wide binary systems composed of the planet host star HD101930A\nand its companion HD101930B which is a M0 to M1 dwarf with a mass of about\n0.7Msun separated from the primary by ~73arcsec (2200AU projected separation).\nHD65216 forms a hierarchical triple system, with a projected separation of\n253AU (angular separation of about 7arcsec) between the planet host star\nHD65216A and its close binary companion HD65216BC, whose two components are\nseparated by only ~0.17arcsec (6AU of projected separation). Two VLT-NACO\nimages separated by 3 years confirm that this system is co-moving to the planet\nhost star. The infrared photometry of HD65216B and C is consistent with a M7 to\nM8 (0.089Msun), and a L2 to L3 dwarf (0.078Msun), respectively, both close to\nthe sub-stellar limit. An infrared spectrum with VLT-ISAAC of the pair\nHD65216BC, even though not resolved spatially, confirms this late spectral\ntype. Furthermore, we present H- and K-band ISAAC infrared spectra of HD16141B,\nthe recently detected co-moving companion of the planet host star HD16141A. The\ninfrared spectroscopy as well as the apparent infrared photometry of HD16141B\nare both fully consistent with a M2 to M3 dwarf located at the distance of the\nplanet host star.", "As soon as one accepts to abandon the zero-risk paradigm of Black-Scholes,\nvery interesting issues concerning risk control arise because different\ndefinitions of the risk become unequivalent. Optimal hedges then depend on the\nquantity one wishes to minimize. We show that a definition of the risk more\nsensitive to the extreme events generically leads to a decrease both of the\nprobability of extreme losses and of the sensitivity of the hedge on the price\nof the underlying (the `Gamma'). Therefore, the transaction costs and the\nimpact of hedging on the price dynamics of the underlying are reduced.", "We present 0.8 to 2.4 micron spectral observations of uranian satellites,\nobtained at IRTF/SpeX on 17 nights during 2001-2005. The spectra reveal for the\nfirst time the presence of CO2 ice on the surfaces of Umbriel and Titania, by\nmeans of 3 narrow absorption bands near 2 microns. Several additional, weaker\nCO2 ice absorptions have also been detected. No CO2 absorption is seen in\nOberon spectra, and the strengths of the CO2 ice bands decline with\nplanetocentric distance from Ariel through Titania. We use the CO2 absorptions\nto map the longitudinal distribution of CO2 ice on Ariel, Umbriel, and Titania,\nshowing that it is most abundant on their trailing hemispheres. We also examine\nH2O ice absorptions in the spectra, finding deeper H2O bands on the leading\nhemispheres of Ariel, Umbriel, and Titania, but the opposite pattern on Oberon.\nPotential mechanisms to produce the observed longitudinal and planetocentric\ndistributions of the two ices are considered.", "The zero temperature Hall constant R_H, described by reactive\n(nondissipative) conductivities, is analyzed within linear response theory. It\nis found that in a certain limit, R_H is directly related to the density\ndependence of the Drude weight implying a simple picture for the change of sign\nof charge carriers in the vicinity of a Mott-Hubbard transition. This novel\nformulation is applied to the calculation of R_H in quasi-one dimensional and\nladder prototype interacting electron systems.", "We calculate the frequencies and damping rates of the low-lying collective\nmodes of a Bose-Einstein condensed gas at nonzero temperature. We use a complex\nnonlinear Schr\\\"odinger equation to determine the dynamics of the condensate\natoms, and couple it to a Boltzmann equation for the noncondensate atoms. In\nthis manner we take into account both collisions between\nnoncondensate-noncondensate and condensate-noncondensate atoms. We solve the\nlinear response of these equations, using a time-dependent gaussian trial\nfunction for the condensate wave function and a truncated power expansion for\nthe deviation function of the thermal cloud. As a result, our calculation turns\nout to be characterized by two dimensionless parameters proportional to the\nnoncondensate-noncondensate and condensate-noncondensate mean collision times.\nWe find in general quite good agreement with experiment, both for the\nfrequencies and damping of the collective modes.", "We discuss phenomenon of simultaneous presence of O- and C-based material in\nsurroundings of evolutionary advanced stars. We concentrate on silicate carbon\nstars and present observations that directly confirm the binary model scenario\nfor them. We discuss also class of C-stars with OH emission detected, to which\nsome [WR] planetary nebulae do belong.", "We apply path integration techniques to obtain option pricing with stochastic\nvolatility using a generalized Black-Scholes equation known as the Merton and\nGarman equation. We numerically simulate the option prices using the technique\nof path integration. Using market data, we determine the parameters of the\nmodel. It is found that the market chooses a special class of models for which\na more efficient algorithm, called the bisection method, is applicable. Using\nour simulated data, we generate some implied volatility curves. We also analyze\nand study in detail some of the characteristics of the volatility curves within\nthe model.", "Context. One of the typical features shown by observations of solar\nprominence oscillations is that they are damped in time and that the values of\nthe damping times are usually between one and three times the corresponding\noscillatory period. However, the mechanism responsible for the attenuation is\nstill not well-known. Aims. Thermal conduction, optically thin or thick\nradiation and heating are taken into account in the energy equation, and their\nrole on the attenuation of prominence oscillations is evaluated. Methods. The\ndispersion relation for linear non-adiabatic magnetoacoustic waves is derived\nconsidering an equilibrium made of a prominence plasma slab embedded in an\nunbounded corona. The magnetic field is orientated along the direction parallel\nto the slab axis and has the same strength in all regions. By solving the\ndispersion relation for a fixed wavenumber, a complex oscillatory frequency is\nobtained, and the period and the damping time are computed. Results. The effect\nof conduction and radiation losses is different for each magnetoacoustic mode\nand depends on the wavenumber. In the observed range of wavelengths the\ninternal slow mode is attenuated by radiation from the prominence plasma, the\nfast mode by the combination of prominence radiation and coronal conduction and\nthe external slow mode by coronal conduction. The consideration of the external\ncorona is of paramount importance in the case of the fast and external slow\nmodes, whereas it does not affect the internal slow modes at all. Conclusions.\nNon-adiabatic effects are efficient damping mechanisms for magnetoacoustic\nmodes, and the values of the obtained damping times are compatible with those\nobserved.", "The discovery of the superfluid phases of Helium 3 in 1971 opened the door to\none of the most fascinating systems known in condensed matter physics.\nSuperfluidity of Helium 3, originating from pair condensation of Helium 3\natoms, turned out to be the ideal testground for many fundamental concepts of\nmodern physics, such as macroscopic quantum phenomena, (gauge-)symmetries and\ntheir spontaneous breakdown, topological defects, etc. Thereby the superfluid\nphases of Helium 3 enriched condensed matter physics enormously. In particular,\nthey contributed significantly - and continue to do so - to our understanding\nof various other physical systems, from heavy fermion and high-Tc\nsuperconductors all the way to neutron stars, particle physics, gravity and the\nearly universe. A simple introduction into the basic concepts and questions is\npresented.", "We test the gamma-ray burst correlation between temporal variability and peak\nluminosity of the $\\gamma$-ray profile on a homogeneous sample of 36 Swift/BAT\nGRBs with firm redshift determination. This is the first time that this\ncorrelation can be tested on a homogeneous data sample. The correlation is\nconfirmed, as long as the 6 GRBs with low luminosity (<5x10^{50} erg s^{-1} in\nthe rest-frame 100-1000 keV energy band) are ignored. We confirm that the\nconsiderable scatter of the correlation already known is not due to the\ncombination of data from different instruments with different energy bands, but\nit is intrinsic to the correlation itself. Thanks to the unprecedented\nsensitivity of Swift/BAT, the variability/peak luminosity correlation is tested\non low-luminosity GRBs. Our results show that these GRBs are definite outliers.", "The extraordinary astrometric accuracy of radio interferometry creates an\nimportant and unique opportunity for the discovery and characterization of\nexo-planets. Currently, the Very Long Baseline Array can routinely achieve\nbetter than 100 microarcsecond accuracy, and can approach 10 microarcsecond\nwith careful calibration. We describe here RIPL, the Radio Interferometric\nPLanet search, a new program with the VLBA and the Green Bank 100 m telescope\nthat will survey 29 low-mass, active stars over 3 years with sub-Jovian planet\nmass sensitivity at 1 AU. An upgrade of the VLBA bandwidth will increase\nastrometric accuracy by an order of magnitude. Ultimately, the colossal\ncollecting area of the Square Kilometer Array could push astrometric accuracy\nto 1 microarcsecond, making detection and characterizaiton of Earth mass\nplanets possible.\n  RIPL and other future radio astrometric planet searches occupy a unique\nvolume in planet discovery and characterization parameter space. The parameter\nspace of astrometric searches gives greater sensitivity to planets at large\nradii than radial velocity searches. For the VLBA and the expanded VLBA, the\ntargets of radio astrometric surveys are by necessity nearby, low-mass, active\nstars, which cannot be studied efficiently through the radial velocity method,\ncoronagraphy, or optical interferometry. For the SKA, detection sensitivity\nwill extend to solar-type stars. Planets discovered through radio astrometric\nmethods will be suitable for characterization through extreme adaptive optics.\n  The complementarity of radio astrometric techniques with other methods\ndemonstrates that radio astrometry can play an important role in the roadmap\nfor exoplanet discovery and characterization.", "The North Polar Spur (NPS) is the brightest filament of Loop I, a large\ncircular feature in the radio continuum sky. In this paper, a model consisting\nof two synchrotron emitting shells is presented that reproduces large-scale\nstructures revealed by recent polarization surveys. The polarized emission of\nthe NPS is reproduced by one of these shells. The other shell, which passes\nclose to the Sun, gives rise to polarized emission towards the Galactic poles.\nIt is proposed that X-ray emission seen towards the NPS is produced by\ninteraction of the two shells. Two OB-associations coincide with the centers of\nthe shells. A formation scenario of the Loop I region is suggested.", "(Abridged) We use 3D SPH calculations with higher resolution, as well as with\nmore realistic viscosity and sound-speed prescriptions than previous work to\nexamine the eccentric instability which underlies the superhump phenomenon in\nsemi-detached binaries. We illustrate the importance of the two-armed spiral\nmode in the generation of superhumps. Differential motions in the fluid disc\ncause converging flows which lead to strong spiral shocks once each superhump\ncycle. The dissipation associated with these shocks powers the superhump. We\ncompare 2D and 3D results, and conclude that 3D simulations are necessary to\nfaithfully simulate the disc dynamics. We ran our simulations for unprecedented\ndurations, so that an eccentric equilibrium is established except at high mass\nratios where the growth rate of the instability is very low. Our improved\nsimulations give a closer match to the observed relationship between superhump\nperiod excess and binary mass ratio than previous numerical work. The observed\nblack hole X-ray transient superhumpers appear to have systematically lower\ndisc precession rates than the cataclysmic variables. This could be due to\nhigher disc temperatures and thicknesses. The modulation in total viscous\ndissipation on the superhump period is overwhelmingly from the region of the\ndisc within the 3:1 resonance radius. As the eccentric instability develops,\nthe viscous torques are enhanced, and the disc consequently adjusts to a new\nequilibrium state, as suggested in the thermal-tidal instability model. We\nquantify this enhancement in the viscosity, which is ~10 per cent for q=0.08.\nWe characterise the eccentricity distributions in our accretion discs, and show\nthat the entire body of the disc partakes in the eccentricity.", "Hypervelocity stars (HVSs) are a natural consequence of the presence of a\nmassive nuclear black hole (Sgr A*) in the Galactic Center. Here we use the\nBrown et al. sample of unbound and bound HVSs together with numerical\nsimulations of the propagation of HVSs in the Milky Way halo to constrain three\nplausible ejection mechanisms: 1) the scattering of stars bound to Sgr A* by an\ninspiraling intermediate-mass black hole (IMBH); 2) the disruption of stellar\nbinaries in the tidal field of Sgr A*; and 3) the two-body scattering of stars\noff a cluster of stellar-mass black holes orbiting Sgr A*. We compare the\npredicted radial and velocity distributions of HVSs with the limited-statistics\ndataset currently available, and show that the IMBH model appears to produce a\nspectrum of ejection velocities that is too flat. Future astrometric and deep\nwide-field surveys of HVSs should shed unambiguous light on the stellar\nejection mechanism and probe the Milky Way potential on scales as large as 200\nkpc.", "We analyze five epochs of Spitzer Space Telescope/Infrared Array Camera\n(IRAC) observations of the nearby spiral galaxy M33. Each epoch covered nearly\na square degree at 3.6, 4.5, and 8.0 microns. The point source catalog from the\nfull dataset contains 37,650 stars. The stars have luminosities characteristic\nof the asymptotic giant branch and can be separated into oxygen-rich and\ncarbon-rich populations by their [3.6] - [4.5] colors. The [3.6] - [8.0] colors\nindicate that over 80% of the stars detected at 8.0 microns have dust shells.\nPhotometric comparison of epochs using conservative criteria yields a catalog\nof 2,923 variable stars. These variables are most likely long-period variables\namidst an evolved stellar population. At least one-third of the identified\ncarbon stars are variable.", "A room temperature nuclear magnetic resonance force microscope (MRFM), fitted\nin a $^1$Tesla electromagnet, is used to measure the nuclear spin relaxation of\n$^1$H in a micron-size (70ng) crystal of ammonium sulfate. NMR sequences,\ncombining both pulsed and continuous wave r.f. fields, have allowed us to\nmeasure mechanically $T_2$ and $T_1$, the transverse and longitudinal spin\nrelaxation times. Because two spin species with different $T_1$ values are\nmeasured in our $7\\mu{\\rm m}$ thick crystal, magnetic resonance imaging of\ntheir spatial distribution inside the sample section are performed. To\nunderstand quantitatively the measured signal, we carefully study the influence\nof the spin-lattice relaxation and the non-adiabaticity of the c.w. sequence on\nthe intensity and time dependence of the detected signal.", "The magnetic order resulting from a confinement-adapted\nRuderman-Kittel-Kasuya-Yosida indirect exchange between magnetic moments in the\nmetallic phase of a AlAs/Ga(1-x)Mn(x)As quantum well is studied by Monte Carlo\nsimulation. This coupling mechanism involves magnetic moments and carriers\n(holes), both coming from the same Mn(2+) ions. It leads to a paramagnetic, a\nferromagnetic, or a canted spin phase, depending on the carrier concentration,\nand on the magnetic layer width. It is shown that high transition temperatures\nmay be obtained.", "We study the effects of quasiparticle interactions on disorder-induced\nlocalization of Dirac-like nodal excitations in superconducting high-$T_c$\ncuprates. As suggested by the experimental ARPES and terahertz conductivity\ndata in $Bi_2Sr_2CaCu_2O_{8+\\delta}$, we focus on the interactions mediated by\nthe order parameter fluctuations near an incipient second pairing transition\n$d\\to d+is$. We find interaction corrections to the density of states, specific\nheat, and conductivity as well as phase and energy relaxation rates and assess\nthe applicability of the recent localization scenarios for non-interacting\nrandom Dirac fermions to the cuprates.", "It is argued that close to a Coulomb interacting quantum critical point, the\ninteraction between two vortices in a disordered superconducting thin film\nseparated by a distance $r$ changes from logarithmic in the mean-field region\nto $1/r$ in the region dominated by quantum critical fluctuations. This gives\nsupport to the charge-vortex duality picture of the observed reflection\nsymmetry in the current-voltage characteristics on both sides of the\ntransition.", "We present a multiwavelength study of the poor cluster RX J1117.4+0743 ([VMF\n98] 097) at z=0.485, based on GMOS/Gemini South g', r' photometry and\nspectroscopy, and XMM-Newton observations. We examine its nature and\nsurroundings by analyzing the projected galaxy distribution, the galaxy\nvelocity distribution, the weak-lensing mass reconstruction, and the X-ray\nspectroscopy and imaging. The cluster shows a complex morphology. It is\ncomposed by at least two structures along the line-of-sight, with velocity\ndispersions of 592+-82 km s^-1 and 391+-85 km s^-1 respectively. Other\nstructures are also detected in X-ray, in the galaxy projected number density\nmap, and by weak-lensing. One of these clumps, could be gravitationally bound\nand associated to the main cluster. The derived temperature and bolometric\nX-ray luminosity reveal that [VMF 98] 097 behave like a normal cluster, in\nagreement with Lx-Tx correlation found for both local (z=0) and moderate\nredshift (z~0.4) clusters. We find that the mass determination inferred from\nweak-lensing is in average 3 to 4.8 times higher (depending on the model\nassumed) than the X-ray mass. We have two possible explanations for this\ndiscrepancy: i) the cluster is in non-equilibrium, then the deviation of the\nX-ray estimated mass from the true value can be as high as a factor of two; ii)\nthe intervening mass along the line-of-sight of the cluster is producing an\nover-estimation of the weak-lensing mass. Based on the analysis presented, we\nconclude that [VMF 98] 097 is a perturbed cluster with at least two\nsubstructures in velocity space and with other nearby structures at projected\ndistances of about 1 h^-1 Mpc. This cluster is an example of a poor cluster\ncaught in the process of accreting sub-structures to become a rich cluster.", "We show that the density profile of a Fermi gas in rapidly rotating potential\nwill develop prominent features reflecting the underlying Landau level like\nenergy spectrum. Depending on the aspect ratio of the trap, these features can\nbe a sequence of ellipsoidal volumes or a sequence of quantized steps.", "Cosmic infrared background (CIB) includes emissions from objects inaccessible\nto current telescopic studies, such as the putative Population III, the first\nstars. Recently, strong direct evidence for significant CIB levels produced by\nthe first stars came from CIB fluctuations discovered in deep Spitzer images.\nSuch CIB levels should have left a unique absorption feature in the spectra of\nhigh-z GRBs and blazars as suggested in [4]. This is observable with GLAST\nsources at z>2 and measuring this absorption will give important information on\nenergetics and constituents of the first stars era.", "The application of Superheated Droplet Detectors (SDDs) to dark matter\nsearches has so far been confined to the light nuclei refrigerants C2ClF5 and\nC4F10 (SIMPLE and PICASSO, respectively), with a principle sensitivity to\nspin-dependent interactions. Given the competitive results of these devices, as\na result of their intrinsic insensitivity to backgrounds, we have developed a\nprototype trifluoroiodomethane (CF3I)-loaded SDD with increased sensitivity to\nspin-independent interactions as well. A low (0.102 kgd) exposure test\noperation of two high concentration, 1 liter devices is described, and the\nresults compared with leading experiments in both spin-dependent and\n-independent sectors. Although competitive in both sectors when the difference\nin exposures is accounted for, a problem with fracturing of the detector gel\nmust be addressed before significantly larger exposures can be envisioned.", "We investigate the dynamics of a classical particle in a one-dimensional\ntwo-wave potential composed of two periodic potentials, that are\ntime-independent and of the same amplitude and periodicity. One of the periodic\npotentials is externally driven and performs a translational motion with\nrespect to the other. It is shown that if one of the potentials is of the\nratchet type, translation of the potential in a given direction leads to motion\nof the particle in the same direction, whereas translation in the opposite\ndirection leaves the particle localized at its original location. Moreover,\neven if the translation is random, but still has a finite velocity, an\nefficient directed transport of the particle occurs.", "Results are presented for the phase separation process of a binary mixture\nsubject to an uniform shear flow quenched from a disordered to a homogeneous\nordered phase. The kinetics of the process is described in the context of the\ntime-dependent Ginzburg-Landau equation with an external velocity term. The\nlarge-N approximation is used to study the evolution of the model in the\npresence of a stationary flow and in the case of an oscillating shear.\n  For stationary flow we show that the structure factor obeys a generalized\ndynamical scaling. The domains grow with different typical lengthscales $R_x$\nand $R_\\perp$ respectively in the flow direction and perpendicularly to it. In\nthe scaling regime $R_\\perp \\sim t^{\\alpha_\\perp}$ and $R_x \\sim \\gamma\nt^{\\alpha_x}$ (with logarithmic corrections), $\\gamma $ being the shear rate,\nwith $\\alpha_x=5/4$ and $\\alpha_\\perp =1/4$. The excess viscosity $\\Delta \\eta$\nafter reaching a maximum relaxes to zero as $\\gamma ^{-2}t^{-3/2}$. $\\Delta\n\\eta$ and other observables exhibit log-time periodic oscillations which can be\ninterpreted as due to a growth mechanism where stretching and break-up of\ndomains cyclically occur.\n  In the case of an oscillating shear a cross-over phenomenon is observed:\nInitially the evolution is characterized by the same growth exponents as for a\nstationary flow. For longer times the phase separating structure cannot align\nwith the oscillating drift and a different regime is entered with an isotropic\ngrowth and the same exponents of the case without shear.", "The discovery of a flux excess in the far-ultraviolet (UV) spectrum of\nelliptical galaxies was a major surprise in 1969. While it is now clear that\nthis UV excess is caused by an old population of hot helium-burning stars\nwithout large hydrogen-rich envelopes, rather than young stars, their origin\nhas remained a mystery. Here we show that these stars most likely lost their\nenvelopes because of binary interactions, similar to the hot subdwarf\npopulation in our own Galaxy. We have developed an evolutionary population\nsynthesis model for the far-UV excess of elliptical galaxies based on the\nbinary model developed by Han et al (2002, 2003) for the formation of hot\nsubdwarfs in our Galaxy. Despite its simplicity, it successfully reproduces\nmost of the properties of elliptical galaxies with a UV excess: the range of\nobserved UV excesses, both in $(1550-V)$ and $(2000-V)$, and their evolution\nwith redshift. We also present colour-colour diagrams for use as diagnostic\ntools in the study of elliptical galaxies. The model has major implications for\nunderstanding the evolution of the UV excess and of elliptical galaxies in\ngeneral. In particular, it implies that the UV excess is not a sign of age, as\nhad been postulated previously, and predicts that it should not be strongly\ndependent on the metallicity of the population, but exists universally from\ndwarf ellipticals to giant ellipticals.", "We continue our program of single-site observations of pulsating subdwarf B\n(sdB) stars and present the results of extensive time series photometry of HS\n0039+4302 and HS 0444+0458. Both were observed at MDM Observatory during the\nfall of 2005. We extend the number of known frequencies for HS 0039+4302 from 4\nto 14 and discover one additional frequency for HS 0444+0458, bringing the\ntotal to three. We perform standard tests to search for multiplet structure,\nmeasure amplitude variations, and examine the frequency density to constrain\nthe mode degree $\\ell$.\n  Including the two stars in this paper, 23 pulsating sdB stars have received\nfollow-up observations designed to decipher their pulsation spectra. It is\nworth an examination of what has been detected. We compare and contrast the\nfrequency content in terms of richness and range and the amplitudes with\nregards to variability and diversity. We use this information to examine\nobservational correlations with the proposed $\\kappa$ pulsation mechanism as\nwell as alternative theories.", "We present a new generalized topological current in terms of the order\nparameter field $\\vec \\phi$ to describe the topological defect system in O(n)\nsymmetric time-dependent Ginzburg-Landau model. With the aid of the $%\n\\phi$-mapping method, the structure of the topological defects and the\ntopological quantization of their topological charges in TDGL model are\nobtained under the condition that the Jacobian $% J(\\frac \\phi v)\\neq 0$. We\nshow that the topological defects are generated from the zero points of the\norder parameter field $\\vec \\phi$, and the topological charges of these\ntopological defects are topological quantized in terms of the Hopf indices and\nBrouwer degrees of $\\phi$-mapping under the condition. When $J(\\frac \\phi\nv)=0$, it is shown that there exist the crucial case of branch process. Based\non the implicit function theorem and the Taylor expansion, we detail the\nbifurcation of generalized topological current and find different directions of\nthe bifurcation. The topological defects in TDGL model are found splitting or\nmerging at the degenerate point of field function $\\vec \\phi $ but the total\ncharge of the topological defects is still unchanged.", "Diffuse emission is produced in energetic cosmic ray (CR) interactions,\nmainly protons and electrons, with the interstellar gas and radiation field and\ncontains the information about particle spectra in distant regions of the\nGalaxy. It may also contain information about exotic processes such as dark\nmatter annihilation, black hole evaporation etc. A model of the diffuse\nemission is important for determination of the source positions and spectra.\nCalculation of the Galactic diffuse continuum gamma-ray emission requires a\nmodel for CR propagation as the first step. Such a model is based on theory of\nparticle transport in the interstellar medium as well as on many kinds of data\nprovided by different experiments in Astrophysics and Particle and Nuclear\nPhysics. Such data include: secondary particle and isotopic production cross\nsections, total interaction nuclear cross sections and lifetimes of radioactive\nspecies, gas mass calibrations and gas distribution in the Galaxy (H_2, H I, H\nII), interstellar radiation field, CR source distribution and particle spectra\nat the sources, magnetic field, energy losses, gamma-ray and synchrotron\nproduction mechanisms, and many other issues. We are continuously improving the\nGALPROP model and the code to keep up with a flow of new data. Improvement in\nany field may affect the Galactic diffuse continuum gamma-ray emission model\nused as a background model by the GLAST LAT instrument. Here we report about\nthe latest improvements of the GALPROP and the diffuse emission model.", "We discuss Subaru and Spitzer Space Telescope imaging and spectroscopy of M87\nin the mid-infrared from 5-35 um. These observations allow us to investigate\nmid-IR emission mechanisms in the core of M87 and to establish that the\nflaring, variable jet component HST-1 is not a major contributor to the mid-IR\nflux. The Spitzer data include a high signal-to-noise 15-35 $\\mu$m spectrum of\nthe knot A/B complex in the jet, which is consistent with synchrotron emission.\nHowever, a synchrotron model cannot account for the observed {\\it nuclear}\nspectrum, even when contributions from the jet, necessary due to the degrading\nof resolution with wavelength, are included. The Spitzer data show a clear\nexcess in the spectrum of the nucleus at wavelengths longer than 25 um, which\nwe model as thermal emission from cool dust at a characteristic temperature of\n55 \\pm 10 K, with an IR luminosity \\sim 10^{39} {\\rm ~erg ~s^{-1}}. Given\nSpitzer's few-arcsecond angular resolution, the dust seen in the nuclear\nspectrum could be located anywhere within ~5'' (390 pc) of the nucleus. In any\ncase, the ratio of AGN thermal to bolometric luminosity indicates that M87 does\nnot contain the IR-bright torus that classical unified AGN schemes invoke.\nHowever, this result is consistent with theoretical predictions for\nlow-luminosity AGNs", "We identify all possible classes of solutions for two-component Bose-Einstein\ncondensates (BECs) within the Thomas-Fermi (TF) approximation, and check these\nresults against numerical simulations of the coupled Gross-Pitaevskii equations\n(GPEs). We find that they can be divided into two general categories. The first\nclass contains solutions with a region of overlap between the components. The\nother class consists of non-overlapping wavefunctions, and contains also\nsolutions that do not possess the symmetry of the trap. The chemical potential\nand average energy can be found for both classes within the TF approximation by\nsolving a set of coupled algebraic equations representing the normalization\nconditions for each component. A ground state minimizing the energy (within\nboth classes of the states) is found for a given set of parameters\ncharacterizing the scattering length and confining potential. In the TF\napproximation, the ground state always shares the symmetry of the trap.\nHowever, a full numerical solution of the coupled GPEs, incorporating the\nkinetic energy of the BEC atoms, can sometimes select a broken-symmetry state\nas the ground state of the system. We also investigate effects of finite-range\ninteractions on the structure of the ground state.", "We study a model for the dynamics of vortices in type II superconductors. In\nparticular, we discuss glassy ``off equilibrium'' properties and ``aging'' in\nmagnetic creep. At low temperatures a crossover point is found, Tg, where\nrelaxation times seem to diverge a' la Vogel-Tamman-Fulcher. Magnetic creep\nchanges by crossing Tg: above Tg power law creep is found asymptotically\nfollowed by stretched exponential saturation; below Tg the creep is logarithmic\nand vortex motion strongly subdiffusive. In this region violation of time\ntranslation invariance is found along with important dynamical scaling\nproperties. A thermodynamic glassy transition point can be found at a lower\ntemperature Tc.", "We report the detection of the millisecond pulsar B1257+12 with the Chandra\nX-ray Observatory. In a 20 ks exposure we detected 25 photons from the pulsar,\nwith energies between 0.4 and 2.0 keV, corresponding to the flux F_X=(4.4+/-\n0.9)*10^{-15} ergs s^{-1} cm^{-2} in this energy range. The X-ray spectrum can\nbe described by a power-law model with photon index Gamma = 2.8 and luminosity\nL_X \\approx 2.5*10^{29} ergs s^{-1} in the 0.3--8 keV band, for a plausible\ndistance of 500 pc and hydrogen column density N_H=3*10^{20} cm^{-2}.\nAlternatively, the spectrum can be fitted by a blackbody model with kT ~ 0.22\nkeV and projected emitting area ~2000 m^2. If the thermal X-rays are emitted\nfrom two symmetric polar caps, the bolometric luminosity of the two caps is 2\nL_bol ~ 3*10^{29} ergs s^{-1}. We compared our results with the data on other\n30 millisecond pulsars observed in X-rays and found that the apparent X-ray\nefficiency of PSR B1257+12, L_X/Edot ~ 3*10^{-5} for d=500 pc, is lower than\nthose of most of millisecond pulsars. This might be explained by an unfavorable\norientation of the X-ray pulsar beam if the radiation is magnetospheric, or by\nstrong asymmetry of polar caps if the radiation is thermal (e.g., one of the\npolar caps is much brighter than the other and remains invisible for most part\nof the pulsar period). Alternatively, it could be attributed to absorption of\nX-rays in circumpulsar matter, such as a flaring debris disk left over after\nformation of the planetary system around the pulsar.", "The self consistent version of the density functional theory (DFT) is\npresented, which allows to calculate the ground state and dynamic properties of\nfinite multi-electron systems such as atoms, molecules and clusters. The exact\nfunctional equation for the effective interaction, using which one can\nconstruct the action functional, density functional, the response functions,\nand excitation spectra of the considered systems, are discussed. We have also\nrelated the eigenvalues of the single-particle Kohn-Sham equations to the real\nsingle-particle spectra. We begin with the standard action functional and show\nthat it is useful in calculating the linear response functions via which all\nphysical characteristics of a many-body system can be expressed. It is shown,\nthat function can be causal (retarded), noncausal and advanced ones. This\nresolves the well known paradox related to the causality and symmetry\nproperties of the response functions and the effective interaction.", "The observed association of Long Gamma-Ray Bursts (LGRBs) with peculiar Type\nIc supernovae gives support to Woosley`s collapsar/hypernova model, in which\nthe GRB is produced by the collapse of the rapidly rotating core of a massive\nstar to a black hole. The association of LGRBs with small star-forming galaxies\nsuggests low-metallicity to be a condition for a massive star to evolve to the\ncollapsar stage. Both completely-mixed single star models and binary star\nmodels are possible. In binary models the progenitor of the GRB is a massive\nhelium star with a close companion. We find that tidal synchronization during\ncore-helium burning is reached on a short timescale (less than a few\nmillennia). However, the strong core-envelope coupling in the subsequent\nevolutionary stages is likely to rule out helium stars with main-sequence\ncompanions as progenitors of hypernovae/GRBs. On the other hand, helium stars\nin close binaries with a neutron-star or black-hole companion can, despite the\nstrong core-envelope coupling in the post-helium burning phase, retain\nsufficient core angular momentum to produce a hypernova/GRB.", "A simple model for addition spectra in quantum dots is proposed and studied.\nIt is an extension of the standard charging model which assumes that the charge\nspreads uniformely over the entire dot. The proposed model attempts to account\nfor a nonuniform distribution of the charge, by introducing an extra parameter\nU. When U increases, the distribution of the conductance peak spacings changes\nfrom the Wigner-Dyson shape towards a broader, more symmetric distribution.", "We present here an updated description of the \"Scenario Machine\" code. This\ntool is used to carry out a population synthesis of binary stars. Previous\nversion of the description can be found at\nhttp://xray.sai.msu.ru/~mystery//articles/review/contents.html", "We present the preliminary results from two new surveys of blazars that have\ndirect implications on the GLAST detection of extragalactic sources from two\ndifferent perspectives: microwave selection and a combined deep X-ray/radio\nselection. The first one is a 41 GHz flux-limited sample extracted from the\nWMAP 3-yr catalog of microwave point sources. This is a statistically well\ndefined sample of about 200 blazars and radio galaxies, most of which are\nexpected to be detected by GLAST. The second one is a new deep survey of\nBlazars selected among the radio sources that are spatially coincident with\nserendipitous sources detected in deep X-ray images (0.3-10 keV) centered on\nthe Gamma Ray Bursts (GRB) discovered by the Swift satellite. This sample is\nparticularly interesting from a statistical viewpoint since a) it is unbiased\nas GRBs explode at random positions in the sky, b) it is very deep in the X-ray\nband (\\fx \\simgt $10^{-15}$ \\ergs) with a position accuracy of a few\narc-seconds, c) it will cover a fairly large (20-30 square deg.) area of sky,\nd) it includes all blazars with radio flux (1.4 GHz) larger than 10 mJy, making\nit approximately two orders of magnitude deeper than the WMAP sample and about\none order of magnitude deeper than the deepest existing complete samples of\nradio selected blazars, and e) it can be used to estimate the amount of\nunresolved GLAST high latitude gamma-ray background and its anisotropy\nspectrum.", "The MOJAVE sample is the first large radio-selected, VLBI-monitored AGN\nsample for which complete X-ray spectral information is being gathered. We\nreport on the status of Swift survey observations which complement the\navailable archival X-ray data at 0.3-10 keV and in the UV with its XRT and UVOT\ninstruments. Many of these 133 radio-brightest AGN in the northern sky are now\nbeing observed for the first time at these energies. These and complementary\nother multi-wavelength observations provide a large statistical sample of\nradio-selected AGN whose spectral energy distributions are measured from radio\nto gamma-ray wavelengths, available at the beginning of GLAST operations in\n2008. Here, we report the X-ray spectral characteristics of 36 of these\npreviously unobserved MOJAVE sources. In addition, the number of MOJAVE sources\ndetected by the BAT instrument in the hard X-ray band is growing: we report the\ndetection of five new blazars with BAT.", "We present Spitzer IRS low resolution, mid-IR spectra of a sample of 25 high\nluminosity QSOs at 2<z<3.5. When combined with archival IRS observations of\nlocal, low luminosity type-I AGNs, the sample spans five orders of magnitude in\nluminosity. We find that the continuum dust thermal emission at\nlambda(rest)=6.7um is correlated with the optical luminosity, following the\nnon-linear relation L(6.7um) propto L(5100A)^0.82. We also find an anti\ncorrelation between the ratio L(6.7um)/L(5100A) and the [OIII]5007A line\nluminosity. These effects are interpreted as a decreasing covering factor of\nthe circumnuclear dust as a function of luminosity. Such a result is in\nagreement with the decreasing fraction of absorbed AGNs as a function of\nluminosity recently found in various surveys. We clearly detect the silicate\nemission feature in the average spectrum, but also in four individual objects.\nThese are the Silicate emission in the most luminous objects obtained so far.\nWhen combined with the silicate emission observed in local, low luminosity\ntype-I AGNs, we find that the silicate emission strength is correlated with\nluminosity.\n  The silicate strength of all type-I AGNs also follows a positive correlation\nwith the black hole mass and with the accretion rate. The Polycyclic Aromatic\nHydrocarbon (PAH) emission features, expected from starburst activity, are not\ndetected in the average spectrum of luminous, high-z QSOs. The upper limit\ninferred from the average spectrum points to a ratio between PAH luminosity and\nQSO optical luminosity significantly lower than observed in lower luminosity\nAGNs, implying that the correlation between star formation rate and AGN power\nsaturates at high luminosities.", "We apply lattice Boltzmann method to study the phase separation of a\ntwo-dimensional binary fluid mixture in shear flow. The algorithm can simulate\nsystems described by the Navier-Stokes and convection-diffusion equations. We\npropose a new scheme for imposing the shear flow which has the advantage of\npreserving mass and momentum conservation on the boundary walls without\nintroducing slip velocities. Our main results concern the presence of two\ntypical lenght scales in the phase separation process, corresponding to domains\nwith two different thicknesses. Our simulations at low viscosity confirm\nprevious results only valid in the limit of infinite viscosity.", "In the present work ferromagnetic ordering in the Hubbard model generalized\nby taking into account the inter-atomic exchange interaction and correlated\nhopping in partially filled narrow band is considered. Expressions for the\nmagnetization and Curie temperature as functions of model parameters and band\nfilling are obtained in the case of weak intra-atomic Coulomb interaction.\nCondition of ferromagnetic state realization is found. The obtained results\nindicate the important role of correlated hopping.", "Extrasolar planetary systems range from hot Jupiters out to icy comet belts\nmore distant than Pluto. We explain this diversity in a model where the mass of\nsolids in the primordial circumstellar disk dictates the outcome. The star\nretains measures of the initial heavy-element (metal) abundance that can be\nused to map solid masses onto outcomes, and the frequencies of all classes are\ncorrectly predicted. The differing dependences on metallicity for forming\nmassive planets and low-mass cometary bodies are also explained. By\nextrapolation, around two-thirds of stars have enough solids to form Earth-like\nplanets, and a high rate is supported by the first detections of low-mass\nexo-planets.", "We present mid-IR spectral decomposition of a sample of 48 Spitzer-selected\nULIRGs spanning z~1-3 and likely L_IR~10^12-10^13Lsun. Our study aims at\nquantifying the star-formation and AGN processes in these sources which recent\nresults suggest have evolved strongly between the observed epoch and today. To\ndo this, we study the mid-IR contribution of PAH emission, continuum, and\nextinction. About 3/4 of our sample are continuum- (i.e. AGN) dominated\nsources, but ~60% of these show PAH emission, suggesting the presence of\nstar-formation activity. These sources have redder mid-IR colors than typical\noptically-selected quasars. About 25% of our sample have strong PAH emission,\nbut none are likely to be pure starbursts as reflected in their relatively high\n5um hot dust continua. However, their steep 30um-to-14um slopes suggest that\nstar-formation might dominate the total infrared luminosity. Six of our z~2\nsources have EW6.2>~0.3um and L_14um>~10^12Lsun (implying L_IR>~10^13Lsun). At\nthese luminosities, such high EW6.2 ULIRGs do not exist in the local Universe.\nWe find a median optical depth at 9.7um of <tau_9.7>=1.4. This is consistent\nwith local IRAS-selected ULIRGs, but differs from early results on\nSCUBA-selected z~2 ULIRGs. Similar to local ULIRGs about 25% of our sample show\nextreme obscuration (tau_9.7>~3) suggesting buried nuclei. In general, we find\nthat our sources are similar to local ULIRGs, but are an order of magnitude\nmore luminous. It is not clear whether our z~2 ULIRGs are simply scaled-up\nversions of local ULIRGs, or subject to fundamentally different physical\nprocesses.", "Spectral inversion techniques based on the cloud model are extremely useful\nfor the study of properties and dynamics of various chromospheric cloud-like\nstructures. Several inversion techniques are reviewed based on simple (constant\nsource function) and more elaborated cloud models, as well as on grids of\nsynthetic line profiles produced for a wide range of physical parameters by\ndifferent NLTE codes. Several examples are shown of how such techniques can be\nused in different chromospheric lines, for the study of structures of the quiet\nchromosphere, such as mottles/spicules, as well as for active region structures\nsuch as fibrils, arch filament systems (AFS), filaments and flares.", "The Bose-Einstein condensates recently created in trapped atomic gases are\nmesoscopic systems, in two senses: (a) Their size fall between macroscopic and\nmicroscopic systems; (b) They have a quantum phase that can be manipulated in\nexperiments. We review the theoretical and experimental facts about trapped\natomic gases, and give examples that emphasize their mesoscopic characters. One\nis the dynamics of collapse of a condensate with attractive interactions. The\nother is the creation of a 1D kink soliton that can be used as a mode-locked\natom laser.", "We discuss the momentum-space topology of 3+1 and 2+1 strongly correlated\nfermionic systems. For the 3+1 systems the important universality class is\ndetermined by the topologically stable Fermi points in momentum space. In the\nextreme limit of low energy the condensed matter system of this universality\nclass acquires all the symmetries, which we know today in high energy physics:\nLorentz invariance, gauge invariance, general covariance, etc. The chiral\nfermions as well as gauge bosons and gravity field arise as fermionic and\nbosonic collective modes of the system. This introduces the conceptual\nsimilarity between such condensed matter and the quantum vacuum of Standard\nModel, which also contains the Fermi point. For the 2+1 fermionic systems the\nmomentum space topology gives rise to the quantization of different physical\nparameters, such as Hall conducivity and spin-Hall conductivity, and to quantum\nphase transitions with the abrupt change of the momentum-space topology. The\ncombined p-space and r-space topology determines in particular the topology of\nthe energy spectrum of fermion zero modes living within the topological\ndefects; fermionic charges of the topologically nontrivial extended objects;\naxial anomaly; etc.", "The Casimir effect for conductors at arbitrary temperatures is theoretically\nstudied. By using the analytical properties of the Green functions and applying\nthe Abel-Plan formula to Lifshitz's equation, the Casimir force is presented as\nsum of a temperature dependent and vacuum contributions of the fluctuating\nelectromagnetic field. The general results are applied to the system consisting\nof a bulk conductor and a thin metal film. It is shown that a characteristic\nfrequency of the thermal fluctuations in this system is proportional to the\nsquare root of a thickness of the metal film. For the case of the sufficiently\nhigh temperatures when the thermal fluctuations play the main role in the\nCasimir interaction, this leads to the growth of the effective dielectric\npermittivity of the film and to a disappearance of the dependence of Casimir's\nforce on the sample thickness.", "The role of surface collective excitations in the electron relaxation in\nsmall metal particles is studied. It is shown that the dynamically screened\nelectron-electron interaction in a nanoparticle contains a size-dependent\ncorrection induced by the surface. This leads to new channels of quasiparticle\nscattering accompanied by the emission of surface collective excitations. In\nnoble-metal particles, the dipole collective excitations (surface plasmons)\nmediate a resonant scattering of d-holes to the conduction band. The role of\nthis effect in the ultrafast optical dynamics of small nanoparticles is\nstudied. With decreasing nanoparticle size, it leads to a strong change in the\ndifferential absorption lineshape and a strong frequency dependence of the\nrelaxation near the surface plasmon resonance. The experimental implications of\nthese results in ultrafast pump-probe spectroscopy are addressed. The\nsize-dependence of conduction electron scattering rates is also discussed.", "The CORSIKA program, usually used to simulate extensive cosmic ray air\nshowers, has been adapted to work in a water or ice medium. The adapted CORSIKA\ncode was used to simulate hadronic showers produced by neutrino interactions.\nThe simulated showers have been used to study the spatial distribution of the\ndeposited energy in the showers. This allows a more precise determination of\nthe acoustic signals produced by ultra high energy neutrinos than has been\npossible previously. The properties of the acoustic signals generated by such\nshowers are described.", "Instabilities for boson-fermion mixed condensates of trapped Alkali atoms due\nto the boson-fermion attractive interaction are studied using a variational\nmethod. Three regions are shown for their instabilities according to the\nboson-fermion interaction strength: stable, meta-stable and unstable ones. The\nstability condition is obtained analytically from the asymptotic expansion of\nthe variational total energy. The life-time of metastable states is discussed\nfor tunneling decay, and is estimated to be very long. It suggests that, except\nnear the unstable border, meta-stable mixed condensate should be almost-stable\nagainst clusterizations. The critical border between meta-stable and unstable\nphases is calculated numerically and is shown to be consistent with the\nM{\\o}lmer scaling condition.", "Massive X-ray binaries are formed by a compact object that accretes matter\nfrom the stellar wind of an early-type donor star. In some of these systems,\ncalled microquasars, relativistic jets are launched from the surroundings of\nthe compact object. Such jets interact with the photon field of the companion\nstar, the stellar wind, and, at large distances, with the interstellar medium.\nIn this paper I will review the main results of such interactions with\nparticular emphasis on the production of high-energy photons and neutrinos. The\ncase of some specific systems, like LS I +61 303, will be discussed in some\ndetail. Prospects for future observations at different wavelengths of this type\nof objects will be presented.", "In these lectures, superconductivity in impure thin films close to the\nabsolute zero of temperature is discussed. The behavior as function of the\napplied magnetic field and the amount of impurities suggests the presence of a\nsuperconductor-insulator transition at zero temperature. The theory of\nsuperconductivity in the limit where all the electrons become tightly bound in\npairs is used to explain the main characteristics of the transition. In that\nlimit, where the theory becomes equivalent to a phase-only theory, electron\npairs exist on either side of the transition. The presentation is pedagogical\nin nature and includes exercises as a learning aid for those new to the field.", "The properties of galaxies are strongly correlated with their environment,\nwith red galaxies dominating galaxy clusters and blue galaxies dominating the\ngeneral field. However, not all field galaxies are young: studies of the\ncolors, line strengths, and M/L ratios of massive early-type galaxies at\n0<z<1.3 show that the most massive galaxies do not seem to care about their\nsurroundings, and have very similar ages irrespective of their environment.\nThere is good evidence that the growth of these galaxies does continue longer\nin the field than in clusters, via (nearly) dissipationless mergers of already\nold galaxies. These results are consistent with predictions of recent galaxy\nformation models, which incorporate AGN feedback to suppress star formation in\nthe most massive halos. Systematic studies of the relation of galaxies with\ntheir environment beyond z=1 are difficult, and still somewhat contradictory.\nIntriguingly both the DEEP2 and VVDS surveys find that the color-density\nrelation disappears at z~1.3, unfortunately just at the point where both\nsurveys become highly incomplete. On the other hand, clustering studies at\nz~2.5 have shown that red galaxies cluster more strongly than blue galaxies,\nimplying that the color-density relation was already in place at that redshift.", "We present a new technique to compute simultaneously valid confidence\nintervals for a set of model parameters. We apply our method to the Wilkinson\nMicrowave Anisotropy Probe's (WMAP) Cosmic Microwave Background (CMB) data,\nexploring a seven dimensional space (tau, Omega_DE, Omega_M, omega_DM, omega_B,\nf_nu, n_s). We find two distinct regions-of-interest: the standard Concordance\nModel, and a region with large values of omega_DM, omega_B and H_0. This second\npeak in parameter space can be rejected by applying a constraint (or a prior)\non the allowable values of the Hubble constant. Our new technique uses a\nnon-parametric fit to the data, along with a frequentist approach and a smart\nsearch algorithm to map out a statistical confidence surface. The result is a\nconfidence ``ball'': a set of parameter values that contains the true value\nwith probability at least 1-alpha. Our algorithm performs a role similar to the\noften used Markov Chain Monte Carlo (MCMC), which samples from the posterior\nprobability function in order to provide Bayesian credible intervals on the\nparameters. While the MCMC approach samples densely around a peak in the\nposterior, our new technique allows cosmologists to perform efficient analyses\naround any regions of interest: e.g., the peak itself, or, possibly more\nimportantly, the 1-alpha confidence surface.", "Red clump giants in the Galactic bulge are approximate standard candles and\nhence they can be used as distance indicators. We compute the proper motion\ndispersions of RCG stars in the Galactic bulge using the proper motion\ncatalogue from the second phase of the Optical Gravitational Microlensing\nExperiment (OGLE-II, Sumi et al. 2004) for 45 fields. The proper motion\ndispersions are measured to a few per cent accuracy due to the large number of\nstars in the fields. The observational sample is comprised of 577736 stars.\nThese observed data are compared to a state-of-the-art particle simulation of\nthe Galactic bulge region. The predictions are in rough agreement with\nobservations, but appear to be too anisotropic in the velocity ellipsoid. We\nnote that there is significant field-to-field variation in the observed proper\nmotion dispersions. This could either be a real feature, or due to some unknown\nsystematic effect.", "We examine the nature of large-scale, coronal, propagating wave fronts (``EIT\nwaves'') and find they are incongruous with solutions using fast-mode MHD\nplane-wave theory. Specifically, we consider the following properties:\nnon-dispersive single pulse manifestions, observed velocities below the local\nAlfven speed, and different pulses which travel at any number of constant\nvelocities, rather than at the ``predicted'' fast-mode speed. We discuss the\npossibility of a soliton-like explanation for these phenomena, and show how it\nis consistent with the above-mentioned aspects.", "We investigate hole transport in polymer light-emitting-diodes in which the\nemissive layer is made of liquid-crystalline polymer chains aligned\nperpendicular to the direction of transport. Calculations of the current as a\nfunction of time via a random-walk model show excellent qualitative agreement\nwith experiments conducted on electroluminescent polyfluorene demonstrating\nnon-dispersive hole transport. The current exhibits a constant plateau as the\ncharge carriers move with a time-independent drift velocity, followed by a long\ntail when they reach the collecting electrode. Variation of the parameters\nwithin the model allows the investigation of the transition from non-dispersive\nto dispersive transport in highly aligned polymers. It turns out that large\ninter-chain hopping is required for non-dispersive hole transport and that\nstructural disorder obstructs the propagation of holes through the polymer\nfilm.", "We present mid-infrared (10.4 \\micron, 11.7 \\micron, and 18.3 \\micron)\nimaging intended to locate and characterize the suspected protostellar\ncomponents within the Bok globule CB54. We detect and confirm the protostellar\nstatus for the near-infrared source CB54YC1-II. The mid-infrared luminosity for\nCB54YC1-II was found to be $L_{midir} \\approx 8 L_\\sun$, and we estimate a\ncentral source mass of $M_* \\approx 0.8 M_\\sun$ (for a mass accretion rate of\n${\\dot M}=10^{-6} M_\\sun yr^{-1}$). CB54 harbors another near-infrared source\n(CB54YC1-I), which was not detected by our observations. The non-detection is\nconsistent with CB54YC1-I being a highly extinguished embedded young A or B\nstar or a background G or F giant. An alternative explanation for CB54YC1-I is\nthat the source is an embedded protostar viewed at an extremely high\ninclination angle, and the near-infrared detections are not of the central\nprotostar, but of light scattered by the accretion disk into our line of sight.\nIn addition, we have discovered three new mid-infrared sources, which are\nspatially coincident with the previously known dense core in CB54. The source\ntemperatures ($\\sim100$K) and association of the mid-infrared sources with the\ndense core suggests that these mid-infrared objects may be embedded class 0\nprotostars.", "Using a microscopic phase-space model of the membrane system, the boundary\ncondition at a membrane is derived. According to the condition, the substance\nflow across the membrane is proportional to the difference of the substance\nconcentrations at the opposite membrane surfaces. The Green's function of the\ndiffusion equation is found for the derived boundary condition and the exact\nsolution of the equation is given.", "We introduce a convenient parametrization of dark energy models that is\ngeneral enough to include several modified gravity models and generalized forms\nof dark energy. In particular we take into account the linear perturbation\ngrowth factor, the anisotropic stress and the modified Poisson equation. We\ndiscuss the sensitivity of large scale weak lensing surveys like the proposed\nDUNE satellite to these parameters. We find that a large-scale weak-lensing\ntomographic survey is able to easily distinguish the Dvali-Gabadadze-Porrati\nmodel from LCDM and to determine the perturbation growth index to an absolute\nerror of 0.02-0.03.", "The state of a thermodynamic system being characterized by its set of\nextensive variables $q^{i}(i=1,...,n) ,$ we write the associated intensive\nvariables $\\gamma_{i},$ the partial derivatives of the entropy $\nS(q^{1},...,q^{n}) \\equiv q_{0},$ in the form $\\gamma_{i}=-p_{i}/p_{0}$ where\n$p_{0}$ behaves as a gauge factor. When regarded as independent, the variables\n$q^{i},p_{i}(i=0,...,n) $ define a space $\\mathbb{T}$ having a canonical\nsymplectic structure where they appear as conjugate. A thermodynamic system is\nrepresented by a $n+1$-dimensional gauge-invariant Lagrangian submanifold\n$\\mathbb{M}$ of $\\mathbb{T}.$ Any thermodynamic process, even dissipative,\ntaking place on $\\mathbb{M}$ is represented by a Hamiltonian trajectory in\n$\\mathbb{T},$ governed by a Hamiltonian function which is zero on $\\mathbb{M}.$\nA mapping between the equations of state of different systems is likewise\nrepresented by a canonical transformation in $\\mathbb{T}.$ Moreover a natural\nRiemannian metric exists for any physical system, with the $q^{i}$'s as\ncontravariant variables, the $p_{i}$'s as covariant ones. Illustrative examples\nare given.", "We present a new model of BEC dynamics based on strong confinement near the\nground state. The model predicts oscillations in a two-component condensate,\nbased on interference of non-spreading wave packets moving within a pair of\ntilted nearly square potentials. The oscillations are similar to those recently\nreported for a magnetically trapped $^{87}$Rb condensate, and the model's\npredictions give good quantitative agreement with the experiments.", "Recent three-dimensional radiative hydrodynamics simulations of\nprotoplanetary disks report disparate disk behaviors, and these differences\ninvolve the importance of convection to disk cooling, the dependence of disk\ncooling on metallicity, and the stability of disks against fragmentation and\nclump formation. To guarantee trustworthy results, a radiative physics\nalgorithm must demonstrate the capability to handle both the high and low\noptical depth regimes. We develop a test suite that can be used to demonstrate\nan algorithm's ability to relax to known analytic flux and temperature\ndistributions, to follow a contracting slab, and to inhibit or permit\nconvection appropriately. We then show that the radiative algorithm employed by\nMeji\\'a (2004) and Boley et al. (2006) and the algorithm employed by Cai et al.\n(2006) and Cai et al. (2007, in prep.) pass these tests with reasonable\naccuracy. In addition, we discuss a new algorithm that couples flux-limited\ndiffusion with vertical rays, we apply the test suite, and we discuss the\nresults of evolving the Boley et al. (2006) disk with this new routine.\nAlthough the outcome is significantly different in detail with the new\nalgorithm, we obtain the same qualitative answers. Our disk does not cool fast\ndue to convection, and it is stable to fragmentation. We find an effective\n$\\alpha\\approx 10^{-2}$. In addition, transport is dominated by low-order\nmodes.", "We present broadband NIR spectra of A0620-00 obtained with SpeX on the IRTF.\nThe spectrum is characterized by a blue continuum on which are superimposed\nbroad emission lines of HI and HeII and a host of narrower absorption lines of\nneutral metals and molecules. Spectral type standard star spectra scaled to the\ndereddened spectrum of A0620-00 in K exceed the A0620-00 spectrum in J and H\nfor all stars of spectral type K7V or earlier, demonstrating that the donor\nstar, unless later than K7V, cannot be the sole NIR flux source in A0620-00. In\naddition, the atomic absorption lines in the K3V spectrum are too weak with\nrespect to those of A0620-00 even at 100% donor star contribution, restricting\nthe spectral type of the donor star in A0620-00 to later than K3V. Comparison\nof the A0620-00 spectrum to scaled K star spectra indicates that the CO\nabsorption features are significantly weaker in A0620-00 than in field dwarf\nstars. Fits of scaled model spectra of a Roche lobe-filling donor star to the\nspectrum of A0620-00 show that the best match to the CO absorption lines is\nobtained when the C abundance is reduced to [C/H] = -1.5. The donor star\ncontribution in the H waveband is determined to be 82+-2%. Combined with\nprevious published results from Froning & Robinson (2001) and Marsh et al.\n(1994), this gives a precise mass for the black hole in A0620-00 of M_BH =\n9.7+-0.6 M_solar.", "In the framework of melting as a dislocation-mediated phase transition we\nderive an equation for the pressure dependence of the melting temperatures of\nthe elements valid up to pressures of order their ambient bulk moduli. Melting\ncurves are calculated for Al, Mg, Ni, Pb, the iron group (Fe, Ru, Os), the\nchromium group (Cr, Mo, W), the copper group (Cu, Ag, Au), noble gases (Ne, Ar,\nKr, Xe, Rn), and six actinides (Am, Cm, Np, Pa, Th, U). These calculated\nmelting curves are in good agreement with existing data. We also discuss the\napparent equivalence of our melting relation and the Lindemann criterion, and\nthe lack of the rigorous proof of their equivalence. We show that the would-be\nmathematical equivalence of both formulas must manifest itself in a new\nrelation between the Gr\\\"{u}neisen constant, bulk and shear moduli, and the\npressure derivative of the shear modulus.", "We re-discuss the evolutionary state of upper main sequence magnetic stars\nusing a sample of Ap and Bp stars with accurate Hipparcos parallaxes and\ndefinitely determined longitudinal magnetic fields. We confirm our previous\nresults obtained from the study of Ap and Bp stars with accurate measurements\nof the mean magnetic field modulus and mean quadratic magnetic fields that\nmagnetic stars of mass M < 3 M_sun are concentrated towards the centre of the\nmain-sequence band. In contrast, stars with masses M > 3 M_sun seem to be\nconcentrated closer to the ZAMS. The study of a few known members of nearby\nopen clusters with accurate Hipparcos parallaxes confirms these conclusions.\nStronger magnetic fields tend to be found in hotter, younger and more massive\nstars, as well as in stars with shorter rotation periods. No evidence is found\nfor any loss of angular momentum during the main-sequence life. The magnetic\nflux remains constant over the stellar life time on the main sequence. An\nexcess of stars with large obliquities beta is detected in both higher and\nlower mass stars. The obliquity angle distribution as inferred from the\ndistribution of r-values appears random at the time magnetic stars become\nobservable on the H-R diagram. After quite a short time spent on the main\nsequence, the obliquity angle beta tends to reach values close to either 90 deg\nor 0 deg for M < 3 M_sun. The evolution of the obliquity angle beta seems to be\nsomewhat different for low and high mass stars. While we find a strong hint for\nan increase of beta with the elapsed time on the main sequence for stars with M\n> 3 M_sun, no similar trend is found for stars with M < 3 M_sun. However, the\npredominance of high values of beta at advanced ages in these stars is notable.", "We study theoretically the stability of flow in superfluid 3He-A. The\ncalculations are done using a one-dimensional model where the order parameter\ndepends only on the coordinate in the direction of the superfluid velocity v_s.\nWe concentrate on the case that the external magnetic field H is perpendicular\nto v_s, where only few results are available analytically. We calculate the\ncritical velocity v_c at which the superflow becomes unstable against the\nformation of continuous vortices. The detailed dependence of v_c on the\ntemperature and on the form of the underlying orbital texture l(r) is\ninvestigated. Both uniform and helical textures and two types of domain-wall\nstructures are studied. The results are partially in agreement with experiments\nmade in a rotating cylinder.", "We study the problem of two particles with Coulomb repulsion in a\ntwo-dimensional disordered potential in the presence of a magnetic field. For\nthe regime, when without interaction all states are well localized, it is shown\nthat above a critical excitation energy electron pairs become delocalized by\ninteraction. The transition between the localized and delocalized regimes goes\nin the same way as the metal-insulator transition at the mobility edge in the\nthree dimensional Anderson model with broken time reversal symmetry.", "The temperature dependence of the frequencies of a Bose-Einstein condensate\nobtained in experiment has not been fully understood theoretically. In this\npaper we present a simplified version of a two-gas model. A numerically-found\nground state of the system is used for the small-oscillations analysis. In the\ncase of spherical symmetry a full spectrum of frequencies is found for low\norbital quantum numbers. Avoided crossings that appear in the spectrum might be\nthe reason for experimentally observed frequency shifts.", "A problem of the crossover from percolation to diffusion transport is\nconsidered. A general scaling theory is proposed. It introduces\nphenomenologically four critical exponents which are connected by two\nequations. One exponent is completely new. It describes the increase of the\ndiffusion below percolation threshold. As an example, an exact solution of one\ndimensional lattice problem is given. In this case the new exponent $q=2$.", "The tunnel splitting in biaxial antiferromagnetic particles is studied with a\nmagnetic field applied along the hard anisotropy axis. We observe the\noscillation of tunnel splitting as a function of the magnetic field due to the\nquantum phase interference of two tunneling paths of opposite windings. The\noscillation is similar to the recent experimental result with Fe}$_8$\\textrm{\\\nmolecular clusters.}", "Many ground state studies of $^4$He using a shadow wave function with an\ninverse fifth power McMillan particle-particle correlation function have\nyielded radial distribution functions with misplaced peaks. It has been\nconjectured that this is due to the specific choice of the McMillan correlation\nfunction. However, beyond the use of fully optimized two-particle correlation\nfunctions, there has been little study of simple alternatives that can correct\nthis defect. In this work we show that the remedy is surprisingly simple. When\na shadow wavefunction with an inverse seventh power particle-particle\ncorrelation function is used to study $^4$He, it gives a correctly peaked\nradial distribution function, lowers the energy at all liquid and solid\ndensities, and produces an excellent equation of state.", "Using a large galaxy group catalogue based on the Sloan Digital Sky Survey\nData Release 4 we measure three different types of intrinsic galaxy alignment\nwithin groups: halo alignment between the orientation of the brightest group\ngalaxies (BGG) and the distribution of its satellite galaxies, radial alignment\nbetween the orientation of a satellite galaxy and the direction towards its\nBGG, and direct alignment between the orientation of the BGG and that of its\nsatellites. In agreement with previous studies we find that satellite galaxies\nare preferentially located along the major axis. In addition, on scales r < 0.7\nRvir we find that red satellites are preferentially aligned radially with the\ndirection to the BGG. The orientations of blue satellites, however, are\nperfectly consistent with being isotropic. Finally, on scales r < 0.1 \\Rvir, we\nfind a weak but significant indication for direct alignment between satellites\nand BGGs. We briefly discuss the implications for weak lensing measurements.", "Aiming at a better understand of the physical and chemical processes in the\nhot molecular core stage of high-mass star formation, we observed the\nprototypical hot core G29.96-0.02 in the 862mu band with the Submillimeter\nArray (SMA) at sub-arcsecond spatial resolution. The observations resolved the\nhot molecular core into six submm continuum sources with the finest spatial\nresolution of 0.36''x0.25'' (~1800AU) achieved so far. Four of them located\nwithin 7800(AU)^2 comprise a proto-Trapezium system with estimated protostellar\ndensities of 1.4x0^5 protostars/pc^3. The plethora of ~80 spectral lines allows\nus to study the molecular outflow(s), the core kinematics, the temperature\nstructure of the region as well as chemical effects. The derived hot core\ntemperatures are of the order 300K. We find interesting chemical spatial\ndifferentiations, e.g., C34S is deficient toward the hot core and is enhanced\nat the UCHII/hot core interface, which may be explained by temperature\nsensitive desorption from grains and following gas phase chemistry. The\nSiO(8-7) emission outlines likely two molecular outflows emanating from this\nhot core region. Emission from most other molecules peaks centrally on the hot\ncore and is not dominated by any individual submm peak. Potential reasons for\nthat are discussed. A few spectral lines that are associated with the main\nsubmm continuum source, show a velocity gradient perpendicular to the\nlarge-scale outflow. Since this velocity structure comprises three of the\ncentral protostellar sources, this is not a Keplerian disk. While the data are\nconsistent with a gas core that may rotate and/or collapse, we cannot exclude\nthe outflow(s) and/or nearby expanding UCHII region as possible alternative\ncauses of this velocity pattern.", "We propose a method to reach conditions of high degeneracy in a trapped Fermi\ngas, based on the adiabatic transfer of atoms from a magnetic to a tighter\noptical trap. The transformation yields a large increase of the Fermi energy,\nwithout a significant change of the temperature. The large enhancement of the\ncentral density emphasizes the role of the interactions and makes the system\nmuch closer to the BCS transition. An estimate of the time needed to achieve\nthe conditions of adiabaticity is also given.", "We present the analysis of the source counts in the XMM-COSMOS survey using\ndata of the first year of XMM-Newton observations. The survey covers ~2 deg^2\nwithin the region of sky bounded by 9^h57.5^m<R.A.<10^h03.5^m;\n1^d27.5^m<DEC<2^d57.5^m with a total net integration time of 504 ks. Using a\nmaximum likelihood algorithm we detected a total of 1390 sources at least in\none band. Using Monte Carlo simulations to estimate the sky coverage we\nproduced the logN-logS relations. These relations have been then derived in the\n0.5--2 keV, 2--10 keV and 5--10 keV energy bands, down to flux limits of\n7.2x10^-16 erg cm^-2 s^-1, 4.0x10^-15 erg cm^-2 s^-1 and 9.7x10^-15 erg cm^-2\ns^-1, respectively. These relations have been compared to previous X-ray survey\nand to the most recent X-ray background model finding an excellent agreement.\nThe slightly different normalizations observed in the source counts of COSMOS\nand previous surveys can be largely explained as a combination of low counting\nstatistics and cosmic variance introduced by the large scale structure.", "We begin by reviewing the theory of thermal, neutrino-driven proto-neutron\nstar (PNS) winds. Including the effects of magnetic fields and rotation, we\nthen derive the mass and energy loss from magnetically-driven PNS winds for\nboth relativistic and non-relativistic outflows, including important\nmulti-dimensional considerations. With these simple analytic scalings we argue\nthat proto-magnetars born with ~ millisecond rotation periods produce\nrelativistic winds just a few seconds after core collapse with luminosities,\ntimescales, mass-loading, and internal shock efficiencies favorable for\nproducing long-duration gamma-ray bursts.", "After the work of Gladman et al. (1998), it is now assessed that many\nirregular satellites are orbiting around Uranus. Despite many studies have been\nperformed in past years, very few is know for the light-curves of these objects\nand inconsistencies are present between colours derived by different authors.\nThis situation motivated our effort to improve both the knowledge of colours\nand light curves. We present and discuss time series observations of Sycorax,\nProspero, Stephano, Setebos and Trinculo, five faint irregular satellites of\nUranus, carried out at VLT, ESO Paranal (Chile) in the nights between 29 and 30\nJuly, 2005 and 25 and 30 November, 2005. We derive light curves for Sycorax and\nProspero and colours for all of these these bodies. For Sycorax we obtain\ncolours B-V =0.839 +/- 0.014, V-R = 0.531 +/- 0.005 and a light curve which is\nsuggestive of a periodical variation with period about 3.6 hours and amplitude\nabout 0.067 +/- 0.004 mag. The periods and colours we derive for Sycorax are in\nagreement with our previous determination in 1999 using NTT. We derive also a\nlight-curve for Prospero which suggests an amplitude of about 0.2 mag and a\nperiodicity of about 4 hours. However, the sparseness of our data, prevents a\nmore precise characterization of the light-curves, and we can not determine\nwether they are one-peaked or two-peaked. Hence, these periods and amplitudes\nhave to be considered preliminary estimates. As for Setebos, Stephano and\nTrinculo the present data do not allow to derive any unambiguous periodicity,\ndespite Setebos displays a significant variability with amplitude about as\nlarge as that of Prospero. Colours for Prospero, Setebos, Stephano and Trinculo\nare in marginal agreement with the literature.", "In this series of lectures we first describe the basic ingredients of\ngalactic chemical evolution and discuss both analytical and numerical models.\nThen we compare model results for the Milky Way, Dwarf Irregulars, Quasars and\nthe Intra-Cluster- Medium with abundances derived from emission lines. These\ncomparisons allow us to put strong constraints on the stellar nucleosynthesis\nand the mechanisms of galaxy formation.", "We discuss Bose-Einstein condensation in a trapped gas of bosonic particles\ninteracting dominantly via dipole-dipole forces. We find that in this case the\nmean-field interparticle interaction and, hence, the stability diagram are\ngoverned by the trapping geometry. Possible physical realisations include\nultracold heteronuclear molecules, or atoms with laser induced electric dipole\nmoments.", "In 1985, Beeman, Tsu and Thorpe established an almost linear relation between\nthe Raman transverse-optic (TO) peak width and the spread in mean bond angle in\na-Si. This relation is often used to estimate the latter quantity in\nexperiments. In the last decade, there has been significant progress in the\ncomputer generation of sample networks of amorphous silicon. Exploiting this\nprogress, this manuscript presents a more accurate determination of the\nrelation between the TO peak width and angular spread using 1000-atom\nconfigurations. Also investigated and quantified are the relations between the\nTO peak frequency and the ratio of the intensities of the transverse-acoustic\n(TA) and TO peak, both as functions of the angular spread. As this spread\ndecreases, the TA/TO intensity ratio decreases and the TO peak frequency\nincreases. These relations offer additional ways to obtain structural\ninformation on a-Si from Raman measurements.", "(abridged) The soft excess seen in the X-ray spectra of many high mass\naccretion rate AGN can be well modelled by reflection from a partially ionised\naccretion disc. However, the derived parameters are often extreme, both in\nterms of the underlying spacetime and the reflection geometry, and these models\nrequire that the disc is far from hydrostatic equilibrium. An alternative model\nuses similarly partially ionised, velocity smeared material but seen in\nabsorption, though again the derived velocities are extreme, requiring magnetic\ndriving (in the jet?) rather than a simple line driven disc wind. We find that\nwhile both models give comparably good fits to XMM--Newton data, we favour the\nabsorption model as, unlike reflection, all the derived spectral indices are\nsoft. This is as expected by analogy with the correspondingly high mass\naccretion rate stellar mass black holes. Furthermore, these X-ray spectra are\nconsistent with a one--to--one mapping between AGN type and spectral state,\nwith NLS1's having softer spectra corresponding to the very high state, while\nthe broad line AGN have Gamma~2 as expected for the high/soft state. We also\nuse the simultaneous OM data to derive the ratio of disc to total accretion\npower which is another tracer of spectral state in X-ray binaries. This does\nnot always show that the disc in NLS1's contributes less than 80 per cent of\nthe total power, as expected for a very high state. We suggest that this is an\nartifact of the standard disc models used to determine the disc luminosity in\nour fits. The disc seen in the very high state of black hole binaries is often\nobserved to be distorted from the standard shape, and a similar effect in\nNLS1's could recover the correspondance between black hole binary spectral\nstate and AGN type.", "We study the dynamic process of splitting a condensate by raising a potential\nbarrier in the center of a harmonic trap. We use a two-mode model to describe\nthe phase coherence between the two halves of the condensate. Furthermore, we\nexplicitly consider the spatial dependence of the mode funtions, which varies\ndepending on the potential barrier. This allows to get the tunneling coupling\nbetween the two wells and the on-site energy as a function of the barrier\nheight. Moreover we can get some insight on the collective modes which are\nexcited by raising the barrier. We describe the internal and external degrees\nof freedom by variational ansatz. We distinguish the possible regimes as a\nfunction of the characteristic parameters of the problem and identify the\nadiabaticity conditions.", "We present an Ha spectral observation of a Balmer-dominated shock on the\neastern side of Tycho's supernova remnant using the Subaru Telescope. Utilizing\nthe High Dispersion Spectrograph (HDS), we measure the spatial variation of the\nline profile between preshock and postshock gas. Our observation clearly shows\na broadening and centroid shift of the narrow-component postshock Ha line\nrelative to the Ha emission from the preshock gas. The observation supports the\nexistence of a thin precursor where gas is heated and accelerated ahead of the\nshock. Furthermore, the spatial profile of the emission ahead of the Balmer\nfilament shows a gradual gradient in the Ha intensity and line width ahead of\nthe shock. We propose that this region (~10^16 cm) is likely to be the\nspatially resolved precursor. The line width increases from ~30 up to ~45 km/s,\nand its central velocity shows a redshift of ~5 km/s across the shock front.\nThe characteristics of the precursor are consistent with a cosmic-ray\nprecursor, although the possibility of a fast neutral precursor is not ruled\nout.", "The polaron energy and the effective mass are calculated for an electron\nconfined in a finite quantum well constructed of $GaAs/Al_x Ga_{1-x} As$\nlayers. To simplify the study we suggest a model in which parameters of a\nmedium are averaged over the ground-state wave function. The rectangular and\nthe Rosen-Morse potential are used as examples.\n  To describe the confined electron properties explicitly to the second order\nof perturbations in powers of the electron-phonon coupling constant we use the\nexact energy-dependent Green function for the Rosen-Morse confining potential.\nIn the case of the rectangular potential, the sum over all intermediate virtual\nstates is calculated. The comparison is made with the often used leading term\napproximation when only the ground-state is taken into account as a virtual\nstate. It is shown that the results are quite different, so the incorporation\nof all virtual states and especially those of the continuous spectrum is\nessential.\n  Our model reproduces the correct three-dimensional asymptotics at both small\nand large widths. We obtained a rather monotonous behavior of the polaron\nenergy as a function of the confining potential width and found a peak of the\neffective mass. The comparison is made with theoretical results by other\nauthors. We found that our model gives practically the same (or very close)\nresults as the explicit calculations for potential widths $L \\geq 10 \\AA$.", "We explain for the first time thermopower data for p-type GaAs/AlGaAs layers.\nThe data span a temperature range between 0.2 to 1.2K. We calculate both the\ndiffusion $S^{d}$ and the phonon-drag $S^{g}$ contributions to the thermopower.\nWe find that $S^{d}$ is significant for temperatures up to 0.3K while at higher\ntemperatures $S^{g}$ dominates. The calculated and measured $S^{g}$ agree very\nwell with no adjustable parameters.", "We investigate, using numerical simulations and analytical arguments, a\nsimple one dimensional model for the swelling or the collapse of a closed\npolymer chain of size N, representing the dynamical evolution of a polymer in a\n\\Theta-solvent that is rapidly changed into a good solvent (swelling) or a bad\nsolvent (collapse). In the case of swelling, the density profile for\nintermediate times is parabolic and expands in space as t^{1/3}, as predicted\nby a Flory-like continuum theory. The dynamics slows down after a time \\propto\nN^2 when the chain becomes stretched, and the polymer gets stuck in metastable\n`zig-zag' configurations, from which it escapes through thermal activation. The\nsize of the polymer in the final stages is found to grow as \\sqrt{\\ln t}. In\nthe case of collapse, the chain very quickly (after a time of order unity)\nbreaks up into clusters of monomers (`pearls'). The evolution of the chain then\nproceeds through a slow growth of the size of these metastable clusters, again\nevolving as the logarithm of time. We enumerate the total number of metastable\nstates as a function of the extension of the chain, and deduce from this\ncomputation that the radius of the chain should decrease as 1/\\ln(\\ln t). We\ncompute the total number of metastable states with a given value of the energy,\nand find that the complexity is non zero for arbitrary low energies. We also\nobtain the distribution of cluster sizes, that we compare to simple\n`cut-in-two' coalescence models. Finally, we determine the aging properties of\nthe dynamical structure. The subaging behaviour that we find is attributed to\nthe tail of the distribution at small cluster sizes, corresponding to\nanomalously `fast' clusters (as compared to the average). We argue that this\nmechanism for subaging might hold in other slowly coarsening systems.", "We report the occurrence of quenching and annealing in a version of the\nMinority Game (MG) in which the winning option is to join a given fraction of\nthe population that is a free, external parameter. We compare this to the\ndifferent dynamics of the Bar Attendance Model (BAM) where the updating of the\nattendance strategy makes use of all available information about the system and\nquenching does not occur. We provide an annealing schedule by which the\nquenched configuration of the MG reaches equilibrium and coincides with the one\nobtained with the BAM", "Spectral diagnostic features formed in the solar chromosphere are few and\ndifficult to interpret -- they are neither formed in the optically thin regime\nnor in local thermodynamic equilibrium (LTE). To probe the state of the\nchromosphere, both from observations and theory, it is therefore necessary with\nmodeling. I discuss both traditional semi-empirical modeling, numerical\nexperiments illustrating important ingredients necessary for a self-consistent\ntheoretical modeling of the solar chromosphere and the first results of such\nmodels.", "We compare the efficiency of four-wave mixing in quantum degenerate gases of\nbosonic and fermionic atoms. It is shown that matter-wave gratings formed from\neither bosonic or fermionic atoms can in principle exhibit nearly identical\nBragg-scattering, i.e. four-wave mixing, properties. This implies that effects\nsuch as coherent matter-wave amplification and superradiance can occur in\ndegenerate fermi gases. While in the boson case the Bragg resonance is clearly\ndue to `Bose enhancement', in the case of fermions the resonance is due to\nconstructive many-particle quantum interference.", "context : Unlike silicon and calcium, sulphur is an alpha-element which does\nnot form dust. Some of the available observations of the evolution of sulphur\nwith metallicity indicate an increased scatter of sulphur to iron ratios at low\nmetallicities or even a bimodal distribution, with some stars showing constant\nS/Fe at all metallicities and others showing an increasing S/Fe ratio with\ndecreasing metallicity. In metal-poor stars SI lines of Multiplet 1 at 920 nm\nare not yet too weak to permit to measure the sulphur abundance A(S), however\nin ground-based observations they are severely affected by telluric lines. aims\n: We investigate the possibility to measure sulphur abundances from SI Mult. 3\nat 1045 nm lines, which lie in the near infra-red. These are slightly weaker\nthan those of Mult. 1, but lie in a range not affected by telluric lines.\nmethod We investigate the lines of Mult.3 in the Sun (G2V), Procyon (F5V), HD\n33256 (F5V), HD 25069 (G9V) and epsilon Eri (HD 22049, K2V). For the Sun and\nProcyon the analysis has been performed with CO5BOLD 3D hydrodynamical model\natmospheres, for the other three stars, for which hydrodynamical simulations\nare not available, the analysis has been performed using 1D model atmospheres.\nresults For our sample of stars we find a global agreement of A(S) from lines\nof different multiplets. conclusions : Our results suggest that the infrared\nlines of Mult. 3 are a viable indicator of the sulphur abundance which, because\nof the intrinsic strength of this multiplet, should be suitable to study the\ntrend of [S/Fe] at low metallicities.", "We present the first high-resolution, ground-based observations of HCN and\nC2H2 toward the T Tauri binary star system GV Tau. We detected strong\nabsorption due to HCN nu_3 and weak C2H2 (nu_3 and nu_2 + (nu_4 + nu_5)^0_+)\nabsorption toward the primary (GV Tau S) but not the infrared companion. We\nalso report CO column densities and rotational temperatures, and present\nabundances relative to CO of HCN/CO ~0.6% and C2H2/CO ~1.2% and an upper limit\nfor CH4/CO < 0.37% toward GV Tau S. Neither HCN nor C2H2 were detected toward\nthe infrared companion and results suggest that abundances may differ between\nthe two sources.", "A space-based gravitational microlensing exoplanet survey will provide a\nstatistical census of exoplanets with masses down to 0.1 Earth-masses and\norbital separations ranging from 0.5AU to infinity. This includes analogs to\nall the Solar System's planets except for Mercury, as well as most types of\nplanets predicted by planet formation theories. Such a survey will provide\nresults on the frequency of planets around all types of stars except those with\nshort lifetimes. Close-in planets with separations < 0.5 AU are invisible to a\nspace-based microlensing survey, but these can be found by Kepler. Other\nmethods, including ground-based microlensing, cannot approach the comprehensive\nstatistics on the mass and semi-major axis distribution of extrasolar planets\nthat a space-based microlensing survey will provide. The terrestrial planet\nsensitivity of a ground-based microlensing survey is limited to the vicinity of\nthe Einstein radius at 2-3 AU, and space-based imaging is needed to identify\nand determine the mass of the planetary host stars for the vast majority of\nplanets discovered by microlensing. Thus, a space-based microlensing survey is\nlikely to be the only way to gain a comprehensive understanding of the nature\nof planetary systems, which is needed to understand planet formation and\nhabitability. The proposed Microlensing Planet Finder (MPF) mission is an\nexample of a space-based microlensing survey that can accomplish these\nobjectives with proven technology and a cost that fits comfortably under the\nNASA Discovery Program cost cap.", "In experiments conducted recently at MIT on Na Bose-Einstein condensates [S.\nInouye et al, Nature 392, 151 (1998); J. Stenger et al, Phys. Rev. Lett. 82,\n2422 (1999)], large loss rates were observed when a time-varying magnetic field\nwas used to tune a molecular Feshbach resonance state near the state of a pair\nof atoms in the condensate. A collisional deactivation mechanism affecting a\ntemporarily formed molecular condensate [see V. A. Yurovsky, A. Ben-Reuven, P.\nS. Julienne and C. J. Williams, Phys. Rev. A 60, R765 (1999)], studied here in\nmore detail, accounts for the results of the slow-sweep experiments. A best fit\nto the MIT data yields a rate coefficient for deactivating atom-molecule\ncollisions of 1.6e-10 cm**3/s. In the case of the fast sweep experiment, a\nstudy is carried out of the combined effect of two competing mechanisms, the\nthree-atom (atom-molecule) or four-atom (molecule-molecule) collisional\ndeactivation vs. a process of two-atom trap-state excitation by curve crossing\n[F. H. Mies, P. S. Julienne, and E. Tiesinga, Phys. Rev. A 61, 022721 (2000)].\nIt is shown that both mechanisms contribute to the loss comparably and\nnonadditively.", "We simulate in the mean-field limit the effects of rotationally stirring a\nthree-dimensional trapped Bose-Einstein condensate with a Gaussian laser beam.\nA single vortex cycling regime is found for a range of trap geometries, and is\nwell described as coherent cycling between the ground and the first excited\nvortex states. The critical angular speed of stirring for vortex formation is\nquantitatively predicted by a simple model. We report preliminary results for\nthe collisions of vortex lines, in which sections may be exchanged.", "While the diagonalization of a quadratic bosonic form can always be done\nusing a Bogoliubov transformation, the practical implementation for systems\nwith a large number of different bosons is a tedious analytical task. Here we\nuse the coupled cluster method (CCM) to exactly diagonalise such complicated\nquadratic forms. This yields to a straightforward algorithm which can easily be\nimplemented using computer algebra even for a large number of different bosons.\nWe apply this method on a Heisenberg system with two interpenetrating square\nlattice antiferromagnets, which is a model for the quasi 2D antiferromagnet\nBa_2Cu_3O_4Cl_2. Using a four-magnon spin wave approximation we get a\ncomplicated Hamiltonian with four different bosons, which is treated with CCM.\nResults are presented for magnetic ground state correlations.", "Above a critical velocity, the dominant mechanism of energy transfer between\na moving object and a dilute Bose-Einstein condensate is vortex formation. In\nthis paper, we discuss the critical velocity for vortex formation and the link\nbetween vortex shedding and drag in both homogeneous and inhomogeneous\ncondensates. We find that at supersonic velocities sound radiation also\ncontributes significantly to the drag force.", "Experimental methods allow the shape and chemical composition of solid\nsurfaces to be controlled at a mesoscopic level. Exposing such structured\nsubstrates to a gas close to coexistence with its liquid can produce quite\ndistinct adsorption characteristics compared to that occuring for planar\nsystems, which may well play an important role in developing technologies such\nas super-repellent surfaces or micro-fluidics. Recent studies have concentrated\non adsorption of liquids at rough and heterogeneous substrates and the\ncharacterisation of nanoscopic liquid films. However, the fundamental effect of\ngeometry has hardly been addressed. Here we show that varying the shape of the\nsubstrate can exert a profound influence on the adsorption isotherms allowing\nus to smoothly connect wetting and capillary condensation through a number of\nnovel and distinct examples of fluid interfacial phenomena. This opens the\npossibility of tailoring the adsorption properties of solid substrates by\nsculpturing their surface shape.", "We calculate the very high energy (sub-GeV to TeV) inverse Compton emission\nof GRB afterglows. We argue that this emission provides a powerful test of the\ncurrently accepted afterglow model. We focus on two processes: synchrotron\nself-Compton (SSC) emission within the afterglow blast wave, and external\ninverse Compton (EIC) emission which occurs when flare photons (produced by an\ninternal process) pass through the blast wave. We show that if our current\ninterpretations of the Swift XRT data are correct, there should be a canonical\nhigh energy afterglow emission light curve. Our predictions can be tested with\nhigh energy observatories such as GLAST, Whipple, H.E.S.S. and MAGIC. Under\nfavorable conditions we expect afterglow detections in all these detectors.", "We present a technique to calculate the transport properties through\none-dimensional models of molecular wires. The calculations include inelastic\nelectron scattering due to electron-lattice interaction. The coupling between\nthe electron and the lattice is crucial to determine the transport properties\nin one-dimensional systems subject to Peierls transition since it drives the\ntransition itself. The electron-phonon coupling is treated as a quantum\ncoherent process, in the sense that no random dephasing due to electron-phonon\ninteractions is introduced in the scattering wave functions. We show that\ncharge carrier injection, even in the tunneling regime, induces lattice\ndistortions localized around the tunneling electron. The transport in the\nmolecular wire is due to polaron-like propagation. We show typical examples of\nthe lattice distortions induced by charge injection into the wire. In the\ntunneling regime, the electron transmission is strongly enhanced in comparison\nwith the case of elastic scattering through the undistorted molecular wire. We\nalso show that although lattice fluctuations modify the electron transmission\nthrough the wire, the modifications are qualitatively different from those\nobtained by the quantum electron-phonon inelastic scattering technique. Our\nresults should hold in principle for other one-dimensional atomic-scale wires\nsubject to Peierls transitions.", "In a previous work, we showed that the differentially rotating equatorial\ndisk in the pulsar's electrosphere is diocotron unstable in the\nnon-relativistic regime. In this paper, we extend these results and study the\nrelativistic and electromagnetic stabilisation effects by including the\nmagnetic field perturbation and allow for relativistic speeds of the guiding\ncentre, in a self-consistent manner. We use the electric drift approximation,\nvalid for low-density plasmas.\n  We linearise the coupled relativistic cold-fluid and Maxwell equations in the\nelectric drift approximation. The non-linear eigenvalue problem for the\nperturbed azimuthal electric field is solved numerically with standard technics\nfor boundary value problems like the shooting method. The spectrum of the\nrelativistic diocotron instability in a non-neutral plasma column confined\nbetween two cylindrically conducting walls is computed.\n  For low-speed motions, we recover the eigenfunctions and eigenspectra of the\nnon-relativistic diocotron instability. Our algorithm is also checked in the\nrelativistic planar diode geometry for which an analytical expression of the\ndispersion relation is known. As expected, when the relativistic and\nelectromagnetic effects become significant, the diocotron instability tends to\nstabilise. In cylindrical geometry, for some special rotation profile, all\nazimuthal modes $l$ are completely suppressed for sufficiently relativistic\nflows. However, for the profile relevant to the electrosphere, depending on the\nexact rotation curves, the growth rates can either significantly decrease till\nthey vanish or persist for moderate $l$.", "We are discussing Schwinger'idea that physical mechanism of sonoluminescence\nis a physical vacuum excitation. This theory was based on the assumption that\nthe sudden change of the rate of bubble collapse leads to the jump of\ndielectric constant of the gas trapped inside the bubble. We show that the\ndependence of the dielectric constant on the gas density really leads to the\njump of the dielectric constant at shock-wave propagation in a collapsing gas\nbubble.", "The density of states of the ideal three-dimensional Penrose tiling, a\nquasicrystalline model, is calculated with a resolution of 10 meV. It is not\nspiky. This falsifies theoretical predictions so far, that spikes of width\n10-20 meV are generic for the density of states of quasicrystals, and it\nconfirms recent experimental findings. The qualitative difference between our\nresults and previous calculations is partly explained by the small number of k\npoints that has usually been included in the evaluation of the density of\nstates of periodic approximants of quasicrystals. It is also shown that both\nthe density of states of a small approximant of the three-dimensional Penrose\ntiling and the density of states of the ideal two-dimensional Penrose tiling do\nhave spiky features, which also partly explains earlier predictions.", "A microscopical theory of electronic spectrum and superconductivity is\nformulated within the two-dimensional anisotropic t-J model with t_{x}\\neq\nt_{y} and J_{x}\\neq J_{y}. Renormalization of electronic spectrum and\nsuperconductivity mediated by spin-fluctuations are investigated within the\nEliashberg equation in the weak coupling approximation. The gap function has\nd+s symmetry with the extended s-wave component being proportional to the\nasymmetry t_{y} - t_{x}. Some experimental consequences of the obtained results\nare discussed.", "Although the rocket-based X-ray Quantum Calorimetry (XQC) experiment was\ndesigned for X-ray spectroscopy, the minimal shielding of its calorimeters, its\nlow atmospheric overburden, and its low-threshold detectors make it among the\nmost sensitive instruments for detecting or constraining strong interactions\nbetween dark matter particles and baryons. We use Monte Carlo simulations to\nobtain the precise limits the XQC experiment places on spin-independent\ninteractions between dark matter and baryons, improving upon earlier analytical\nestimates. We find that the XQC experiment rules out a wide range of\nnucleon-scattering cross sections centered around one barn for dark matter\nparticles with masses between 0.01 and 10^5 GeV. Our analysis also provides new\nconstraints on cases where only a fraction of the dark matter strongly\ninteracts with baryons.", "We consider non centered vortices and their arrays in a cylindrically trapped\nBose-Einstein condensate at zero temperature. We study the kinetic energy and\nthe angular momentum per particle in the Thomas Fermi regime and their\ndependence on the distance of the vortices from the center of the trap. Using a\nperturbative approach with respect to the velocity-field of the vortices, we\ncalculate to first order the frequency shift of the collective low-lying\nexcitations due to the presence of an off-center vortex or a vortex array, and\ncompare these results with predictions which would be obtained by the\napplication of a simple sum-rule approach, previously found to be very\nsuccessful for centered vortices. It turns out that the simple sum-rule\napproach fails for off-centered vortices.", "We present Gemini optical spectroscopy of 23 young star clusters in NGC3256.\nWe find that the cluster ages range are from few Myr to ~150 Myr. All these\nclusters are relatively massive (2--40)x 10^{5} \\msun$ and appear to be of\nroughly 1.5 \\zo metallicity. The majority of the clusters in our sample follow\nthe same rotation curve as the gas and hence were presumably formed in the\nmolecular-gas disk. However, a western subsample of five clusters has\nvelocities that deviate significantly from the gas rotation curve. These\nclusters may either belong to the second spiral galaxy of the merger or may\nhave formed in tidal-tail gas falling back into the system. We discuss our\nobservations in light of other known cluster populations in merging galaxies,\nand suggest that NGC 3256 is similar to Arp 220, and hence may become an\nUltra-luminous Infrared Galaxy as the merger progresses and the star-formation\nrate increases.\n  Some of the clusters which appeared as isolated in our ground-based images\nare clearly resolved into multiple sub-components in the HST-ACS images. The\nsame effect has been observed in the Antennae galaxies, showing that clusters\nare often not formed in isolation, but instead tend to form in larger groups or\ncluster complexes.", "We present a detailed analysis of the Galaxy Stellar Mass Function of\ngalaxies up to z=2.5 as obtained from the VVDS. We estimate the stellar mass\nfrom broad-band photometry using 2 different assumptions on the galaxy star\nformation history and show that the addition of secondary bursts to a\ncontinuous star formation history produces systematically higher (up to 40%)\nstellar masses. At low redshift (z=0.2) we find a substantial population of\nlow-mass galaxies (<10^9 Msun) composed by faint blue galaxies (M_I-M_K=0.3).\nIn general the stellar mass function evolves slowly up to z=0.9 and more\nsignificantly above this redshift. Conversely, a massive tail is present up to\nz=2.5 and have extremely red colours (M_I-M_K=0.7-0.8). We find a decline with\nredshift of the overall number density of galaxies for all masses (59+-5% for\nM>10^8 Msun at z=1), and a mild mass-dependent average evolution\n(`mass-downsizing'). In particular our data are consistent with mild/negligible\n(<30%) evolution up to z=0.7 for massive galaxies (>6x10^10 Msun). For less\nmassive systems the no-evolution scenario is excluded. A large fraction (>=50%)\nof massive galaxies have been already assembled and converted most of their gas\ninto stars at z=1, ruling out the `dry mergers' as the major mechanism of their\nassembly history below z=1. This fraction decreases to 33% at z=2. Low-mass\nsystems have decreased continuously in number and mass density (by a factor up\nto 4) from the present age to z=2, consistently with a prolonged mass assembly\nalso at z<1.", "We have carried out a comparative statistical study for the displacement of\nthe Sun from the Galactic plane (z_\\odot) following three different methods.\nThe study has been done using a sample of 537 young open clusters (YOCs) with\nlog(Age) < 8.5 lying within a heliocentric distance of 4 kpc and 2030 OB stars\nobserved up to a distance of 1200 pc, all of them have distance information. We\ndecompose the Gould Belt's member in a statistical sense before investigating\nthe variation in the z_\\odot estimation with different upper cut-off limits in\nthe heliocentric distance and distance perpendicular to the Galactic plane. We\nfound z_\\odot varies in a range of ~ 13 - 20 pc from the analys is of YOCs and\n~ 6 - 18 pc from the OB stars. A significant scatter in the z_\\odot obtained\ndue to different cut-off values is noticed for the OB stars although no such\ndeviation is seen for the YOCs. We also determined scale heights of\n56.9(+3.8)(-3.4} and 61.4(+2.7)(-2.4) pc for the distribution of YOCs and OB\nstars respectively.", "New facilities and technologies have advanced our understanding of massive\nstars significantly over the past 30 years. Here I introduce a new large survey\nof massive stars using VLT-FLAMES, noting the target fields and observed binary\nfractions. These data have been used for the first empirical test of the\nmetallicity dependence of the intensity of stellar winds, finding good\nagreement with theory -- an important result for the evolutionary models that\nare used to interpret distant clusters, starbursts, and star-forming galaxies.\nLooking ahead, plans for future Extremely Large Telescopes (ELTs) are now\nundergoing significant development, and offer the exciting prospect of\nobserving spatially-resolved massive stars well beyond the Local Group.", "We report the effect of interstitial fluid on the extent of segregation by\nimaging the pile that results after bidisperse color-coded particles are poured\ninto a silo. Segregation is sharply reduced and preferential clumping of small\nparticles is observed when a small volume fraction of fluid $V_f$ is added. We\nfind that viscous forces in addition to capillary forces have an important\neffect on the extent of segregation $s$ and the angle of repose $\\theta$. We\nshow that the sharp initial change and the subsequent saturation in $s$ and\n$\\theta$ occurs over similar $V_f$. We also find that a transition back to\nsegregation can occur when the particles are completely immersed in a fluid at\nlow viscosities.", "To study the effects of galactic winds on the stellar metallicity\ndistributions and on the evolution of Draco and Ursa Minor dwarf spheroidal\ngalaxies, we compared the predictions of several chemical evolution models,\nadopting different prescriptions for the galactic winds, with the\nphotometrically-derived stellar metallicity distributions of both galaxies. The\nchemical evolution models for Draco and Ursa Minor, which are able to reproduce\nseveral observational features of these two galaxies, such as the several\nabundance ratios, take up-to-date nucleosynthesis into account for\nintermediate-mass stars and supernovae of both types, as well as the effect of\nthese objects on the energetics of the systems. For both galaxies, the model\nthat best fits the data contains an intense continuous galactic wind, occurring\nat a rate proportional to the star formation rate. Models with a wind rate\nassumed to be proportional only to the supernova rate also reproduce the\nobserved SMD, but do not match the gas mass, whereas the models with no\ngalactic winds fail to reproduce the observed SMDs. In the case of Ursa Minor,\nthe same model as in previous works reproduces the observed distribution very\nwell with no need to modify the main parameters of the model. The model for\nDraco, on the other hand, is slightly modified. The observed SMD requires a\nmodel with a lower supernova type Ia thermalization efficiency ($\\eta_{SNeIa}$\n= 0.5 instead of $\\eta_{SNeIa}$ = 1.0) in order to delay the galactic wind,\nwhereas all the other parameters are kept the same. The model results, compared\nto observations, strongly suggest that intense and continuous galactic winds\nplay a very important role in the evolution of local dSphs.", "We obtain the disorder averaged (critical) four-point correlation functions\nfor N species of (two-dimensional Euclidean) Dirac fermions subject to a\n(Gaussian) random su(N) gauge field. The replica approach and the strong\ndisorder approach yield identical results, as one might expect in the light of\nrecent developments in the N=2 case [1]. We establish a connection with\n`dressed' Z_N twist fields in the c=-2 logarithmic conformal field theory\n(LCFT), thereby extending the recent connection to `dressed' Z_2 twists [1,2].\nWe draw attention to the fact that `dressed' Z_2 twist operators have\npreviously appeared in the description of half flux-quantum quasiholes in the\nbulk excitations of the Haldane--Rezayi Quantum Hall state [3].", "The ideas of dynamical complexity induced intermittent turbulence by sporadic\nlocalized interactions of coherent structures are discussed. In particular, we\naddress the phenomenon of magnetic reconfiguration due to coarse-grained\ndissipation as well as the interwoven connection between criticality and\nmultifractal processes. Specific examples are provided.", "We show that the surface gravity of a transiting extrasolar planet can be\ncalculated from only the spectroscopic orbit of its parent star and the\nanalysis of its transit light curve. This does not require additional\nconstraints, such as are often inferred from theoretical stellar models or\nmodel atmospheres. The planet's surface gravity can therefore be measured\nprecisely and from only directly observable quantities. We outline the method\nand apply it to the case of the first known transiting extrasolar planet, HD\n209458b. We find a surface gravity of g_p = 9.28 +/- 0.15 m/s, which is an\norder of magnitude more precise than the best available measurements of its\nmass, radius and density. This confirms that the planet has a much lower\nsurface gravity that that predicted by published theoretical models of gas\ngiant planets. We apply our method to all fourteen known transiting extrasolar\nplanets and find a significant correlation between surface gravity and orbital\nperiod, which is related to the known correlation between mass and period. This\ncorrelation may be the underlying effect as surface gravity is a fundamental\nparameter in the evaporation of planetary atmospheres.", "The magnetic properties of anisotropic films have been studied using\n3D-neutron polarization analysis. The experimental facts refer to essential\ndistinction of the sample states, magnetized in opposite directions. For an\nexplanation of asymmetrical effects the model is offered, in which the\nfundamental theoretical principles of structural phase transitions are used.", "We study the generation of vortices in rotating Bose--Einstein condensates, a\nsituation which has been realized in a recent experiment (K. W. Madison, F.\nChevy, W. Wohlleben, J. Dalibard, Phys. Rev. Lett. {\\bf 84} 806 (2000)). By\ncombining a linear stability analysis with the global optimization of the\nnonlinear free energy functional, we study the regimes that can be reached in\ncurrent experiments. We find a hysteresis phenomenon in the vortex nucleation\ndue to the metastabilization of the vortexless condensate. We also prove that\nfor a fast enough rotating trap the ground state of the condensate hosts one or\nmore bent vortex lines.", "We have imaged the enigmatic radio source-I (Orion-I) in the Orion-KL nebula\nwith the VLA at 43 GHz with 34 mas angular resolution. The continuum emission\nis highly elongated and is consistent with that expected from a nearly edge-on\ndisk. The high brightness and lack of strong molecular lines from Orion-I can\nbe used to argue against emission from dust. Collisional ionization and H-minus\nfree-free opacity, as in Mira variables, require a central star with >10^5\nLsun, which is greater than infrared observations allow. However, if\nsignificant local heating associated with accretion occurs, lower total\nluminosities are possible. Alternatively, photo-ionization from an early B-type\nstar and p+/e- bremsstrahlung can explain our observations, and Orion-I may be\nan example of ionized accretion disk surrounding a forming massive star. Such\naccretion disks may not be able to form planets efficiently.", "The aim of this paper is to identify the young protostellar counterparts\nassociated to dust millimeter cores of the Vela Molecular Ridge Cloud D through\nnew IR observations (H_2 narrow-band at 2.12 micron and N broad band at 10.4\nmicron) along with an investigation performed on the existing IR catalogues.\nThe association of mm continuum emission with infrared sources from catalogues\n(IRAS, MSX, 2MASS), JHK data from the literature and new observations, has been\nestablished according to spatial coincidence, infrared colours and spectral\nenergy distributions. Only 7 out of 29 resolved mm cores (and 16 out of the 26\nunresolved ones) do not exhibit signposts of star formation activity. The other\nones are clearly associated with: far-IR sources, H_2 jets or near-IR objects\nshowing a high intrinsic colour excess. The distribution of the spectral\nindices pertaining to the associated sources is peaked at values typical of\nClass I objects, while three objects are signalled as candidates Class 0\nsources. We remark the high detection rate (30%) of H_2 jets driven by sources\nlocated inside the mm-cores. They appear not driven by the most luminous\nobjects in the field, but rather by less luminous objects in young clusters,\ntestifying the co-existence of both low- and intermediate-mass star formation.\nThe presented results reliably describe the young population of VMR-D. However,\nthe statistical evaluation of activity vs inactivity of the investigated cores,\neven in good agreement with results found for other star forming regions, seems\nto reflect the limiting sensitivity of the available facilities rather than any\nproperty intrinsic to the mm-condensations.", "Aims: We present a photometric study of the deeply eclipsing SW Sex-type\nnova-like cataclysmic variable star BH Lyn\n  Methods: Time-resolved V-band CCD photometry was obtained for seven nights\nbetween 1999 and 2004.\n  Results: We determined 11 new eclipse timings of BH Lyn and derived a refined\norbital ephemeris with an orbital period of 0.155875577(14) day. During the\nobservations, BH Lyn was in high-state with V~15.5 mag. The star presents ~1.5\nmag deep eclipses with mean full-width at half-flux of 0.0683(+/-0.0054)P_orb.\n  The eclipse shape is highly variable, even changing form cycle to cycle. This\nis most likely due to accretion disc surface brightness distribution\nvariations, most probably caused by strong flickering. Time-dependent accretion\ndisc self-occultation or variations of the hot spot(s) intensity are also\npossible explanations. Negative superhumps with period of ~0.145 day are\ndetected in two long runs in 2000. A possible connection between SW Sex and\nnegative superhump phenomena through the presence of tilted accretion disc is\ndiscussed, and a way to observationally test this is suggested.", "The influence of surface defects on the critical properties of magnetic films\nis studied for Ising models with nearest-neighbour ferromagnetic couplings. The\ndefects include one or two adjacent lines of additional atoms and a step on the\nsurface. For the calculations, both density-matrix renormalization group and\nMonte Carlo techniques are used. By changing the local couplings at the defects\nand the film thickness, non-universal features as well as interesting crossover\nphenomena in the magnetic exponents are observed.", "We use variational perturbation theory to calculate various universal\namplitude ratios above and below T_c in minimally subtracted phi^4-theory with\nN components in three dimensions. In order to best exhibit the method as a\npowerful alternative to Borel resummation techniques, we consider only to two-\nand three-loops expressions where our results are analytic expressions. For the\ncritical exponents, we also extend existing analytic expressions for two loops\nto three loops.", "An analytical method is advanced for constructing interpolation formulae for\ncomplicated problems of statistical mechanics, in which just a few terms of\nasymptotic expansions are available. The method is based on the self-similar\napproximation theory, being its variant where control functions are defined\nfrom asymptotic crossover conditions. Several examples from statistical physics\ndemonstrate that the suggested method results in rather simple and surprisingly\naccurate formulae.", "We investigate faint radio emission from low- to high-luminosity Active\nGalactic Nuclei (AGN) selected from the Sloan Digital Sky Survey (SDSS). Their\nradio properties are inferred by co-adding large ensembles of radio image\ncut-outs from the FIRST survey, as almost all of the sources are individually\nundetected. We correlate the median radio flux densities against a range of\nother sample properties, including median values for redshift, [OIII]\nluminosity, emission line ratios, and the strength of the 4000A break. We\ndetect a strong trend for sources that are actively undergoing star-formation\nto have excess radio emission beyond the ~10^28 ergs/s/Hz level found for\nsources without any discernible star-formation. Furthermore, this additional\nradio emission correlates well with the strength of the 4000A break in the\noptical spectrum, and may be used to assess the age of the star-forming\ncomponent. We examine two subsamples, one containing the systems with emission\nline ratios most like star-forming systems, and one with the sources that have\ncharacteristic AGN ratios. This division also separates the mechanism\nresponsible for the radio emission (star-formation vs. AGN). For both cases we\nfind a strong, almost identical, correlation between [OIII] and radio\nluminosity, with the AGN sample extending toward lower, and the star-formation\nsample toward higher luminosities. A clearer separation between the two\nsubsamples is seen as function of the central velocity dispersion of the host\ngalaxy. For systems with similar redshifts and velocity dispersions, the\nstar-formation subsample is brighter than the AGN in the radio by an order of\nmagnitude. This underlines the notion that the radio emission in star-forming\nsystems can dominate the emission associated with the AGN.", "We use fractional integrals to generalize the description of hydrodynamic\naccretion in fractal media. The fractional continuous medium model allows the\ngeneralization of the equations of balance of mass density and momentum\ndensity. These make it possible to consider the general case of spherical\nhydrodynamic accretion onto a gravitating mass embedded in a fractal medium.\nThe general nature of the solution is similar to the \"Bondi solution\", but the\naccretion rate may vary substantially and the dependence on central mass may\nchange significantly depending on dimensionality of the fractal medium. The\ntheory shows consistency with the observational data and numerical simulation\nresults for the particular case of accretion onto pre-main-sequence stars.", "The Bragg, Leibfried, and modified Leibfried numbers are defined in the\ncontext of a theory of dislocation-mediated melting, and their values are\ndetermined from the properties of the dislocation ensemble at the melting\ntemperature. The approximate numerical coincidence of the Bragg and modified\nLeibfried numbers is explained. The parameter K in the definition of the\nmodified Leibfried number is shown to be the natural logarithm of the effective\ncoordination number. Our analysis reveals that the Bragg number can be\nconsidered an elemental constant, in contrast to the Leibfried and modified\nLeibfried numbers.", "We study the dynamics of a quantum rotator kicked according to the\nalmost-periodic Fibonacci sequence. A special numerical technique allows us to\ncarry on this investigation for as many as $10^{12}$ kicks. It is shown that\nabove a critical kick strength the excitation of the system is well described\nby regular diffusion, while below this border it becomes anomalous, and\nsub-diffusive. A law for the dependence of the exponent of anomalous\nsub-diffusion on the system parameters is established numerically. The analogy\nbetween these results and quantum diffusion in models of quasi-crystal and in\nthe kicked Harper system is discussed.", "Conditional elimination of degrees of freedom is shown to lead to an exact\nexpression for the rate of turbulent energy dissipation in terms of a\nrenormalized viscosity and a correction. The correction is neglected on the\nbasis of a previous hypothesis [W.D. McComb and C. Johnston, J.Phys.A v33 L15\n(2000)] that there is a range of parameters for which a quasi-stochastic\nestimate is a good approximation to the exact conditional average. This\nhypothesis was tested by a perturbative calculation to second order in the\nlocal Reynolds number, and the Kolmogorov prefactor (taken as a measure of the\nrenormalized dissipation rate) was found to reach a fixed point which was\ninsensitive to initial values of the kinematic viscosity and to values of the\nspatial rescaling factor h in the range 0.4 <= h <= 0.8.", "Scaling behavior of scale-free evolving networks arising in communications,\ncitations, collaborations, etc. areas is studied. We derive universal scaling\nrelations describing properties of such networks and indicate limits of their\nvalidity. We show that main properties of scale-free evolving networks may be\ndescribed in frames of a simple continuous approach. The simplest models of\nnetworks, which growth is determined by a mechanism of preferential linking,\nare used. We consider different forms of this preference and demonstrate that\nthe range of types of preference linking producing scale-free networks is wide.\nWe obtain also scaling relations for networks with nonlinear, accelerating\ngrowth and describe temporal evolution of arising distributions. Size-effects -\ncut-offs of these distributions - implement restrictions for observation of\npower-law dependences. The main characteristic of interest is so-called degree\ndistribution, i.e., distribution of a number of connections of nodes. A scaling\nform of the distribution of links between pairs of individual nodes for the\ngrowing network of citations is also studied. We describe effects that produce\ndifference of nodes. ``Aging'' of nodes changes exponents of distributions.\nAppearence of a single ``strong'' node changes dramatically the degree\ndistribution of a network. If its strength exceeds some threshold value, the\nstrong node captures a finite part of all links of a network. We show that\npermanent random damage of a growing scale-free network - permanent deleting of\nsome links - change radically values of the scaling exponents. We describe the\narising rich phase diagram. Results of other types of permanent damage are\ndescribed.", "We observe a sharp transition from a singular, high-mass mode of star\nformation, to a low-mass dominated mode, in numerical simulations, at a\nmetallicity of 10^-3 Zsolar. We incorporate a new method for including the\nradiative cooling from metals into adaptive mesh-refinement hydrodynamic\nsimulations. Our results illustrate how metals, produced by the first stars,\nled to a transition from the high-mass star formation mode of Pop III stars, to\nthe low-mass mode that dominates today. We ran hydrodynamic simulations with\ncosmological initial conditions in the standard LambdaCDM model, with\nmetallicities, from zero to 10^-2 Zsolar, beginnning at redshift, z = 99. The\nsimulations were run until a dense core forms at the center of a 5 x 10^5\nMsolar dark matter halo, at z ~ 18. Analysis of the central 1 Msolar core\nreveals that the two simulations with the lowest metallicities, Z = 0 and 10^-4\nZsolar, contain one clump with 99% of the mass, while the two with\nmetallicities, Z = 10^-3 and 10^-2 Zsolar, each contain two clumps that share\nmost of the mass. The Z = 10^-3 Zsolar simulation also produced two low-mass\nproto-stellar objects with masses between 10^-2 and 10^-1 Msolar. Gas with Z >=\n10^-3 Zsolar is able to cool to the temperature of the CMB, which sets a lower\nlimit to the minimum fragmentation mass. This suggests that the second\ngeneration stars produced a spectrum of lower mass stars, but were still more\nmassive on average than stars formed in the local universe.", "A cascade model is described based on multiplier distributions determined\nfrom 3D direct numerical simulations (DNS) of turbulent particle laden flows,\nwhich include two-way coupling between the phases at global mass loadings equal\nto unity. The governing Eulerian equations are solved using pseudo-spectral\nmethods on up to 512**3 computional grid points. DNS results for particle\nconcentration and enstrophy at Taylor microscale Reynolds numbers in the range\n34 - 170 were used to directly determine multiplier distributions (PDFs) on\nspatial scales 3 times the Kolmogorov length scale. The width of the PDFs,\nwhich is a measure of intermittency, decreases with increasing mass loading\nwithin the local region where the multipliers are measured. The functional form\nof this dependence is not sensitive to Reynolds numbers in the range\nconsidered. A partition correlation probability is included in the cascade\nmodel to account for the observed spatial anticorrelation between particle\nconcentration and enstrophy. Joint probability distribution functions of\nconcentration and enstrophy generated using the cascade model are shown to be\nin excellent agreement with those derived directly from our 3D simulations.\nProbabilities predicted by the cascade model are presented at Reynolds numbers\nwell beyond what is achievable by direct simulation. These results clearly\nindicate that particle mass loading significantly reduces the probabilities of\nhigh particle concentration and enstrophy relative to those resulting from\nunloaded runs. Particle mass density appears to reach a limit at around 100\ntimes the gas density. This approach has promise for significant computational\nsavings in certain applications.", "An experimental method is proposed which allows the complete determination of\nthe complex reflection coefficient for absorptive media for positive and\nnegative values of the momenta. It makes use of magnetic reference layers and\nis a modification of a recently proposed technique for phase determination\nbased on polarization measurements. The complex reflection coefficient\nresulting from a simulated application of the method is used for a\nreconstruction of the scattering density profiles of absorptive non-magnetic\nmedia by inversion.", "During the epoch of reionization, the formation of radiation sources is\naccompanied by the growth of a H- photodissociating flux. We estimate the\nimpact of this flux on the formation of molecular hydrogen and cooling in the\nfirst galaxies, assuming different types of radiation sources (e.g. Pop II and\nPop III stars, miniquasars). We find that H- photodissociation reduces the\nformation of H2 molecules by a factor of ~1+1000k_s*x/(f_esc*delta), where x is\nthe mean ionized fraction in the IGM, f_esc is the fraction of ionizing photons\nthat escape from their progenitor halos, delta is the local gas overdensity and\nk_s is an order unity constant which depends on the type of radiation source.\nBy the time a significant fraction of the universe becomes ionized, H-\nphotodissociation may significantly reduce the H2 abundance and, with it, the\nprimordial star formation rate, delaying the progress of reionization.", "We discuss the results from the combined IRAC and MIPS c2d Spitzer Legacy\nobservations of the Serpens star-forming region. In particular we present a set\nof criteria for isolating bona fide young stellar objects, YSO's, from the\nextensive background contamination by extra-galactic objects. We then discuss\nthe properties of the resulting high confidence set of YSO's. We find 235 such\nobjects in the 0.85 deg^2 field that was covered with both IRAC and MIPS. An\nadditional set of 51 lower confidence YSO's outside this area is identified\nfrom the MIPS data combined with 2MASS photometry. We describe two sets of\nresults, color-color diagrams to compare our observed source properties with\nthose of theoretical models for star/disk/envelope systems and our own modeling\nof the subset of our objects that appear to be star+disks. These objects\nexhibit a very wide range of disk properties, from many that can be fit with\nactively accreting disks to some with both passive disks and even possibly\ndebris disks. We find that the luminosity function of YSO's in Serpens extends\ndown to at least a few x .001 Lsun or lower for an assumed distance of 260 pc.\nThe lower limit may be set by our inability to distinguish YSO's from\nextra-galactic sources more than by the lack of YSO's at very low luminosities.\nA spatial clustering analysis shows that the nominally less-evolved YSO's are\nmore highly clustered than the later stages and that the background\nextra-galactic population can be fit by the same two-point correlation function\nas seen in other extra-galactic studies. We also present a table of matches\nbetween several previous infrared and X-ray studies of the Serpens YSO\npopulation and our Spitzer data set.", "We have had several talks recently reviewing 11 years of exoplanet\ndiscoveries through radial velocity variations, or from transits, or from\nmicrolensing. More than 200 exoplanets have been found, including some around\npulsars that we do not discuss here.\n  My physical definition for a planet is a roughly spherical, self-gravitating\nbody more massive than 10**26 g formed from the leftover material in a\nprotostellar disk after the protostar forms. Radiation from the protostar\npushes the inner wall of the disk outward. The material agglomerates and forms\nplanets in radial sequence. The outer planets are formed slowly by classical\ndynamical mechanisms acting in the snow zone. Planets have dense cores because\nof agglomeration.\n  Not one of the exoplanets discovered thus far is a planet. They are\ncryptoplanets formed from matter ejected by protostars. When protostars have\nexcessive infall at high latitudes, they partially balance angular momentum\nthrough outflow at the equator as they spin up. The ejected matter is trapped\nin the magnetic torus formed between the star and the disk, like a tokamak. The\ntokamak eventully reconnects and magnetic compression forms self-gravitating\nremnants trapped and compressed by a closed spherical magnetic field,\nspheromaks. Cooled spheromaks are cryptoplanets. They orbit near the star. They\ncan merge with each other or fall into the star or be ejected. They can grow by\naccreting gas. They have a low density core and abundances characteristic of\nthe protostar. Their masses, radii, densities, and orbits are random, and are\ninconsistent with the parameters for planets. They tend to have lower density\nthan planets.", "We consider a SQUID tunneling between 2 nearly degenerate flux states.\nDecoherence caused by paramagnetic and nuclear spins in the low-$T$ limit is\nshown to be much stronger than that from electronic excitations. The\ndecoherence time $\\tau_{\\phi}$ is determined by the linewidth $E_o$ of spin\nbath states, which can be reduced by a correct choice of ring geometry and\nisotopic purification. $E_o$ can be measured in either field sweep or microwave\nabsorption experiments, allowing both a test of the theory and design control.", "We investigate the Jeans instability of a galactic disk embedded in a\ndynamically responsive dark halo. It is shown that the disk-halo system becomes\nnominally Jeans unstable. On small scales the instability is suppressed, if the\nToomre stability index Q_T is higher than a certain threshold, but on large\nscales the Jeans instability sets invariably in. However, using a simple\nself-consistent disk-halo model it is demonstrated that this occurs on scales\nwhich are much larger than the system so that this is indeed only a nominal\neffect. From a practical point of view the Jeans instability of galactic disks\nis not affected by a live dark halo.", "We report point by point measurements below the blocking temperature of the\nmagnetic relaxation of Mn$_{12}$-acetate as a function of magnetic field\napplied along the easy axis of magnetization. Unexpectedly complex structure is\nobserved which we attribute to the effect of higher-order terms of the spin\nHamiltonianon on the tunneling process.", "We analyze the model of an atomic Bose-Einstein condensate (BEC)\nparametrically coupled to a molecular BEC via a photoassociation process. We\nshow that an interplay of nonlinear inter- and intra-species interactions leads\nto the formation of mutually trapped states of a hybrid condensate, which are\nspatially localized even without a trap. The untrapped atomic-molecular\ncondensates with a large number of atoms in either fraction are shown to be\ndynamically stable in the framework of a mean field theory.", "We present an efficient way to compute diagonal and off-diagonal n-point\ncorrelation functions for quantum spin-systems within the loop algorithm. We\nshow that the general rules for the evaluation of these correlation functions\ntake an especially simple form within the framework of directed loops. These\nrules state that contributing loops have to close coherently. As an application\nwe evaluate the specific heat for the case of spin chains and ladders.", "We have extensively mapped a sample of dense molecular clouds (L1512, TMC-1C,\nL1262, Per 7, L1389, L1251E) in lines of HC3N, CH3OH, SO and C^{18}O. We\ndemonstrate that a high degree of chemical differentiation is present in all of\nthe observed clouds. We analyse the molecular maps for each cloud,\ndemonstrating a systematic chemical differentiation across the sample, which we\nrelate to the evolutionary state of the cloud. We relate our observations to\nthe cloud physical, kinematical and evolutionary properties, and also compare\nthem to the predictions of simple chemical models. The implications of this\nwork for understanding the origin of the clumpy structures and chemical\ndifferentiation observed in dense clouds are discussed.", "Superfluid 3He-A displays the largest variety in vortex structure among the\npresently known coherent quantum systems. The experimentally verified\ninformation comes mostly from NMR measurements on the rotating fluid, from\nwhich the order-parameter texture can often be worked out. The various vortex\nstructures differ in the topology of their order-parameter field, in energy,\ncritical velocity, and in their response to temporal variations in the\nexternally applied flow. They require different experimental conditions for\ntheir creation. When the flow is applied in the superfluid state, the structure\nwith the lowest critical velocity is formed. In 3He-A this leads to the various\nforms of continuous (or singularity-free) vorticity. Which particular structure\nis created depends on the externally applied conditions and on the global\norder-parameter texture.", "In this comment I show that the experimental data on quantum diffusion of\n3-He impurities in solid 4-He can be explained using the adopted quasiparticle\ntheory. The contention by E.G. Kisvarsanyi and N.S. Sullivan (KS) in Phys.Rev.B\nv. 48, 16557 (1993) as well as in their Reply (ibid. v. 55, 3989 (1997)) to the\nGrigor'ev's Comment (Phys.Rev. B v. 55, 3987 (1997)) that \"Pushkarov's theory\nof phonon scattering fails to fit the data by very large factors\" is groundless\nand may result from their bad arithmetical error. This means that the\nphonon-impurity scattering mechanism of diffusion is consistent with experiment\nand its neglecting by KS makes their results questionable.", "The small perturbations method has been extensively used for waves scattering\nby rough surfaces. The standard method developped by Rice is difficult to apply\nwhen we consider second and third order of scattered fields as a function of\nthe surface height. Calculations can be greatly simplified with the use of\nreduced Rayleigh equations, because one of the unknown fields can be\neliminated. We derive a new set of four reduced equations for the scattering\namplitudes, which are applied to the cases of a rough conducting surface, and\nto a slab where one of the boundary is a rough surface. As in the\none-dimensional case, numerical simulations show the appearance of enhanced\nbackscattering for these structures.", "Context: The object HS 0922+1333 was visited briefly in 2002 in a mini survey\nof low accretion rate polars (LARPs) in order to test if they undergo high\nluminosity states similar to ordinary polars. On the basis of that short\nobservation the suspicion arose that the object might be an asynchronous polar\n(Tovmassian et al. 2004). The disparity between the presumed orbital and spin\nperiod appeared to be quite unusual. Aims: We performed follow-up observations\nof the object to resolve the problem. Methods: New simultaneous spectroscopic\nand photometric observations spanning several years allowed measurements of\nradial velocities of emission and absorption lines from the secondary star and\nbrightness variations due to synchrotron emission from the primary. Results:\nNew observations show that the object is actually synchronous and its orbital\nand spin period are equal to 4.04 hours. Conclusions: We identify the source of\nconfusion of previous observations to be a high velocity component of emission\nline arousing from the stream of matter leaving L1 point.", "Only the 1/V_max method has been employed so far for observationally\ndetermining the white dwarf luminosity function, whereas for other kind of\nluminosity functions several other methods have been frequently used. Moreover,\nthe procedures to determine the white dwarf luminosity function are not free of\nbiases. These biases have two different origins: they can either be of\nstatistical nature or a consequence of the measurement errors. In a previous\npaper we carried out an in-depth study of the first category of biases for\nseveral luminosity function estimators. In this paper we focus on the biases\nintroduced by the measurement errors and on the effects of the degree of\ncontamination of the input sample used to build the disc white dwarf luminosity\nfunction by different kinematical populations. To assess the extent of these\nbiases we use a Monte Carlo simulator to generate a controlled synthetic\npopulation and analyse the behaviour of the disc white dwarf luminosity\nfunction for several assumptions about the magnitude of the measurement errors\nand for several degrees of contamination, comparing the performances of the\nmost robust luminosity function estimators under such conditions.", "We discuss the abundance of Compton-thick AGN as estimated by the most recent\npopulation synthesis models of the cosmic X-ray background. Only a small\nfraction of these elusive objects have been detected so far, in line with the\nmodel expectations. The advances expected by the broad band detectors on board\nSuzaku are briefly reviewed.", "We introduce two sets of continuum equations to describe granular flow on a\nfree surface and study their properties. The equations derived from a\nmicroscopic picture that includes jumps and a mobility threshold, account for\nripple and crater formation.", "Recently the authors used the Kadanoff-Baym non-equilibrium Green's function\nformalism to derive kinetic equation for the non-condensate atoms, in\nconjunction with a consistent generalization of the Gross-Pitaevskii equation\nfor the Bose condensate wavefunction. This work was limited to high\ntemperatures, where the excited atoms could be described by a\n  Hartree-Fock particle-like spectrum. We present the generalization of this\nrecent work to low temperatures, where the single-particle spectrum is now\ndescribed by the Bogoliubov-Popov approximation. We derive a kinetic equation\nfor the quasiparticle distribution function with collision integrals describing\nscattering between quasiparticles and the condensate atoms. From the general\nexpression for the collision integral for the scattering between quasiparticle\nexcitations, we find the quasiparticle distribution function corresponding to\nlocal equilibrium. This expression includes a quasiparticle chemical potential\nthat controls the non-diffusive equilibrium between condensate atoms and the\nquasiparticle excitations. We also derive a generalized Gross-Pitaevskii\nequation for the condensate wavefunction that includes the damping effects due\nto collisions between atoms in the condensate and the thermally excited\nquasiparticles. For a uniform Bose gas, our kinetic equation for the thermally\nexcited quasiparticles reduces to that found by Eckern as well as Kirkpatrick\nand Dorfman.", "We make a systematic analysis of the XMM-Newton X-ray spectra of intermediate\npolars (IPs) and find that, contrary to the traditional picture, most show a\nsoft blackbody component. We compare the results with those from AM Her stars\nand deduce that the blackbody emission arises from reprocessing of hard X-rays,\nrather than from the blobby accretion sometimes seen in AM Hers. Whether an IP\nshows a blackbody component appears to depend primarily on geometric factors: a\nblackbody is not seen in those that have accretion footprints that are always\nobscured by accretion curtains or are only visible when foreshortened on the\nwhite-dwarf limb. Thus we argue against previous suggestions that the blackbody\nemission characterises a separate sub-group of IPs which are more akin to AM\nHers, and develop a unified picture of the blackbody emission in these stars.", "Using continued fractions we study the ground state properties of the\nspin-1/2 Ising chain in a transverse field with periodically varying\ninteraction strengths and external fields. We consider in detail the chain\nhaving the period of modulation of interactions equals 2 and compare the\nresults obtained with those corresponding to the spin-1/2 isotropic XY chain in\na transverse field. In contrast to the behaviour of the transverse XY chain,\nthe transverse Ising chain does not exhibit a step-like magnetization vs. field\ndependence caused by the alternation of bonds, its susceptibility exhibits a\nlogarithmic singularity at the field determined by interaction strengths, and\nit is stable with respect to spin-Peierls dimerization.", "The recent accurate measurements of Berg, Moldover and Zimmerli of the\nviscoelastic effect near the critical point of xenon has shown that the scale\nfactor involved in the frequency scaling is about twice the scale factor\nobtained theoretically. We show that this discrepancy is a consequence of using\nfirst order perturbation theory. Including two loop contribution goes a long\nway towards removing the discrepancy.", "We introduce a family of correlated trial wave functions for the $N$-particle\nground state of an interacting Bose gas in a harmonic trap. For large $N$, the\ncorrelations lead to a relative energy decrease of a fraction $3/5N$, compared\nto mean field Gross-Pitaevskii theory. The kinetic energy in the weakly\nconfining direction turns out to be most sensitive to our correlations and,\nremarkably, is higher by as much as a few per cent for condensates with atom\nnumbers of a few thousand. Thus, the predicted deviations from Gross-Pitaevskii\ntheory originating from ground state correlations might be observed in momentum\ndistribution measurements of small condensates.", "We present a new, semi-phenomenologocal method to extract the condensate\nfraction n_0(T) from two sets of measured responses of ^4He with identical\nkinematis at T<T_c and T>T_c.", "Abridged: We present analysis of Spitzer Space Telescope observations of the\nthree low surface brightness (LSB) optical giant galaxies Malin 1, UGC 6614 and\nUGC 9024. Mid- and far-infrared morphology, spectral energy distributions, and\nintegrated colors are used to derive the dust mass, dust-to-gas mass ratio,\ntotal infrared luminosity, and star formation rate (SFR). The 8 micron images\nindicate that polycyclic aromatic hydrocarbon molecules are present in the\ncentral regions of all three metal-poor LSB galaxies. The diffuse optical disks\nof Malin 1 and UGC 9024 remain undetected at mid- and far-infrared wavelengths.\nThe dustiest of the three LSB galaxies, UGC 6614, has infrared morphology that\nvaries significantly with wavelength. The 8 and 24 micron emission is\nco-spatial with H\\alpha emission previously observed in the outer ring of UGC\n6614. The estimated dust-to-gas ratios, from less than 10^{-3} to 10^{-2},\nsupport previous indications that the LSB galaxies are relatively dust poor\ncompared to the HSB galaxies. The total infrared luminosities are approximately\n1/3 to 1/2 the blue band luminosities, suggesting that old stellar populations\nare the primary source of dust heating in these LSB objects. The SFR estimated\nfrom the infrared data ranges ~0.01-0.88 M_sun yr^{-1}, consistent with results\nfrom optical studies.", "First results of observations of the low mass X-ray binary Her X-1/HZ Her\nperformed by the INTEGRAL satellite in July-August 2005 are presented. A\nsignificant part of one 35 day main-on state was covered. The cyclotron line in\nthe X-ray spectrum is well observed and its position and shape, as well as its\nvariability with time and phase of the 1.24 s pulsation are explored. X-ray\npulse profiles for different energy bands are studied throughout the\nobservation. The pulse period is found to vary on short time scales revealing a\ndynamical spin-up/spin-down behavior. Results of simultaneous optical\nobservations of HZ Her are also discussed.", "It was found that approximately constant column densities of giant molecular\nclouds (Larson's low) can be explained as cloud existence condition in external\n(galactic) gravitational field. This condition can be also applied to objects\n(clumps and cores) embedded into the cloud and its gravitational field. Derived\nexistence condition do not rely on any internal dynamic of a cloud and embedded\nobjects.", "We present a 127deg x 63deg extinction map of the Anticenter of the Galaxy,\nbased on <J-H> and <H-K> colour excess maps from 2MASS. This 8001 square degree\nmap with a resolution of 4 arcminutes is provided as online material. The\ncolour excess ratio <J-H> / <H-K> is used to determine the power law index of\nthe reddening law (\\beta) for individual regions contained in the area (e.g.\nOrion, Perseus, Taurus, Auriga, Monoceros, Camelopardalis, Cassiopeia). On\naverage we find a dominant value of \\beta=1.8+-0.2 for the individual clouds,\nin agreement with the canonical value for the interstellar medium. We also show\nthat there is an internal scatter of \\beta values in these regions, and that in\nsome areas more than one dominant \\beta value is present. This indicates large\nscale variations in the dust properties. The analysis of the A_V values within\nindividual regions shows a change in the slope of the column density\ndistribution with distance. This can either be attributed to a change in the\ngoverning physical processes in molecular clouds on spatial scales of about 1pc\nor an A_V dilution with distance in our map.", "The three-dimensional $q$-state Potts model, forced into coexistence by\nfixing the density of one state, is studied for $q=2$, 3, 4, and 6. As a\nfunction of temperature and number of states, we studied the resulting\nequilibrium droplet shapes. A theoretical discussion is given of the interface\nproperties at large values of $q$. We found a roughening transition for each of\nthe numbers of states we studied, at temperatures that decrease with increasing\n$q$, but increase when measured as a fraction of the melting temperature. We\nalso found equilibrium shapes closely approaching a sphere near the melting\npoint, even though the three-dimensional Potts model with three or more states\ndoes not have a phase transition with a diverging length scale at the melting\npoint.", "We have analyzed the HI aperture synthesis image of the Large Magellanic\nCloud (LMC), using an objective and quantitative measure of topology to\nunderstand the HI distribution hosting a number of holes and clumps of various\nsizes in the medium. The HI distribution shows different topology at four\ndifferent chosen scales. At the smallest scales explored (19-29 pc), the HI\nmass is distributed in such a way that numerous clumps are embedded on top of a\nlow density background. At the larger scales from 73 to 194 pc, it shows a\ngeneric hole topology. These holes might have been formed mainly by stellar\nwinds from hot stars. At the scales from 240 to 340 pc, slightly above the disk\nscale-height of the gaseous disk, major clumps in the HI map change the\ndistribution to have a slight clump topology. These clumps include the giant\ncloud associations in the spiral arms and the thick filaments surrounding\nsuperholes. At the largest scales studied (390-485 pc), the hole topology is\npresent again. Responsible to the hole topology at this scale are a few\nsuperholes which seem mainly associated with supernova explosions in the outer\ndisk. The gaps between the bar and spiral arms have a minor effect on the\ntopology at this scale.", "The nonlinear interaction of DC current flowing in a thin metal film with an\nexternal low-frequency AC electromagnetic field is studied theoretically. The\nnonlinearity is related to the influence of the magnetic field of the DC\ncurrent and the magnetic field of the wave on the form of electron\ntrajectories. This magnetodynamic mechanism of nonlinearity is the most typical\nfor pure metals at low temperatures. We find that such interaction causes sharp\nkinks in the temporal dependence of the AC electric field of the wave on\nsurface of the sample. The phenomenon of amplification of the electromagnetic\nsignal on the metal surface is predicted. We also calculate the nonlinear\nsurface impedance and show that it turns out to be imaginary-valued and its\nmodulus decreases drastically with the increase of the wave amplitude.", "Close pre-main-sequence binary stars are expected to clear central holes in\ntheir protoplanetary disks, but the extent to which material can flow from the\ncircumbinary disk across the gap onto the individual circumstellar disks has\nbeen unclear. In binaries with eccentric orbits, periodic perturbation of the\nouter disk is predicted to induce mass flow across the gap, resulting in\naccretion that varies with the binary period. This accretion may manifest\nitself observationally as periodic changes in luminosity. Here we present a\nsearch for such periodic accretion in the pre-main-sequence spectroscopic\nbinary UZ Tau E. We present BVRI photometry spanning three years; we find that\nthe brightness of UZ Tau E is clearly periodic, with a best-fit period of 19.16\n+/- 0.04 days. This is consistent with the spectroscopic binary period of 19.13\ndays, refined here from analysis of new and existing radial velocity data. The\nbrightness of UZ Tau E shows significant random variability, but the overall\nperiodic pattern is a broad peak in enhanced brightness, spanning more than\nhalf the binary orbital period. The variability of the H-alpha line is not as\nclearly periodic, but given the sparseness of the data, some periodic component\nis not ruled out. The photometric variations are in good agreement with\npredictions from simulations of binaries with orbital parameters similar to\nthose of UZ Tau E, suggesting that periodic accretion does occur from\ncircumbinary disks, replenishing the inner disks and possibly extending the\ntimescale over which they might form planets.", "We use a modified Thomas-Fermi approximation to estimate analytically the\ncritical velocity for the formation of vortices in harmonically trapped BEC. We\ncompare this analytical estimate to numerical calculations and to recent\nexperiments on trapped alkali condensates.", "We have systematically studied superconducting instabilities in the repulsive\nHubbard model for d-wave and p-wave pairing in various 2D and 3D lattices.\nUsing fluctuation exchange approximation, we consider 3D face centered cubic\nlattice, 3D body centered cubic lattice, 3D simple cubic lattice, 2D square\nlattice and 2D triangular lattice, where either strong ferro- or\nantiferromagnetic spin fluctuation is present. We show that (i) d-wave\ninstability mediated by antiferromagnetic spin fluctuations is stronger than\np-wave instability mediated by ferromagnetic spin fluctuations both in 2D and\n3D, and (ii)d-wave instability in 2D is much stronger than that in 3D. These\namount that the \"best\" situation is the antiferromagnetic-fluctuation mediated\nin 2D as far as the single-band Hubbard model on ordinary lattices are\nconcerned.", "Ultra-High-Energy (UHE) ($E>100 $TeV) Extensive Air Showers (EASs) have been\nmonitored for a period of five years (1997-2003), using a small array of\nscintillation detectors in Tehran, Iran. The data have been analyzed to take in\nto account of the dependence of source counts on zenith angle. Because of\nvarying thickness of the overlaying atmosphere, the shower count rate is\nextremely dependent on zenith angle. During a calendar year different sources\ncome in the field of view of the array at varying zenith angles and have\ndifferent effective observation time equivalent to zenith in a day. High energy\ngamma-ray sources from the EGRET third catalogue where observed and the data\nwere analyzed using an excess method. Upper limits were obtained for 10 EGRET\nsources. Then we investigated the EAS event rates for these 10 sources and\nobtained a flux for each of them using parameters of our experiment results and\nsimulations. Finally we investigated the gamma-ray spectrum in the UHE range\nusing these fluxes with reported fluxes of the EGRET sources.", "Adsorption of benzene on the Si(100) surface is studied from first\nprinciples. We find that the most stable configuration is a\ntetra-$\\sigma$-bonded structure characterized by one C-C double bond and four\nC-Si bonds. A similar structure, obtained by rotating the benzene molecule by\n90 degrees, lies slightly higher in energy. However, rather narrow wells on the\npotential energy surface characterize these adsorption configurations. A\nbenzene molecule impinging on the Si surface is most likely to be adsorbed in\none of three different di-$\\sigma$-bonded, metastable structures, characterized\nby two C-Si bonds, and eventually converts into the lowest-energy\nconfigurations. These results are consistent with recent experiments.", "We calculate the second topological moment < m^2 > of entanglement of two\nclosed polymers $P_1$ and $P_2$ in a solution. The result holds approximately\nfor a closed polymer linked to many others, which may be considered as a single\nvery long effective polymer.", "We carry out the direct minimization of the energy functional proposed by\nMauri, Galli and Car to derive the correct self-consistent ground state with\nfractional occupation numbers for a system degenerating at the Fermi level. As\na consequence, this approach enables us to determine the electronic structure\nof metallic systems to a high degree of accuracy without the aid of level\nbroadening of the Fermi-distribution function. The efficiency of the method is\nillustrated by calculating the ground-state energy of C$_2$ and Si$_2$\nmolecules and the W(110) surface to which a tungsten adatom is adsorbed.", "We present the first result of the Ital-FLAMES survey of red giant branch\n(RGB) stars in omega Cen. Radial velocities with a precision of ~0.5 km/s are\npresented for 650 members of omega Cen observed with FLAMES-Giraffe at the Very\nLarge Telescope. We found that stars belonging to the metal -poor (RGB-MP),\nmetal-intemediate (RGB-MInt) and metal-rich (RGB-a) sub -populations of Omega\nCen are all compatible with having the same rotational pattern. Our results\nappear to contradict past findings by Norris et al., who could not detect any\nrotational signature for metal -rich stars. The slightly higher precision of\nthe present measurements and the much larger sample size, especially for the\nmetal-richer stars, appear as the most likely explanation for this discrepancy.\nThe result presented here weakens the body of evidence in favour of a merger\nevent in the past history of omega Cen.", "Methanol maser emission has proven to be an excellent signpost of regions\nundergoing massive star formation (MSF). To investigate their role as an\nevolutionary tracer, we have recently completed a large observing program with\nthe ATCA to derive the dynamical and physical properties of molecular/ionised\ngas towards a sample of MSF regions traced by 6.7 GHz methanol maser emission.\nWe find that the molecular gas in many of these regions breaks up into multiple\nsub-clumps which we separate into groups based on their association\nwith/without methanol maser and cm continuum emission. The temperature and\ndynamic state of the molecular gas is markedly different between the groups.\nBased on these differences, we attempt to assess the evolutionary state of the\ncores in the groups and thus investigate the role of class II methanol masers\nas a tracer of MSF.", "The presence of dust at high redshift requires efficient condensation of\ngrains in SN ejecta, in accordance with current theoretical models. Yet,\nobservations of the few well studied SNe and SN remnants imply condensation\nefficiencies which are about two orders of magnitude smaller. Motivated by this\ntension, we have (i) revisited the model of Todini & Ferrara (2001) for dust\nformation in the ejecta of core collapse SNe and (ii) followed, for the first\ntime, the evolution of newly condensed grains from the time of formation to\ntheir survival - through the passage of the reverse shock - in the SN remnant.\nWe find that 0.1 - 0.6 M_sun of dust form in the ejecta of 12 - 40 M_sun\nstellar progenitors. Depending on the density of the surrounding ISM, between\n2-20% of the initial dust mass survives the passage of the reverse shock, on\ntime-scales of about 4-8 x 10^4 yr from the stellar explosion. Sputtering by\nthe hot gas induces a shift of the dust size distribution towards smaller\ngrains. The resulting dust extinction curve shows a good agreement with that\nderived by observations of a reddened QSO at z =6.2. Stochastic heating of\nsmall grains leads to a wide distribution of dust temperatures. This supports\nthe idea that large amounts (~ 0.1 M_sun) of cold dust (T ~ 40K) can be present\nin SN remnants, without being in conflict with the observed IR emission.", "We study numerically the time evolution of two-dimensional (2D) domain\npatterns in proper tetragonal-orthorhombic (T-O) ferroelastics. Our results,\nfound by solving equations of motion derived from classical elasticity theory,\ndisagree with those found by other methods. We study first the growth of the 2D\nnucleus resulting from homogeneous nucleation events. The later shape of the\nnucleus is largely independent of how it was nucleated. In soft systems, the\nnucleus forms a flower-like pattern. In stiff systems, which seem to be more\nrealistic, it forms an X shape with twinned arms in the 110 and \\110\ndirections. Second, we study the relaxation that follows completion of the\nphase transition; at these times, the T phase has disappeared and both O\nvariants are present, segregated into domains separated by domain walls. We\nobserve a variety of coarsening mechanisms, most of them counterintuitive.", "We report precision Doppler measurements of three intermediate-mass subgiants\nfrom Lick and Keck Observatories. All three stars show variability in their\nradial velocities consistent with planet-mass companions in Keplerian orbits.\nWe find a planet with a minimum mass of 2.5 Mjup in a 351.5 day orbit around HD\n192699, a planet with a minimum mass of 2.0 Mjup in a 341.1 day orbit around HD\n210702, and a planet with a minimum mass of 0.61 Mjup in a 297.3 day orbit\naround HD 175541. Stellar mass estimates from evolutionary models indicate that\nall of these stars were formerly A-type dwarfs with masses ranging from 1.65 to\n1.85 Msun. These three long-period planets would not have been detectable\nduring their stars' main-sequence phases due to the large rotational velocities\nand stellar jitter exhibited by early-type dwarfs. There are now 9 \"retired\"\n(evolved) A-type stars (Mstar > 1.6 Msun) with known planets. All 9 planets\norbit at distances a \\geq 0.78 AU, which is significantly different than the\nsemimajor axis distribution of planets around lower-mass stars. We examine the\npossibility that the observed lack of close-in planets is due to engulfment by\ntheir expanding host stars, but we find that this explanation is inadequate\ngiven the relatively small stellar radii of K giants (Rstar < 32 Rsun = 0.15\nAU) and subgiants (Rstar < 7 Rsun = 0.03 AU). Instead, we conclude that planets\naround intermediate-mass stars reside preferentially beyond ~0.8 AU, which may\nbe a reflection of different formation and migration histories of planets\naround A-type stars.", "Single index financial market models cannot account for the empirically\nobserved complex interactions between shares in a market. We describe a\nmulti-share financial market model and compare characteristics of the\nvolatility, that is the standard deviation of the price fluctuations, with\nempirical characteristics. In particular we find its probability distribution\nis similar to a log normal distribution but with a long power-law tail for the\nlarge fluctuations, and that the time development shows superdiffusion. Both\nthese results are in good quantitative agreement with observations.", "We present general relativistic correction terms appearing in Newton's\ngravity to the second-order perturbations of cosmological fluids. In our\nprevious work we have shown that to the second-order perturbations, the density\nand velocity perturbation equations of general relativistic zero-pressure,\nirrotational, single-component fluid in a flat background coincide exactly with\nthe ones known in Newton's theory. Here, we present the general relativistic\nsecond-order correction terms arising due to (i) pressure, (ii)\nmulti-component, (iii) background curvature, and (iv) rotation. In case of\nmulti-component zero-pressure, irrotational fluids under the flat background,\nwe effectively do not have relativistic correction terms, thus the relativistic\nresult again coincides with the Newtonian ones. In the other three cases we\ngenerally have pure general relativistic correction terms. In case of pressure,\nthe relativistic corrections appear even in the level of background and linear\nperturbation equations. In the presence of background curvature, or rotation,\npure relativistic correction terms directly appear in the Newtonian equations\nof motion of density and velocity perturbations to the second order. In the\nsmall-scale limit (far inside the horizon), relativistic equations including\nthe rotation coincide with the ones in Newton's gravity.", "In a series of recent papers, a new formalism has been developed that\nexplains the inner structure of dark matter halos as collisionless,\ndissipationless systems assembled through mergers and accretion at the typical\ncosmological rate. Nearby ellipticals are also collisionless, dissipationless\nsystems assembling their mass through mergers, but contrarily to the former\nstructures they do not continuously accrete external matter because they are\nshielded by their host halos. Here we explore the idea that the infall of their\nown matter ejected within the halo on the occasion of a violent merger can play\na role similar to external accretion in halos. The predicted stellar mass\ndensity profile fits the observed one, and the empirical total mass density\nprofile is also recovered.", "GEMS and GOODS fields were examined to z~1.4 for galaxy interactions and\nmergers. The basic morphologies are familiar: antennae with long tidal tails,\ntidal dwarfs, and merged cores; M51-type galaxies with disk spirals and tidal\narm companions; early-type galaxies with diffuse plumes; equal-mass\ngrazing-collisions; and thick J-shaped tails beaded with star formation and\ndouble cores. One type is not common locally and is apparently a loose\nassemblage of smaller galaxies. Photometric measurements were made of the tails\nand clumps, and physical sizes were determined assuming photometric redshifts.\nAntennae tails are a factor of ~3 smaller in GEMS and GOODS systems compared to\nlocal antennae; their disks are a factor of ~2 smaller than locally. Collisions\namong early type galaxies generally show no fine structure in their tails,\nindicating that stellar debris is usually not unstable. One exception has a\n5x10**9 Msun smooth red clump that could be a pure stellar condensation. Most\ntidal dwarfs are blue and probably form by gravitational instabilities in the\ngas. One tidal dwarf looks like it existed previously and was incorporated into\nthe arm tip by tidal forces. The star-forming regions in tidal arms are 10 to\n1000 times more massive than star complexes in local galaxies, although their\nseparations are about the same. If they all form by gravitational\ninstabilities, then the gaseous velocity dispersions in interacting galaxies\nhave to be larger than in local galaxies by a factor of ~5 or more; the gas\ncolumn densities have to be larger by the square of this factor.", "The large quantity and high quality of modern radio and infrared line\nobservations require efficient modeling techniques to infer physical and\nchemical parameters such as temperature, density, and molecular abundances. We\npresent a computer program to calculate the intensities of atomic and molecular\nlines produced in a uniform medium, based on statistical equilibrium\ncalculations involving collisional and radiative processes and including\nradiation from background sources. Optical depth effects are treated with an\nescape probability method. The program is available on the World Wide Web at\nhttp://www.sron.rug.nl/~vdtak/radex/index.shtml . The program makes use of\nmolecular data files maintained in the Leiden Atomic and Molecular Database\n(LAMDA), which will continue to be improved and expanded. The performance of\nthe program is compared with more approximate and with more sophisticated\nmethods. An Appendix provides diagnostic plots to estimate physical parameters\nfrom line intensity ratios of commonly observed molecules. This program should\nform an important tool in analyzing observations from current and future radio\nand infrared telescopes.", "Pulay's Residual Metric Minimization (RMM) method is one of the standard\ntechniques for achieving self consistency in ab initio electronic structure\ncalculations. We describe a reformulation of Pulay's RMM which guarantees\nreduction of the residual at each step. The new version avoids the use of\nempirical mixing parameters, and is expected to be more robust than the\noriginal version. We present practical tests of the new method implemented in a\nstandard code based on density-functional theory (DFT), pseudopotentials, and\nplane-wave basis sets. The tests show improved speed in achieving self\nconsistency for a variety of condensed-matter systems.", "Despite progress in the theoretical knowledge of open cluster remnants and\nthe growing search for observational identifications in recent years, open\nquestions still remain. The methods used to analyze open cluster remnants and\ncriteria to define them as physical systems are not homogeneous. In this work\nwe present a systematic method for studying these objects that provides a view\nof their properties and allows their characterization. Eighteen remnant\ncandidates are analyzed by means of photometric and proper motion data. These\ndata provide information on objects and their fields. We establish criteria for\ncharacterizing open cluster remnants, taking observational uncertainties into\naccount. 2MASS J and H photometry is employed (i) to study structural\nproperties of the objects by means of radial stellar density profiles, (ii) to\ntest for any similarity between objects and fields with a statistical\ncomparison method applied to the distributions of stars in the CMDs, and (iii)\nto obtain ages, reddening values, and distances from the CMD, taking an index\nof isochrone fit into account. The UCAC2 proper motions allowed an objective\ncomparison between objects and large solid angle offset fields. The objective\nanalysis based on the present methods indicates 13 open-cluster remnants in the\nsample. Evidence of the presence of binary stars is found, as expected for\ndynamically evolved systems. Finally, we infer possible evolutionary stages\namong remnants from the structure, proper motion, and CMD distributions. The\nlow stellar statistics for individual objects is overcome by means of the\nconstruction of composite proper motion and CMD diagrams. The distributions of\nremnants in the composite diagrams resemble the single-star and unresolved\nbinary star distributions of open clusters.", "We have formulated a kinetic theory for a condensed atomic gas in a trap,\ni.e., a generalized Gross-Pitaevskii equation, as well as a quantum-Boltzmann\nequation for the normal and anomalous fluctuations [R. Walser et al., Phys.\nRev. A, 59, 3878 (1999)]. In this article, the theory is applied to the case of\nan isotropic configuration and we present numerical and analytical results for\nthe reversible real-time propagation, as well as irreversible evolution towards\nequilibrium.", "We report single crystal growth and magnetic susceptibility and neutron\ndiffraction studies of the S=1/2 quasi-1D antiferromagnet CaCu2O3. The\nstructure of this material is similar to that of the prototype two-leg\nspin-ladder compound SrCu2O3. However, the Cu-O-Cu bond angle in the ladder\nrungs in CaCu2O3 is equal to 123 deg, and therefore the magnetic interaction\nalong the rungs is expected to be much weaker in this material. At high\ntemperatures, the magnetic susceptibility of CaCu2O3 can be decomposed into a\ncontribution from 1D antiferromagnetic chains of finite-size chain segments\ntogether with a weak Curie contribution. The intrachain magnetic exchange\nconstant, determined from the magnetic susceptibility measurements, is 2000 K.\nCaCu2O3 undergoes a Neel transition at T_N=25 K with ordering wavevector of\n(0.429(5), 0.5, 0.5). The magnetic structure is incommensurate in the direction\nof the frustrated interchain interaction. Weak commensurate (0.5, 0.5, 0.5)\nmagnetic peaks are also observed below T_N. Application of a magnetic field\ninduces a metamagnetic transition at which the incommensurability of the\nmagnetic structure is substantially reduced. The material possesses only\nshort-range magnetic order above the transition field.", "We performed interferometric observations of a high-mass protostellar\ncandidate IRAS 18566+0408 in the \\nh3 (J,K)=(1,1), (2,2) and (3,3) inversion\ntransitions, the SiO J=2-1 and HCN J=1-0 lines, and the 43 and 87 GHz continuum\nemission using the VLA and OVRO. The 87 GHz continuum emission reveals two\ncontinuum peaks MM-1 and MM-2 along a molecular ridge. The dominant peak MM-1\ncoincides with a compact emission feature at 43 GHz, and arises mostly from the\ndust emission. For dust emissivity index $\\beta$ of 1.3, the masses in the dust\npeaks amount to 70 \\msun for MM-1, and 27 \\msun for MM-2. Assuming internal\nheating, the central luminosities of MM-1 and MM-2 are $6 \\times 10^4$ and $8\n\\times 10^3$ \\lsun, respectively.\n  The SiO emission reveals a well collimated outflow emanating from MM-1. The\njet-like outflow is also detected in \\nh3 at velocities similar to the SiO\nemission. The outflow, with a mass of 27 \\msun, causes significant heating in\nthe gas to temperatures of 70 K, much higher than the temperature of $\\lsim 15$\nK in the extended core. Compact ($< 3''$) and narrow line ($<1.5$ \\kms-1) \\nh3\n(3,3) emission features are found associated with the outflow. They likely\narise from weak population inversion in \\nh3 similar to the maser emission.\n  Toward MM-1, there is a compact \\nh3 structure with a linewidth that\nincreases from 5.5 \\kms-1 FHWM measured at 3$''$ resolution to 8.7 \\kms-1\\\nmeasured at 1$''$ resolution. This linewidth is much larger than the FWHM of\n$<$ 2 \\kms-1 in the entire core, and does not appear to originate from the\noutflow. This large linewidth may arise from rotation/infall, or relative\nmotions of unresolved protostellar cores.", "We determine approximate formula for the ground state energy of anyons in 2D\nparabolic well which is valid for the arbitrary anyonic factor \\nu and number\nof particles N in the system. We assume that centre of mass motion energy is\nnot excluded from the energy of the system. Formula for ground state energy\ncalculated by variational principle contains logarithmic divergence at small\ndistances between two anyons which is regularized by cut-off parameter. By\nequating this variational formula to the analogous formula of Wu near bosonic\nlimit (\\nu ~ 0)we determine the value of the cut-off and thus derive the\napproximate formula for the ground state energy for the any \\nu and N. We\nchecked this formula at \\nu=1, when anyons become fermions, for the systems\ncontaining two to thirty particles. We find that our approximate formula has an\naccuracy within 6%. It turns out, at the big number N limit the ground state\nenergy has square root dependence on factor \\nu.", "We consider that the pre-inflation era is radiation-dominated, transiting\nsmoothly to the inflationary era. We work out in detail the dynamics of\ninflaton fluctuations across the phase transition and the proper choices of\ninitial vacuum states. It is found that this phase transition can suppress\nlong-wavelength quantum fluctuations of inflaton. This may attribute to the\nlarge-scale CMB anisotropy a lower power than predicted in the standard\n$\\Lambda$CDM model. In constraining this transitional effect by WMAP anisotropy\ndata, we use the WMAP best-fit scale-invariant $\\Lambda$CDM model with the\ndensity power spectrum replaced by the one found in this work. We find that the\ntransition occurs at least about 10 e-folds before the comoving scales\ncomparable to our present horizon size cross the Hubble radius during\ninflation.", "Disk instability is an attractive yet controversial means for the rapid\nformation of giant planets in our solar system and elsewhere. Recent concerns\nregarding the first adiabatic exponent of molecular hydrogen gas are addressed\nand shown not to lead to spurious clump formation in the author's disk\ninstability models. A number of disk instability models have been calculated in\norder to further test the robustness of the mechanism, exploring the effects of\nchanging the pressure equation of state, the vertical temperature profile, and\nother parameters affecting the temperature distribution. Possible reasons for\ndifferences in results obtained by other workers are discussed. Disk\ninstability remains as a plausible formation mechanism for giant planets.", "We investigate the acceleration and simultaneous radiative losses of\nelectrons in the vicinity of relativistic shocks. Particles undergo pitch angle\ndiffusion, gaining energy as they cross the shock by the Fermi mechanism and\nalso emitting synchrotron radiation in the ambient magnetic field. A\nsemi-analytic approach is developed which allows us to consider the behaviour\nof the shape of the spectral cut-off and the variation of that cut-off with the\nparticle pitch angle. The implications for the synchrotron emission of\nrelativistic jets, such as those in gamma ray burst sources and blazars, are\ndiscussed.", "Previous observations with the Rossi X-ray Timing Explorer (RXTE) have\nsuggested that the power spectral density (PSD) of NGC 3783 flattens to a slope\nnear zero at low frequencies, in a similar manner to that of Galactic black\nhole X-ray binary systems (GBHs) in the `hard' state. The low radio flux\nemitted by this object, however, is inconsistent with a hard state\ninterpretation. The accretion rate of NGC 3783 (~7% of the Eddington rate) is\nsimilar to that of other AGN with `soft' state PSDs and higher than that at\nwhich the GBH Cyg X-1, with which AGN are often compared, changes between\n`hard' and `soft' states (~2% of the Eddington rate). If NGC 3783 really does\nhave a `hard' state PSD, it would be quite unusual and would indicate that AGN\nand GBHs are not quite as similar as we currently believe. Here we present an\nimproved X-ray PSD of NGC 3783, spanning from ~10^{-8} to ~10^{-3} Hz, based on\nconsiderably extended (5.5 years) RXTE observations combined with two orbits of\ncontinuous observation by XMM-Newton. We show that this PSD is, in fact, well\nfitted by a `soft' state model which has only one break, at high frequencies.\nAlthough a `hard' state model can also fit the data, the improvement in fit by\nadding a second break at low frequency is not significant. Thus NGC 3783 is not\nunusual. These results leave Arakelian 564 as the only AGN which shows a second\nbreak at low frequencies, although in that case the very high accretion rate\nimplies a `very high', rather than `hard' state PSD. The break frequency found\nin NGC 3783 is consistent with the expectation based on comparisons with other\nAGN and GBHs, given its black hole mass and accretion rate.", "We have searched for the SiO J=1--0 v= 1 and 2 maser lines at ~ 43 GHz in 277\n2MASS/MSX/IRAS sources off the Galactic plane (|b|> 3 deg), which resulted in\n119 (112 new) detections. Among the new detections, are two very faint objects\nwith MSX 12 micron flux densities below 2 Jy. These are likely to be O-rich\nAGB-stars associated with dwarf-galaxy tidal tails. The sample also includes\nmedium bright MSX objects at moderately high Galactic latitudes (3 deg<|b|<5\ndeg) and in the IRAS gap at higher latitudes. A signature of a warp of the\ninner Galactic disk is found for a disk subsample. This warp appears relatively\nstrongly in the area of 0<l<45 deg and 3<|b|<5 deg. We also found a group of\nstars that does not follow to the Galactic rotation. This feature appears in\nthe Galactic disk at l~ 27 deg, and extends more than 15 deg in Galactic\nlatitude, like a stream of tidal debris from a dwarf galaxy.", "The understanding of the instrumental response of the GLAST Burst Monitor BGO\ndetectors at energies above the energy range which is accessible by common\nlaboratory radiation sources (< 4.43 MeV), is important, especially for the\nlater cross-calibration with the LAT response in the overlap region between ~\n20 MeV to 30 MeV. In November 2006 the high-energy calibration of the GBM-BGO\nspare detector was performed at the small Van-de-Graaff accelerator at SLAC.\nHigh-energy gamma-rays from excited 8Be* (14.6 MeV and 17.5 MeV) and 16O* (6.1\nMeV) were generated through (p,gamma)-reactions by irradiating a LiF-target.\nFor the calibration at lower energies radioactive sources were used. The\nresults, including spectra, the energy/channel-relation and the dependence of\nenergy resolution are presented.", "We present a study of the connection between star-forming galaxies, AGN host\ngalaxies, and normal early-type galaxies in the Sloan Digital Sky Survey\n(SDSS). Using the SDSS DR5 and DR4plus data, we select our early-type galaxy\nsample in the color versus color-gradient space, and we classify the spectral\ntypes of the selected early-type galaxies into normal, star-forming, Seyfert,\nand LINER classes, using several spectral line flux ratios. We investigate the\nslope in the fundamental space for each class of early-type galaxies and find\nthat there are obvious differences in the slopes of the fundamental planes\n(FPs) among the different classes of early-type galaxies, in the sense that the\nslopes for Seyferts and star-forming galaxies are flatter than those for normal\ngalaxies and LINERs. This may be the first identification of the systematic\nvariation of the FP slope among the subclasses of early-type galaxies. The\ndifference in the FP slope might be caused by the difference in the degree of\nnonhomology among different classes or by the difference of gas contents in\ntheir merging progenitors. One possible scenario is that the AGN host galaxies\nand star-forming galaxies are formed by gas-rich merging and that they may\nevolve into normal early-type galaxies after finishing their star formation or\nAGN activities.", "The absolute calibration and characterization of the Multiband Imaging\nPhotometer for Spitzer (MIPS) 70 micron coarse- and fine-scale imaging modes\nare presented based on over 2.5 years of observations. Accurate photometry\n(especially for faint sources) requires two simple processing steps beyond the\nstandard data reduction to remove long-term detector transients. Point spread\nfunction (PSF) fitting photometry is found to give more accurate flux densities\nthan aperture photometry. Based on the PSF fitting photometry, the calibration\nfactor shows no strong trend with flux density, background, spectral type,\nexposure time, or time since anneals. The coarse-scale calibration sample\nincludes observations of stars with flux densities from 22 mJy to 17 Jy, on\nbackgrounds from 4 to 26 MJy sr^-1, and with spectral types from B to M. The\ncoarse-scale calibration is 702 +/- 35 MJy sr^-1 MIPS70^-1 (5% uncertainty) and\nis based on measurements of 66 stars. The instrumental units of the MIPS 70\nmicron coarse- and fine-scale imaging modes are called MIPS70 and MIPS70F,\nrespectively. The photometric repeatability is calculated to be 4.5% from two\nstars measured during every MIPS campaign and includes variations on all time\nscales probed. The preliminary fine-scale calibration factor is 2894 +/- 294\nMJy sr^-1 MIPS70F^-1 (10% uncertainty) based on 10 stars. The uncertainty in\nthe coarse- and fine-scale calibration factors are dominated by the 4.5%\nphotometric repeatability and the small sample size, respectively. The 5-sigma,\n500 s sensitivity of the coarse-scale observations is 6-8 mJy. This work shows\nthat the MIPS 70 micron array produces accurate, well calibrated photometry and\nvalidates the MIPS 70 micron operating strategy, especially the use of frequent\nstimulator flashes to track the changing responsivities of the Ge:Ga detectors.", "We generalize recent work on parametric resonances for nonlinear\nSchr{\\\"o}dinger (NLS) type equations to the case of three dimensional\nBose-Einstein condensates at zero temperatures. We show the possibility of such\nresonances in the three-dimensional case, using a moment method and numerical\nsimulations.", "In a recent paper (A.E. Glazounov and A.K. Tagantsev, Phys.Rev. Lett. 85,\n2192 (2000)) it has been proposed a phenomenological model of the dynamic\nnon-linear response in relaxor ferroelectrics based on the averaging of the\nLandau-Khalatnikov equation over the distribution of the relaxation times. The\npurpose of the present comment is to clarify the physical assumptions involved\nin the Glazounov-Tagantsev approach and show that models based on the\nLandau-Khalatnikov equation can not describe properly the dynamic response in\nrelaxor ferroelectrics.", "Photoelectric data on the Johnson-Kron-Cousins UBVRI broadband photometric\nsystem are provided for a set of stars which have been used as\nspectrophotometric standard stars at the Hubble Space Telescope.", "The matrix elements of the deformation potential of C$_{70}$ are calculated\nby means of a simple, yet accurate solution of the electron-phonon coupling\nproblem in fullerenes, based on a parametrization of the ground state\nelectronic density of the system in terms of $sp^{2+x}$ hybridized orbitals.\nThe value of the calculated dimensionless total electron-phonon coupling\nconstant is $\\lambda\\approx0.1$, an order of magnitude smaller than in\nC$_{60}$, consistent with the lack of a superconducting phase transition in\nC$_{70}$A$_3$ fullerite, and in overall agreement with measurements of the\nbroadening of Raman peaks in C$_{70}$K$_4$. We also calculate the photoemission\ncross section of C$_{70}^-$, which is found to display less structure than that\nassociated with C$_{60}^-$, in overall agreement with the experimental\nfindings.", "A recent proposal by Maris[1], that single electron bubbles in helium might\nfission into separate, particle-like entities, does not properly take into\naccount the failure of the adiabatic approximation when, due to tunneling,\nthere is a long electronic time scale. The point along the fission pathway of a\nphotoexcited p-state bubble, where the adiabatic approximation first breaks\ndown, occurs well before the bubble waist has pinched down forming two\ncavities. In the connected two-lobed geometry, the p- and s-states are strongly\nmixed by an antisymmetric vibrational mode, and the excitation decays by the\nmechanism where one lobe collapses while the other expands into the spherical\ns-state geometry. The extreme pressure jump in a photoexcited bubble leads to\nshock formation that may halt the elongation even before adiabaticity is\ncompromised. In this case, the photoexcited bubble decays radiatively from the\nrelaxed p-state geometry.\n  [1] H.J. Maris, On the fission of elementary particles and the evidence for\nfractional electrons in liquid helium, J. Low Temp. Phys. 120, 173 (2000)", "We present the results of detailed spectroscopic abundance analyses for 18\nelements in 31 nearby stars with planets. The resulting abundances are combined\nwith other similar studies of nearby stars with planets and compared to a\nsample of nearby stars without detected planets. We find some evidence for\nabundance differences between these two samples for Al, Si and Ti. Some of our\nresults are in conflict with a recent study of stars with planets in the SPOCS\ndatabase. We encourage continued study of the abundance patterns of stars with\nplanets to resolve these discrepancies.", "We calculate the universal pressure constants of a stack of N membranes\nbetween walls by strong-coupling theory. The results are in very good agreement\nwith values from Monte-Carlo simulations.", "We numerically investigate a bosonic representation for hole pairs on a\ntwo-leg t-J ladder where hard core bosons on a chain represent the hole pairs\non the ladder. The interaction between hole pairs is obtained by fitting the\ndensity profile obtained with the effective model to the one obtained with the\n\\tj model, taking into account the inner structure of the hole pair given by\nthe hole-hole correlation function. For these interactions we calculate the\nLuttinger liquid parameter, which takes the universal value $K_{\\rho}=1$ as\nhalf filling is approached, for values of the rung exchange $J'$ between strong\ncoupling and the isotropic case. The long distance behavior of the hole-hole\ncorrelation function is also investigated. Starting from large $J'$, the\ncorrelation length first increases as expected, but diminishes significantly as\n$J'$ is reduced and bound holes sit mainly on adjacent rungs. As the isotropic\ncase is approached, the correlation length increases again. This effect is\nrelated to the different kind of bonds in the region between the two holes of a\nhole pair when they move apart.", "The subject of micro-variability among Mira stars has received increased\nattention since DeLaverny et al. (1998) reported short-term brightness\nvariations in 15 percent of the 250 Mira or Long Period Variable stars surveyed\nusing the broadband 340 to 890 nm Hp filter on the HIPPARCOS satellite. The\nabrupt variations reported ranged 0.2 to 1.1 magnitudes, on time-scales between\n2 to 100 hours, with a preponderance found nearer Mira minimum light phases.\nHowever, the HIPPARCOS sampling frequency was extremely sparse and required\nconfirmation because of potentially important atmospheric dynamics and\ndust-formation physics that could be revealed. We report on Mira light curve\nsub-structure based on new CCD V and R band data, augmenting the known light\ncurves of Hipparcos-selected long period variables [LPVs], and interpret same\nin terms of [1] interior structure, [2] atmospheric structure change, and/or\n[3] formation of circumstellar [CS] structure. We propose that the alleged\nmicro-variability among Miras is largely undersampled, transient overtone\npulsation structure in the light curves.", "Adsorption of acetylene on Si(100) is studied from first principles. We find\nthat, among a number of possible adsorption configurations, the lowest-energy\nstructure is a ``bridge'' configuration, where the C$_2$H$_2$ molecule is\nbonded to two Si atoms. Instead, ``pedestal'' configurations, recently proposed\nas the lowest-energy structures, are found to be much higher in energy and,\ntherefore, can represent only metastable adsorption sites. We have calculated\nthe surface formation energies for two different saturation coverages, namely\n0.5 and 1 monolayer, both observed in experiments. We find that although, in\ngeneral, the full monolayer coverage is favored, a narrow range of temperatures\nexists in which the 0.5 monolayer coverage is the most stable one, where the\nacetylene molecules are adsorbed in a $2\\times 2$ structure. This result\ndisagrees with the conclusions of a recent study and represents a possible\nexplanation of apparently controversial experimental findings. The crucial role\nplayed by the use of a gradient-corrected density functional is discussed.\nFinally, we study thermal decomposition of acetylene adsorbed on Si(100) by\nmeans of finite-temperature Molecular Dynamics, and we observe an unexpected\nbehavior of dehydrogenated acetylene molecules.", "We analyze the multi-time correlations of a laser-induced Bose-Einstein\ncondensate. We use quantum stochastic methods to obtain under certain\ncircumstances a Fokker-Planck equation which describes the phase-difussion\nprocess, and obtain an analytical expression of the two-time correlations. We\nperform also quantum Monte Carlo numerical simulations of the correlations,\nwhich are in good agreement with the predicted analytical results.", "We calculate the structural, electronic, and magnetic properties of MnO from\nfirst principles, using the full-potential linearized augmented planewave\nmethod, with both local-density and generalized-gradient approximations to\nexchange and correlation. We find the ground state to be of rhombohedrally\ndistorted B1 structure with compression along the [111] direction,\nantiferromagnetic with type-II ordering, and insulating, consistent with\nexperiment. We show that the distortion can be understood in terms of a\nHeisenberg model with distance dependent nearest-neighbor and\nnext-nearest-neighbor couplings determined from first principles. Finally, we\nshow that magnetic ordering can induce significant charge anisotropy, and give\npredictions for electric field gradients in the ground-state rhombohedrally\ndistorted structure.", "A number of giant HII regions are associated with soft diffuse X-ray\nemission. Among these, the Carina nebula possesses the brightest soft diffuse\nemission. The required plasma temperature and thermal energy can be produced by\ncollisions or termination of fast winds from main-sequence or embedded young O\nstars, but the extended emission is often observed from regions apart from\nmassive stellar clusters. The origin of the X-ray emission is unknown.\n  The XIS CCD camera onboard Suzaku has the best spectral resolution for\nextended soft sources so far, and is therefore capable of measuring key\nemission lines in the soft band. Suzaku observed the core and the eastern side\nof the Carina nebula (Car-D1) in 2005 Aug and 2006 June, respectively. Spectra\nof the south part of the core and Car-D1 similarly showed strong L-shell lines\nof iron ions and K-shell lines of silicon ions, while in the north of the core\nthese lines were much weaker. Fitting the spectra with an absorbed thin-thermal\nplasma model showed kT~0.2, 0.6 keV and NH~1-2e21 cm-2 with a factor of 2-3\nabundance variation in oxygen, magnesium, silicon and iron. The plasma might\noriginate from an old supernova, or a super shell of multiple supernovae.", "The derivation of a Moving Boundary Approximation or of the response of a\ncoherent structure like a front, vortex or pulse to external forces and noise,\nis generally valid under two conditions: the existence of a separation of time\nscales of the dynamics on the inner and outer scale and the existence and\nconvergence of solvability type integrals. We point out that these conditions\nare not satisfied for pulled fronts propagating into an unstable state: their\nrelaxation on the inner scale is power law like and in conjunction with this,\nsolvability integrals diverge. The physical origin of this is traced to the\nfact that the important dynamics of pulled fronts occurs in the leading edge of\nthe front rather than in the nonlinear internal front region itself. As recent\nwork on the relaxation and stochastic behavior of pulled fronts suggests, when\nsuch fronts are coupled to other fields or to noise, the dynamical behavior is\noften qualitatively different from the standard case in which fronts between\ntwo (meta)stable states or pushed fronts propagating into an unstable state are\nconsidered.", "The statistical physics approach to the number partioning problem, a\nclassical NP-hard problem, is both simple and rewarding. Very basic notions and\nmethods from statistical mechanics are enough to obtain analytical results for\nthe phase boundary that separates the ``easy-to-solve'' from the\n``hard-to-solve'' phase of the NPP as well as for the probability distributions\nof the optimal and sub-optimal solutions. In addition, it can be shown that\nsolving a number partioning problem of size $N$ to some extent corresponds to\nlocating the minimum in an unsorted list of $\\bigo{2^N}$ numbers. Considering\nthis correspondence it is not surprising that known heuristics for the\npartitioning problem are not significantly better than simple random search.", "Molecular dynamics simulations of nanometer-sized lead clusters have been\nperformed using the Lim, Ong and Ercolessi glue potential (Surf. Sci. {\\bf\n269/270}, 1109 (1992)). The binding energies of clusters forming crystalline\n(fcc), decahedron and icosahedron structures are compared, showing that fcc\ncuboctahedra are the most energetically favoured of these polyhedral model\nstructures. However, simulations of the freezing of liquid droplets produced a\ncharacteristic form of ``shaved'' icosahedron, in which atoms are absent at the\nedges and apexes of the polyhedron. This arrangement is energetically favoured\nfor 600-4000 atom clusters. Larger clusters favour crystalline structures.\nIndeed, simulated freezing of a 6525-atom liquid droplet produced an imperfect\nfcc Wulff particle, containing a number of parallel stacking faults. The\neffects of temperature on the preferred structure of crystalline clusters below\nthe melting point have been considered. The implications of these results for\nthe interpretation of experimental data is discussed.", "The Heisenberg antiferromagnet on a compressible triangular lattice in the\nspin- wave approximation is considered. It is shown that the interaction\nbetween quantum fluctuations and elastic degrees of freedom stabilizes the low\nsymmetric L-phase with a collinear Neel magnetic ordering. Multi-stability in\nthe dependence of the on-site magnetization on an unaxial pressure is found.", "The scaling behavior of linear polymers in disordered media modelled by\nself-avoiding random walks (SAWs) on the backbone of two- and three-dimensional\npercolation clusters at their critical concentrations p_c is studied. All\npossible SAW configurations of N steps on a single backbone configuration are\nenumerated exactly. We find that the moments of order q of the total number of\nSAWs obtained by averaging over many backbone configurations display\nmultifractal behavior, i.e. different moments are dominated by different\nsubsets of the backbone. This leads to generalized coordination numbers \\mu_q\nand enhancement exponents \\gamma_q, which depend on q. Our numerical results\nsuggest that the relation \\mu_1 = p_ c \\mu between the first moment \\mu_1 and\nits regular lattice counterpart \\mu is valid.", "We consider the problem of option pricing and hedging when stock returns are\ncorrelated in time. Within a quadratic-risk minimisation scheme, we obtain a\ngeneral formula, valid for weakly correlated non-Gaussian processes. We show\nthat for Gaussian price increments, the correlations are irrelevant, and the\nBlack-Scholes formula holds with the volatility of the price increments on the\nscale of the re-hedging. For non-Gaussian processes, further non trivial\ncorrections to the `smile' are brought about by the correlations, even when the\nhedge is the Black-Scholes Delta-hedge. We introduce a compact notation which\neases the computations and could be of use to deal with more complicated\nmodels.", "The Bogoliubov - de Gennes equations are solved for the Coulomb Bose gas\ndescribing a fluid of charged bosons at finite temperature. The approach is\napplicable in the weak coupling regime and the extent of its quantitative\nusefulness is tested in the three-dimensional fluid, for which diffusion Monte\nCarlo data are available on the condensate fraction at zero temperature. The\none-body density matrix is then evaluated by the same approach for the\ntwo-dimensional fluid with e^2/r interactions, to demonstrate the presence of a\nquasi-condensate from its power-law decay with increasing distance and to\nevaluate the superfluid fraction as a function of temperature at weak coupling.", "A giant negative magnetoresistance has been observed in bulk germanium doped\nwith multiply charged deep impurities. Applying a magnetic field the resistance\nmay decrease exponentially at any orientation of the field. A drop of the\nresistance as much as about 10000% has been measured at 6 T. The effect is\nattributed to the spin splitting of impurity ground state with a very large\ng-factor in the order of several tens depending on impurity.", "Context: Planets outside our solar system transiting their host star, i. e.\nthose with an orbital inclination near 90 degree, are of special interest to\nderive physical properties of extrasolar planets. With the knowledge of the\nhost star's physical parameters, the planetary radius can be determined.\nCombined with spectroscopic observations the mass and therefore the density can\nbe derived from Doppler-measurements. Depending on the brightness of the host\nstar, additional information, e. g. about the spin-orbit alignment between the\nhost star and planetary orbit, can be obtained.\n  Aims: The last few years have witnessed a growing success of transit surveys.\nAmong other surveys, the MACHO project provided nine potential transiting\nplanets, several of them with relatively bright parent stars. The photometric\nsignature of a transit event is, however, insufficient to confirm the planetary\nnature of the faint companion. The aim of this paper therefore is a\ndetermination of the spectroscopic parameters of the host stars as well as a\ndynamical mass determination through Doppler-measurements.\n  Methods: We have obtained follow-up high-resolution spectra for five stars\nselected from the MACHO sample, which are consistent with transits of\nlow-luminosity objects. Radial velocities have been determined by means of\ncross-correlation with model spectra. The MACHO light curves have been compared\nto simulations based on the physical parameters of the system derived from the\nradial velocities and spectral analyses.\n  Aims: We show that all transit light curves of the exoplanet candidates\nanalysed in this work can be explained by eclipses of stellar objects, hence\nnone of the five transiting objects is a planet.", "Using Rossi X-ray Timing Explorer Seyfert 1 and 1.2 data spanning 9 years, we\nstudy correlations between X-ray spectral features. The sample consists of 350\ntime-resolved spectra from 12 Seyfert 1 and 1.2 galaxies. Each spectrum is\nfitted to a model with an intrinsic powerlaw X-ray spectrum produced close to\nthe central black hole that is reprocessed and absorbed by material around the\nblack hole. To test the robustness of our results, we performed Monte Carlo\nsimulations of the spectral sample. We find a complex relationship between the\niron line equivalent width (EW) and the underlying power law index (Gamma). The\ndata reveal a correlation between Gamma and EW which turns over at Gamma <~ 2,\nbut finds a weak anti-correlation for steeper photon indices. We propose that\nthis relationship is driven by dilution of a disk spectrum (which includes the\nnarrow iron line) by a beamed jet component and, hence, could be used as a\ndiagnostic of jet-dominance. In addition, our sample shows a strong correlation\nbetween the reflection fraction (R) and Gamma, but we find that it is likely\nthe result of modeling degeneracies. We also see the X-ray Baldwin effect (an\nanti-correlation between the 2-10 keV X-ray luminosity and EW) for the sample\nas a whole, but not for the individual galaxies and galaxy types.", "We quantify the effect of supernova Type Ia peculiar velocities on the\nderivation of cosmological parameters. The published distant and local Ia SNe\nused for the Supernova Legacy Survey first-year cosmology report form the\nsample for this study. While previous work has assumed that the local SNe are\nat rest in the CMB frame (the No Flow assumption), we test this assumption by\napplying peculiar velocity corrections to the local SNe using three different\nflow models. The models are based on the IRAS PSCz galaxy redshift survey, have\nvarying beta = Omega_m^0.6/b, and reproduce the Local Group motion in the CMB\nframe. These datasets are then fit for w, Omega_m, and Omega_Lambda using\nflatness or LambdaCDM and a BAO prior. The chi^2 statistic is used to examine\nthe effect of the velocity corrections on the quality of the fits. The most\nfavored model is the beta=0.5 model, which produces a fit significantly better\nthan the No Flow assumption, consistent with previous peculiar velocity\nstudies. By comparing the No Flow assumption with the favored models we derive\nthe largest potential systematic error in w caused by ignoring peculiar\nvelocities to be Delta w = +0.04. For Omega_Lambda, the potential error is\nDelta Omega_Lambda = -0.04 and for Omega_m, the potential error is Delta\nOmega_m < +0.01. The favored flow model (beta=0.5) produces the following\ncosmological parameters: w = -1.08 (+0.09,-0.08), Omega_m = 0.27 (+0.02,-0.02)\nassuming a flat cosmology, and Omega_Lambda = 0.80 (+0.08,-0.07) and Omega_m =\n0.27 (+0.02,-0.02) for a w = -1 (LambdaCDM) cosmology.", "Sunyaev-Zel'dovich (SZ) cluster surveys are considered among the most\npromising methods for probing dark energy up to large redshifts. However, their\npremise is hinged upon an accurate mass-observable relationship, which could be\naffected by the (rather poorly understood) physics of the intracluster gas. In\nthis letter, using a semi-analytic model of the intracluster gas that\naccommodates various theoretical uncertainties, I develop a Fundamental Plane\nrelationship between the observed size, thermal energy, and mass of galaxy\nclusters. In particular, I find that M ~ (Y_{SZ}/R_{SZ,2})^{3/4}, where M is\nthe mass, Y_{SZ} is the total SZ flux or thermal energy, and R_{SZ,2} is the SZ\nhalf-light radius of the cluster. I first show that, within this model, using\nthe Fundamental Plane relationship reduces the (systematic+random) errors in\nmass estimates to 14%, from 22% for a simple mass-flux relationship. Since\nmeasurement of the cluster sizes is an inevitable part of observing the SZ\nclusters, the Fundamental Plane relationship can be used to reduce the error of\nthe cluster mass estimates by ~ 34%, improving the accuracy of the resulting\ncosmological constraints without any extra cost. I then argue why our\nFundamental Plane is distinctly different from the virial relationship that one\nmay naively expect between the cluster parameters. Finally, I argue that while\nincluding more details of the observed SZ profile cannot significantly improve\nthe accuracy of mass estimates, a better understanding of the impact of\nnon-gravitational heating/cooling processes on the outskirts of the\nintracluster medium (apart from external calibrations) might be the best way to\nreduce these errors.", "Radio and X-ray observations of the relativistic jets of microquasars show\nevidence for the acceleration of particles to very high energies. Signatures of\nnon-thermal processes occurring closer in to the compact object can also be\nfound. In addition, three binaries are now established emitters of high (> 100\nMeV) and/or very high (> 100GeV) energy gamma-rays. High-energy emission can\noriginate from a microquasar jet (accretion-powered) or from a shocked pulsar\nwind (rotation-powered). I discuss the impact GLAST will have in the very near\nfuture on studies of such binaries. GLAST is expected to shed new light on the\nlink between accretion and ejection in microquasars and to enable to probe\npulsar winds on small scales in rotation-powered binaries.", "We investigate deuterium atoms adsorbed on the surface of liquid helium in\nequilibrium with a vapor of atoms of the same species. These atoms are studied\nby a sensitive optical method based on spectroscopy at a wavelength of 122 nm,\nexciting the 1S-2P transition. We present a direct measurement of the\nadsorption energy of deuterium atoms on helium and show evidence for the\nexistence of resonantly enhanced recombination of atoms residing on the surface\nto molecules.", "We propose a method to study the epoch of reionization based on the possible\nobservation of 2p--2s fine structure lines from the neutral hydrogen outside\nthe cosmological H {\\sc ii} regions enveloping QSOs and other ionizing sources\nin the reionization era. We show that for parameters typical of luminous\nsources observed at $z \\simeq 6.3$ the strength of this signal, which is\nproportional to the H {\\sc i} fraction, has a brightness temperature $\\simeq 20\n  \\mu K$ for a fully neutral medium. The fine structure line from this redshift\nis observable at $\\nu \\simeq 1 \\rm GHz$ and we discuss prospects for the\ndetection with several operational and future radio telescopes. We also compute\nthe characteristics of this signal from the epoch of recombination: the peak\nbrightness is expected to be $\\simeq 100 \\mu K$; this signal appears in the\nfrequency range 5-10 MHz. The signal from the recombination era is nearly\nimpossible to detect owing to the extreme brightness of the Galactic emission\nat these frequencies.", "We present the results from simultaneous chandra and rxte observations of the\nX-ray bright Broad-Line Radio Galaxy (BLRG) 3C 382. The long (120 ks) exposure\nwith chandra HETG allows a detailed study of the soft X-ray continuum and of\nthe narrow component of the Fe Kalpha line. The rxte PCA data are used to put\nan upper limit on the broad line component and constrain the hard X-ray\ncontinuum. A strong soft excess below 1 keV is observed in the time-averaged\nHETG spectrum, which can be parameterized with a steep power law or a thermal\nmodel. The flux variability at low energies indicates that the origin of the\nsoft excess cannot be entirely ascribed to the circumnuclear diffuse emission,\ndetected by chandra on scales of 20-30 arcsec (22-33 kpc). A narrow (sigma<90\neV) Fe Kalpha line (with EW< 100 eV) is observed by the chandra HEG. Similar\nvalues for the line parameters are measured by the rxte PCA, suggesting that\nthe contribution from a broad line component is negligible. The fact that the\nexposure is split into two observations taken three days apart allows us to\ninvestigate the spectral and temporal evolution of the source on different\ntimescales. Significant flux variability associated with spectral changes is\nobserved on timescales of hours and days. The spectral variability is similar\nto that observed in radio-quiet AGN ruling out a jet-dominated origin of the\nX-rays.", "The quantum dynamics of mesoscopic or macroscopic systems is always\ncomplicated by their coupling to many \"environmental\" modes.At low T these\nenvironmental effects are dominated by localised modes, such as nuclear and\nparamagnetic spins, and defects (which also dominate the entropy and specific\nheat). This environment, at low energies, maps onto a \"spin bath\" model. This\ncontrasts with \"oscillator bath\" models (originated by Feynman and Vernon)\nwhich describe {\\it delocalised} environmental modes such as electrons,\nphonons, photons, magnons, etc. One cannot in general map a spin bath to an\noscillator bath (or vice-versa); they constitute distinct \"universality\nclasses\" of quantum environment. We show how the mapping to spin bath models is\nmade, and then discuss several examples in detail, including moving particles,\nmagnetic solitons, nanomagnets, and SQUIDs, coupled to nuclear and paramagnetic\nspin environments. We show how to average over spin bath modes, using an\noperator instanton technique, to find the system dynamics, and give analytic\nresults for the correlation functions, under various conditions. We then\ndescribe the application of this theory to magnetic and superconducting\nsystems.Particular attention is given to recent work on tunneling magnetic\nmacromolecules, where the role of the nuclear spin bath in controlling the\ntunneling is very clear; we also discuss other magnetic systems in the quantum\nregime, and the influence of nuclear and paramagnetic spins on flux dynamics in\nSQUIDs.", "We discuss different arguments that have been raised against the viability of\nthe big trip process, reaching the conclusions that this process can actually\noccur by accretion of phantom energy onto the wormholes and that it is stable\nand might occur in the global context of a multiverse model. We finally argue\nthat the big trip does not contradict any holographic bounds on entropy and\ninformation.", "We studied in detail the optical spectrum of the post-AGB star HD56126\n(IRAS07134+1005). We use high resolution spectra (R=25000 and 60000) obtained\nwith the echelle spectrographs of the 6-m telescope. About one and a half\nthousand absorptions of neutral atoms and ions, absorption bands of C_2, CN,\nand CH molecules, and interstellar bands (DIBs) are identified in the 4010 to\n8790 AA wavelength region, and the depths and radial velocities of these\nspectral features are measured. Differences are revealed between the variations\nof the radial velocities measured from spectral features of different\nexcitation. In addition to the well-known variability of the Halpha profile, we\nfound variations in the profiles of a number of FeII, YII, and BaII lines. We\nalso produce an atlas of the spectrum of HD56126 and its comparison staralpha\nPer. The full version of the atlas is available in electronic form from\nWeb-address: http://www.sao.ru/hq/ssl/Atlas/Atlas.html", "In a previous paper (Gavignaud et al. 2006), we presented the type-1 Active\nGalactic Nuclei (AGN) sample obtained from the first epoch data of the\nVIMOS-VLT Deep Survey (VVDS). The sample consists of 130 faint, broad-line AGN\nwith redshift up to z=5 and 17.5< I <24.0, selected on the basis of their\nspectra. In this paper we present the measurement of the Optical Luminosity\nFunction up to z=3.6 derived from this sample, we compare our results with\nprevious results from brighter samples both at low and at high redshift. Our\ndata, more than one magnitude fainter than previous optical surveys, allow us\nto constrain the faint part of the luminosity function up to high redshift. By\ncombining our faint VVDS sample with the large sample of bright AGN extracted\nfrom the SDSS DR3 (Richards et al., 2006b) and testing a number of different\nevolutionary models, we find that the model which better represents the\ncombined luminosity functions, over a wide range of redshift and luminosity, is\na luminosity dependent density evolution (LDDE) model, similar to those derived\nfrom the major X-surveys. Such a parameterization allows the redshift of the\nAGN space density peak to change as a function of luminosity and explains the\nexcess of faint AGN that we find at 1.0< z <1.5. On the basis of this model we\nfind, for the first time from the analysis of optically selected samples, that\nthe peak of the AGN space density shifts significantly towards lower redshift\ngoing to lower luminosity objects. This result, already found in a number of\nX-ray selected samples of AGN, is consistent with a scenario of \"AGN cosmic\ndownsizing\", in which the density of more luminous AGN, possibly associated to\nmore massive black holes, peaks earlier in the history of the Universe, than\nthat of low luminosity ones.", "We present sensitive molecular line observations of the metal-poor blue\ncompact dwarf I Zw 18 obtained with the IRAM Plateau de Bure interferometer.\nThese data constrain the CO J=1-0 luminosity within our 300 pc (FWHM) beam to\nbe L_CO < 1 \\times 10^5 K km s^-1 pc^2 (I_CO < 1 K km s^-1), an order of\nmagnitude lower than previous limits. Although I Zw 18 is starbursting, it has\na CO luminosity similar to or less than nearby low-mass irregulars (e.g. NGC\n1569, the SMC, and NGC 6822). There is less CO in I Zw 18 relative to its\nB-band luminosity, HI mass, or star formation rate than in spiral or dwarf\nstarburst galaxies (including the nearby dwarf starburst IC 10). Comparing the\nstar formation rate to our CO upper limit reveals that unless molecular gas\nforms stars much more efficiently in I Zw 18 than in our own galaxy, it must\nhave a very low CO-to-H_2 ratio, \\sim 10^-2 times the Galactic value. We detect\n3mm continuum emission, presumably due to thermal dust and free-free emission,\ntowards the radio peak.", "We present an analysis of new Suzaku data and archival data from XMM-Newton\nof the cluster of galaxies Sersic 159-03, which has a strong soft X-ray excess\nemission component. The Suzaku observation confirms the presence of the soft\nexcess emission, but it does not confirm the presence of redshifted OVII lines\nin the cluster. Radial profiles and 2D maps derived from XMM-Newton\nobservations show that the soft excess emission has a strong peak at the\nposition of the central cD galaxy and the maps do not show any significant\nazimuthal variations. Although the soft excess emission can be fitted equally\nwell with both thermal and non-thermal models, its spatial distribution is\nneither consistent with the models of intercluster warm-hot filaments, nor with\nmodels of clumpy warm intracluster gas associated with infalling groups. Using\nthe data obtained by the XMM-Newton Reflection Grating Spectrometers we do not\nconfirm the presence of the warm gas in the cluster centre with the expected\nproperties assuming the soft excess is of thermal origin. The observed\nproperties of the soft excess emission are consistent with the non-thermal\ninterpretation. While the high density of relativistic electrons associated\nwith the peak of the soft emission in the cluster centre might have been\nprovided by an active galactic nucleus in the central cD galaxy, the underlying\npopulation might have been accelerated in diffuse shocks.", "Linear polarization in X- and gamma-rays is an important diagnostic of many\nastrophysical sources, foremost giving information about their geometry,\nmagnetic fields, and radiation mechanisms. However, very few X-ray polarization\nmeasurements have been made, and then only mono-energetic detections, whilst\nseveral objects are assumed to have energy dependent polarization signatures.\nIn this paper we investigate whether detection of energy dependent polarization\nfrom cosmic sources is possible using the Compton technique, in particular with\nthe proposed PoGOLite balloon-experiment, in the 25-100 keV range. We use\nGeant4 simulations of a PoGOLite model and input photon spectra based on Cygnus\nX-1 and accreting magnetic pulsars (100 mCrab). Effective observing times of 6\nand 35 hours were simulated, corresponding to a standard and a long duration\nflight respectively. Both smooth and sharp energy variations of the\npolarization are investigated and compared to constant polarization signals\nusing chi-square statistics. We can reject constant polarization, with energy,\nfor the Cygnus X-1 spectrum (in the hard state), if the reflected component is\nassumed to be completely polarized, whereas the distinction cannot be made for\nweaker polarization. For the accreting pulsar, constant polarization can be\nrejected in the case of polarization in a narrow energy band with at least 50%\npolarization, and similarly for a negative step distribution from 30% to 0%\npolarization.", "We simulate the motion of a massive object through a dilute Bose-Einstein\ncondensate by numerical solution of the non-linear Schr\\\"odinger equation\ncoupled to an equation of motion for the object. Under a constant applied\nforce, the object accelerates up to a maximum velocity where a vortex ring is\nformed which slows the object down. If the applied force is less than a\ncritical value, the object becomes trapped within the vortex core. We show that\nthe motion can be described using the time-independent quantum states, and use\nthese states to predict the conditions required for vortex scattering.", "An analysis of the redshift maps of galaxies and quasars has revealed\nlarge-scale self-similar skeletal structures of the Universe of the same\ntopology which had been found earlier in a wide range of phenomena, spatial\nscales and environments. The \"cartwheel\" type of structure with diameter ~ 1.5\n10^27 cm is discovered in this analysis by means of the method of multi-level\ndynamical contrasting. Similar skeletal structures in size up to 1.5 10^28 cm\nare found also in the redshift maps of quasars.", "Correlated {\\em ab initio} electronic structure calculations are reported for\nthe polymers lithium hydride chain $[LiH]_{\\infty}$ and beryllium hydride\n$[Be_{2}H_{4}]_{\\infty}$. First, employing a Wannier-function-based approach,\nthe systems are studied at the Hartree-Fock level, by considering chains\nsimulating the infinite polymers. Subsequently, for the model system\n$[LiH]_{\\infty}$, the correlation effects are computed by considering virtual\nexcitations from the occupied Hartree-Fock Wannier functions of the infinite\nchain into the complementary space of localized unoccupied orbitals, employing\na full-configuration-interaction scheme. For $[Be_{2}H_{4}]_{\\infty}$, however,\nthe electron correlation contributions to its ground state energy are\ncalculated by considering finite clusters of increasing size modelling the\nsystem. Methods such as M$\\o$ller-Plesset second-order perturbation theory and\ncoupled-cluster singles, doubles and triples level of theory were employed.\nEquilibrium geometry, cohesive energy and polymerization energy are presented\nfor both polymers, and the rapid convergence of electron correlation effects,\nwhen based upon a localized orbital scheme, is demonstrated.", "We present spatial distribution of polycyclic aromatic hydrocarbons and\nionized gas within the Galactic giant HII region NGC3603. Using the IRS\ninstrument on board the Spitzer Space Telescope, we study in particular the PAH\nemission features at ~5.7, 6.2, 7.7, 8.6, and 11.3um, and the [ArII] 6.99um,\n[NeII] 12.81um, [ArIII] 8.99um, and [SIV] 10.51um forbidden emission lines. The\nobservations probe both ionized regions and photodissociation regions. Silicate\nemission is detected close to the central cluster while silicate absorption is\nseen further away. We find no significant variation of the PAH ionization\nfraction across the whole region. The emission of very small grains lies closer\nto the central stellar cluster than emission of PAHs. The PAH/VSG ratio\nanticorrelates with the hardness of the interstellar radiation field suggesting\na destruction mechanism of the molecules within the ionized gas, as shown for\nlow-metallicity galaxies by Madden et al. (2006).", "We present ACS/HST coronagraphic observations of HD 100546, a B9.5 star, 103\npc away from the sun, taken in the F435W, F606W, and F814W bands. Scattered\nlight is detected up to 14'' from the star. The observations are consistent\nwith the presence of an extended flattened nebula with the same inclination as\nthe inner disk. The well-known ``spiral arms'' are clearly observed and they\ntrail the rotating disk material. Weaker arms never before reported are also\nseen. The inter-arm space becomes brighter, but the structures become more\nneutral in color at longer wavelengths, which is not consistent with models\nthat assume that they are due to the effects of a warped disk. Along the major\ndisk axis, the colors of the scattered-light relative to the star are \\Delta\n(F435W-F606W) ~ 0.0--0.2 mags and \\Delta (F435W-F814W)~0.5--1 mags. To explain\nthese colors, we explore the role of asymmetric scattering, reddening, and\nlarge minimum sizes on ISM-like grains. We conclude each of these hypotheses by\nitself cannot explain the colors. The disk colors are similar to those derived\nfor Kuiper Belt objects, suggesting that the same processes responsible for\ntheir colors may be at work here. We argue that we are observing only the\ngeometrically thick, optically thin envelope of the disk, while the optically\nthick disk responsible for the far-IR emission is undetected. The observed\nspiral arms are then structures on this envelope. The colors indicate that the\nextended nebulosity is not a remnant of the infalling envelope but reprocessed\ndisk material.", "The melting parameter $\\Gamma_m$ of a classical one-component plasma is\nestimated using a relation between melting temperature, density, shear modulus,\nand crystal coordination number that follows from our model of\ndislocation-mediated melting. We obtain $\\Gamma_m=172\\pm 35,$ in good agreement\nwith the results of numerous Monte-Carlo calculations.", "We study numerically an electronic transport in strongly anisotropic weakly\ndisorderd two-dimensional systems. We find that the conductance distribution is\ngaussian but the conductance fluctuations increase when anisotropy becomes\nstronger. We interpret this result by random matrix theory with non-integer\nsymmetry parameter beta, in accordance with recent theoretical work of\nK.A.Muttalib and J.R.Klauder [Phys.Rev.Lett. 82 (1999) 4272]. Analysis of the\nstatistics of transport paramateres supports this hypothesis.", "We consider an atomic Bose-Einstein condensate held within an optical cavity\nand interacting with laser fields. We show how the interaction of the cavity\nmode with the condensate can cause energy due to excitations to be coupled to a\nlossy cavity mode, which then decays, thus damping the condensate, how to\nchoose parameters for damping specific excitations, and how to target a range\nof different excitations to potentially produce extremely cold condensates.", "The zero temperature relaxational dynamics of a particle in a short range\ncorrelated random potential is addressed. We derive a set of \"two-times\"\nmean-field dynamical equations, accounting for a possible mean displacement of\nthe particle when subject to an external force. We show first detailed results\nfrom the numerical integration of the above mentionned equations. We mainly pay\nattention to the exponentially decreasing spatial correlations case, for which\nsimple analytical arguments provide valuable results about the hessian of the\nenergy landscape, and we propose a geometrical description of the \"mean-field\naging\". Our numerical results and further analytical arguments give access to\nthe waiting time dependence of the main characteristic time scales.", "Recent observations have demonstrated a significant growth in the integrated\nstellar mass of the red sequence since z=1, dominated by a steadily increasing\nnumber of galaxies with stellar masses M* < 10^11 M_sun. In this paper, we use\nthe COMBO-17 photometric redshift survey in conjunction with deep Spitzer 24\nmicron data to explore the relationship between star formation and the growth\nof stellar mass. We calculate `star formation rate functions' in four different\nredshift slices, splitting also into contributions from the red sequence and\nblue cloud for the first time. We find that the growth of stellar mass since\nz=1 is consistent with the integrated star formation rate. Yet, most of the\nstars formed are in blue cloud galaxies. If the stellar mass already in, and\nformed in, z<1 blue cloud galaxies were to stay in the blue cloud the total\nstellar mass in blue galaxies would be dramatically overproduced. We explore\nthe expected evolution of stellar mass functions, finding that in this picture\nthe number of massive M* > 3x10^10 M_sun blue galaxies would also be\noverproduced; i.e., most of the new stars formed in blue cloud galaxies are in\nthe massive galaxies. We explore a simple truncation scenario in which these\n`extra' blue galaxies have their star formation suppressed by an unspecified\nmechanism or mechanisms; simple cessation of star formation in these extra blue\ngalaxies is approximately sufficient to build up the red sequence at M*<10^11\nM_sun.", "In this paper, we show that pair-correlations may play an important role in\nthe quantum statistical properties of a Bose-Einstein condensed gas composed of\nan atomic field resonantly coupled with a corresponding field of molecular\ndimers. Specifically, pair-correlations in this system can dramatically modify\nthe coherent and incoherent transfer between the atomic and molecular fields.", "We introduce a class of exactly solvable models which exhibit an ordering\nnoise-induced phase transition driven by an entropic mechanism. In contrast\nwith previous studies, order does not appear in this case as a result of an\ninstability of the disordered phase produced by noise, but of a balance between\nthe relaxing deterministic dynamics and the randomizing (entropic) character of\nthe fluctuations. A finite-size scaling analysis of the phase transition\nreveals that it belongs to the universality class of the equilibrium Ising\nmodel. All these results are analyzed in the light of the nonequilibrium\nprobability distribution of the system, which can be derived analytically. The\nrelevance of our result as a possible scenario of the so-called Lower Critical\nSolution Temperature (LCST) transitions is analysed.", "Infrared-Faint Radio Sources represent a new and unexpected class of object\nwhich is bright at radio wavelengths but unusually faint at infrared\nwavelengths. If, like most mJy radio sources, they were either conventional\nactive or star-forming galaxies in the local Universe, we would expect them to\nbe detectable at infrared wavelengths, and so their non-detection by the\nSpitzer Space Telescope is surprising. Here we report the detection of one of\nthese sources using Very Long Baseline Interferometry, from which we conclude\nthat the sources are driven by Active Galactic Nuclei. We suggest that these\nsources are either normal radio-loud quasars at high redshift or abnormally\nobscured radio galaxies.", "We present measurements of the two-point galaxy angular correlation function\nw(\\theta) in the COSMOS field. Independent determinations of w(\\theta) as a\nfunction of magnitude limit are presented for both the HST ACS catalog and also\nfor the ground-based data from Subaru and the CFHT. Despite having\nsignificantly different masks, these three determinations agree well. At bright\nmagnitudes (IAB<22), our data generally match very well with existing\nmeasurements and with mock catalogs based on semi-analytic galaxy formation\ncalculations of Kitzbichler and White from the Millennium Simulation. The\nexception is that our result is at the upper end of the expected cosmic\nvariance scatter for \\theta > 10 arcmin, which we attribute to a particularly\nrich structure known to exist at z~0.8. For fainter samples, however, the level\nof clustering is somewhat higher than reported by some previous studies: in all\nthree catalogues we find w(\\theta=1')~0.014 at a median IAB magnitude of 24. At\nthese very faintest magnitudes, our measurements agree well with the latest\ndeterminations from the Canada-France Legacy Survey. This level of clustering\nis approximately double what is predicted by the semi-analytic catalogs (at all\nangles). The semi-analytic results allow an estimate of cosmic variance, which\nis too small to account for the discrepancy. We therefore conclude that the\nmean amplitude of clustering at this level is higher than previously estimated.", "We present observations of the (1,1), (2,2), (4,4) and (5,5) inversion\ntransitions of para-ammonia (NH3) and 24 GHz continuum, taken with the\nAustralia Telescope Compact Array toward 21 southern Galactic hot molecular\ncores traced by 6.7 GHz methanol maser emission. We detect NH3(1,1) emission\ntoward all 21 regions and 24 GHz continuum emission toward 12 of the regions,\nincluding 6 with no reported 8 GHz continuum counterparts. In total, we find\nthe 21 regions contain 41 NH3(1,1) cores. We extract characteristic spectra for\nevery core at each of the NH3 transitions and present both integrated intensity\nmaps and channel maps for each region. The NH3(4,4)+(5,5) emission is always\nunresolved and found at the maser position indicating that the methanol masers\nare found at the warmest part of the core. We observe large asymmetries in the\nNH3(1,1) hyperfine line profiles and conclude this is due to a number of dense,\nsmall clumps within the beam. We derive properties of the ionised gas and find\nthe 24 GHz continuum sources not detected at 8 GHz are always coincident with\nboth NH3 and methanol masers in contrast to those detected at 8 + 24 GHz which\nare generally offset from the methanol masers. We investigate the possibility\nthat the former may be hyper-compact HII regions. Finally, we separate the\ncores into five groups, based on their association with NH3, methanol maser and\ncontinuum emission. From the different physical properties of the cores in the\ngroups, we discuss the possibility that these groups may represent cores at\ndifferent evolutionary stages of the massive star formation process.", "We have discovered a long radio trail at 843 MHz which is apparently\nassociated with middle age pulsar PSR J1509-5850. The radio trail has a length\nof ~7 arcmin. In X-rays, Chandra observations of PSR J1509-5850 reveal an\nassociated X-ray trail which extends in the same orientation as the radio\ntrail. Moreover, two clumpy structures are observed along the radio trail. The\nlarger one is proposed to be the supernova remnant (SNR) candidate MSC\n319.9-0.7. Faint X-ray enhancement at the position of the SNR candidate is\nfound in the Chandra data.", "Red clump giant stars can be used as distance indicators to trace the mass\ndistribution of the Galactic bar. We use RCG stars from 44 bulge fields from\nthe OGLE-II microlensing collaboration database to constrain analytic tri-axial\nmodels for the Galactic bar. We find the bar major axis is oriented at an angle\nof 24 - 27 degrees to the Sun-Galactic centre line-of-sight. The ratio of\nsemi-major and semi-minor bar axis scale lengths in the Galactic plane x_0,\ny_0, and vertical bar scale length z_0, is x_0 : y_0 : z_0 = 10 : 3.5 : 2.6,\nsuggesting a slightly more prolate bar structure than the working model of\nGerhard (2002) which gives the scale length ratios as x_0 : y_0 : z_0 = 10 : 4\n: 3 .", "The renormalization group has played an important role in the physics of the\nsecond half of the twentieth century both as a conceptual and a calculational\ntool. In particular it provided the key ideas for the construction of a\nqualitative and quantitative theory of the critical point in phase transitions\nand started a new era in statistical mechanics. Probability theory lies at the\nfoundation of this branch of physics and the renormalization group has an\ninteresting probabilistic interpretation as it was recognized in the middle\nseventies. This paper intends to provide a concise introduction to this aspect\nof the theory of phase transitions which clarifies the deep statistical\nsignificance of critical universality.", "The Energetic Gamma-Ray Experiment Telescope (EGRET) on the Compton Gamma-Ray\nObservatory (CGRO) discovered gamma-ray emission from more than 67 blazars\nduring its 9 yr lifetime. We conducted an exhaustive search of the EGRET\narchives and selected all the blazars that were observed multiple times and\nwere bright enough to enable a spectral analysis using standard power-law\nmodels. The sample consists of 18 flat-spectrum radio quasars(FSRQs), 6\nlow-frequency peaked BL Lac objects (LBLs) and 2 high-frequency peaked BL Lac\nobjects (HBLs). We do not detect any clear pattern in the variation of spectral\nindex with flux. Some of the blazars do not show any statistical evidence for\nspectral variability. The spectrum hardens with increasing flux in a few cases.\nThere is also evidence for a flux-hardness anticorrelation at low fluxes in\nfive blazars. The well-observed blazars (3C 279, 3C 273, PKS 0528+134, PKS\n1622-297 PKS 0208-512) do not show any overall trend in the long-term spectral\ndependence on flux, but the sample shows a mixture of hard and soft states. We\nobserved a previously unreported spectral hysteresis at weekly timescales in\nall three FSRQs for which data from flares lasting for ~(3-4) weeks were\navailable. All three sources show a counterclockwise rotation, despite the\nwidely different flux profiles. We analyze the observed spectral behavior in\nthe context of various inverse Compton mechanisms believed to be responsible\nfor emission in the EGRET energy range. Our analysis uses the EGRET skymaps\nthat were regenerated to include the changes in performance during the mission.", "We consider the orbit of the bullet cluster 1E 0657-56 in both CDM and MOND\nusing accurate mass models appropriate to each case in order to ascertain the\nmaximum plausible collision velocity. Impact velocities consistent with the\nshock velocity (~ 4700km/s) occur naturally in MOND. CDM can generate collision\nvelocities of at most ~ 3800km/s, and is only consistent with the data provided\nthat the shock velocity has been substantially enhanced by hydrodynamical\neffects.", "The dynamical behavior of Bose-Einstein condensation (BEC) in a gas with\nattractive interactions is striking. Quantum theory predicts that BEC of a\nspatially homogeneous gas with attractive interactions is precluded by a\nconventional phase transition into either a liquid or solid. When confined to a\ntrap, however, such a condensate can form provided that its occupation number\ndoes not exceed a limiting value. The stability limit is determined by a\nbalance between self-attraction and a repulsion arising from position-momentum\nuncertainty under conditions of spatial confinement. Near the stability limit,\nself-attraction can overwhelm the repulsion, causing the condensate to\ncollapse. Growth of the condensate, therefore, is punctuated by intermittent\ncollapses, which are triggered either by macroscopic quantum tunneling or\nthermal fluctuation. Previous observation of growth and collapse has been\nhampered by the stochastic nature of these mechanisms. Here we reduce the\nstochasticity by controlling the initial number of condensate atoms using a\ntwo-photon transition to a diatomic molecular state. This enables us to obtain\nthe first direct observation of the growth of a condensate with attractive\ninteractions and its subsequent collapse.", "We present the results of a detailed spectral and temporal analysis of Swift\nand XMM-Newton observations of the high redshift (z=3.969) GRB 050730. The\nX-ray afterglow of GRB 050730 was found to decline with time with superimposed\nintense flaring activity that extended over more than two orders of magnitude\nin time. Seven distinct re-brightening events starting from 236 s up to 41.2 ks\nafter the burst were observed. The underlying decay of the afterglow was well\ndescribed by a double broken power-law model with breaks at t_1= 237 +/- 20 s\nand t_2 = 10.1 (-2.2) (+4.6) ks. The temporal decay slopes before, between and\nafter these breaks were alpha_1 = 2.1 +/- 0.3, alpha_2 = 0.44 (-0.08) (+0.14)\nand alpha_3 = 2.40 (+0.07) (-0.09), respectively. The spectrum of the X-ray\nafterglow was well described by a photoelectrically absorbed power-law with an\nabsorbing column density N_H=(1.28 +/- 0.26) 10^22 cm^-2 in the host galaxy.\nStrong X-ray spectral evolution during the flaring activity was present. In the\nmajority of the flares (6/7) the ratio Delta_t/t_p between the duration of the\nevent and the time when the flare peaks was nearly constant and about 0.6-0.7.\nWe showed that the observed spectral and temporal properties of the first three\nflares are consistent with being due both to high-latitude emission, as\nexpected if the flares were produced by late internal shocks, or to refreshed\nshocks, i.e. late time energy injections into the main afterglow shock by slow\nmoving shells ejected from the central engine during the prompt phase. The\nevent fully satisfies the E_p-E_iso Amati relation while is not consistent with\nthe E_p-E_jet Ghirlanda relation.", "Context. Swift data are revolutionising our understanding of Gamma Ray\nBursts. Since bursts fade rapidly, it is desirable to create and disseminate\naccurate light curves rapidly.\n  Aims. To provide the community with an online repository of X-ray light\ncurves obtained with Swift. The light curves should be of the quality expected\nof published data, but automatically created and updated so as to be\nself-consistent and rapidly available. Methods. We have produced a suite of\nprograms which automatically generates Swift/XRT light curves of GRBs. Effects\nof the damage to the CCD, automatic readout-mode switching and pile-up are\nappropriately handled, and the data are binned with variable bin durations, as\nnecessary for a fading source.\n  Results. The light curve repository website\n(http://www.swift.ac.uk/xrt_curves) contains light curves, hardness ratios and\ndeep images for every GRB which Swift's XRT has observed. When new GRBs are\ndetected, light curves are created and updated within minutes of the data\narriving at the UK Swift Science Data Centre.", "This is based on 4 lectures given at the 13th Australian Physics Summer\nSchool, Australia National University, Canberra, Jan 17-28, 2000. The main\ntopic is the theory of collective modes in a trapped Bose gas at finite\ntemperatures. A generalized Gross-Pitaevskii equation is derived at finite\ntemperatures, which is used to discuss a new mechanism for damping in the\ncollisionless region arising from interactions with a static thermal cloud of\nnon-condensate atoms. Next, introducing a kinetic equation for the thermal\ncloud, we derive two-fluid equations of motion for the condensate and\nnon-condensate components in the collision-dominated hydrodynamic region. We\nshow that these are precisely the equivalent of the Landau two-fluid equations\nin the limit that the two components are in diffusive local equilibrium.\nHowever, our equations also predict the existence of a new zero frequency\nrelaxational mode, in addition to the usual Landau hydrodynamic modes (such as\nfirst and second sound). The special importance and simplicity of two-fluid\nhydrodynamics is stressed.", "Cosmological shock waves result from supersonic flow motions induced by\nhierarchical clustering of nonlinear structures in the universe. These shocks\ngovern the nature of cosmic plasma through thermalization of gas and\nacceleration of nonthermal, cosmic-ray (CR) particles. We study the statistics\nand energetics of shocks formed in cosmological simulations of a concordance\n$\\Lambda$CDM universe, with a special emphasis on the effects of\nnon-gravitational processes such as radiative cooling, photoionization/heating,\nand galactic superwind feedbacks. Adopting an improved model for gas\nthermalization and CR acceleration efficiencies based on nonlinear diffusive\nshock acceleration calculations, we then estimate the gas thermal energy and\nthe CR energy dissipated at shocks through the history of the universe. Since\nshocks can serve as sites for generation of vorticity, we also examine the\nvorticity that should have been generated mostly at curved shocks in\ncosmological simulations. We find that the dynamics and energetics of shocks\nare governed primarily by the gravity of matter, so other non-gravitational\nprocesses do not affect significantly the global energy dissipation and\nvorticity generation at cosmological shocks. Our results reinforce scenarios in\nwhich the intracluster medium and warm-hot intergalactic medium contain\nenergetically significant populations of nonthermal particles and turbulent\nflow motions.", "We present theoretically-established values of the CO-to-H2 and C-to-H2\nconversion factors that may be used to estimate the gas masses of external\ngalaxies. We consider four distinct galaxy types, represented by M51, NGC 6946,\nM82 and SMC N27. The physical parameters that best represent the conditions\nwithin the molecular clouds in each of the galaxy types are estimated using a\nchi^2 analysis of several observed atomic fine structure and CO rotational\nlines. This analysis is explored over a wide range of density, radiation field,\nextinction, and other relevant parameters. Using these estimated physical\nconditions in methods that we have previously established, CO-to-H2 conversion\nfactors are then computed for CO transitions up to J=9-8. For the conventional\nCO(1-0) transition, the computed conversion factor varies significantly below\nand above the canonical value for the Milky Way in the four galaxy types\nconsidered. Since atomic carbon emission is now frequently used as a probe of\nexternal galaxies, we also present, for the first time, the C-to-H2 conversion\nfactor for this emission in the four galaxy types considered.", "The phase diagram of a stack of tensionless membranes with nonlinear\ncurvature energy and vertical harmonic interaction is calculated exactly in a\nlarge number of dimensions of configuration space. At low temperatures, the\nsystem forms a lamellar phase with spontaneously broken translational symmetry\nin the vertical direction. At a critical temperature, the stack disorders\nvertically in a melting-like transition. The critical temperature is determined\nas a function of the interlayer separation l.", "A major goal in solar physics has during the last five decades been to find\nhow energy flux generated in the solar convection zone is transported and\ndissipated in the outer solar layers. Progress in this field has been slow and\npainstaking. However, advances in computer hardware and numerical methods,\nvastly increased observational capabilities and growing physical insight seem\nfinally to be leading towards understanding. Here we present exploratory\nnumerical MHD models that span the entire solar atmosphere from the upper\nconvection zone to the lower corona. These models include non-grey, non-LTE\nradiative transport in the photosphere and chromosphere, optically thin\nradiative losses as well as magnetic field-aligned heat conduction in the\ntransition region and corona.", "We explore how the spiral spin(SP) state, a spin singlet known to accompany\nfully-polarized ferromagnetic (F) states in the Hubbard model, is related with\nthe F state in the thermodynamic limit using the density matrix renormalization\ngroup and exact diagonalization. We first obtain an indication that when the F\nstate is the ground state the SP state is also eligible as the ground state in\nthat limit. We then follow the general argument by Koma and Tasaki [J. Stat.\nPhys. {\\bf 76}, 745 (1994)] to find that: (i) The SP state possesses a kind of\norder parameter. (ii) Although the SP state does not break the SU(2) symmetry\nin finite systems, it does so in the thermodynamic limit by making a linear\ncombination with other states that are degenerate in that limit. We also\ncalculate the one-particle spectral function and dynamical spin and charge\nsusceptibilities for various 1D finite-size lattices. We find that the\nexcitation spectrum of the SP state and the F state is almost identical. Our\npresent results suggest that the SP and the F states are equivalent in the\nthermodynamic limit. These properties may be exploited to determine the\nmagnetic phase diagram from finite-size studies.", "This work reports on the systematic high pressure Raman studies in the\nPbZr$_{1-x}$Ti$_x$O$_3$ ($0.02 \\leq x \\leq 0.14$) ceramics performed at room\ntemperature. The pressure dependence of the Raman spectra reveals the stable\nphases of the material under pressure variation. The results allowed us to\npropose a concentration-pressure phase diagram for rich Zr PZT system up to\npressures of 5.0 GPa.", "We present the first strong lensing study of the mass distribution in the\ncluster MS 2053-04 based on HST archive data. This massive, X-ray luminous\ncluster has a redshift z=0.583, and it is composed of two structures that are\ngravitationally bound to each other. The cluster has one multiply imaged system\nconstituted by a double gravitational arc.\n  We have performed a parametric strong lensing mass reconstruction using NFW\ndensity profiles to model the cluster potential. We also included perturbations\nfrom 23 galaxies, modeled like elliptical singular isothermal sphere, that are\napproximately within 1'x1' around the cluster center. These galaxies were\nconstrained in both the geometric and dynamical parameters with observational\ndata. Our analysis predicts a third image which is slightly demagnified. We\nfound a candidate for this counter-image near the expected position and with\nthe same F702W-F814W colors as the gravitational arcs in the cluster. The\nresults from the strong lensing model shows the complex structure in this\ncluster, the asymmetry and the elongation in the mass distribution, and are\nconsistent with previous spectrophotometric results that indicate that the\ncluster has a bimodal mass distribution. Finally, the derived mass profile was\nused to estimate the mass within the arcs and for comparison with X-ray\nestimates.", "The trapping of excitons in a semiconductor quantum well due to a circular\nsymmetric nonhomogeneous magnetic field is studied. The effect of the spin\nstate of the exciton on its trapping energy is analyzed, and the importance of\nthe interaction of the orbital and spin Zeeman effect as compared to the\ndiamagnetic term in the exciton Hamiltonian is emphasized. Magnetic field\nprofiles are considered, which can experimentally be created through the\ndeposition of ferromagnetic disks on top of a semiconductor heterostructure.\nThis setup gives rise to a magnetic dipole type of profile in the $xy$ plane of\nthe exciton motion. We find that the spin direction of the exciton influences\nits localization by changing the confinement region in the effective potential.\nThe exciton confinement increases with magnetic field intensity, and this is\nmore pronounced when the exciton g-factor is different from zero. The numerical\ncalculations are performed for GaAs/Al$_{x}$Ga$_{1-x}$As quantum wells and we\nshow that it open up a new realistic path for experiments designed to probe\nexciton trapping in semiconductors.", "We propose a scheme for the creation of skyrmions (coreless vortices) in a\nBose-Einstein condensate with hyperfine spin F=1. In this scheme, four\ntraveling-wave laser beams, with Gaussian or Laguerre-Gaussian transverse\nprofiles, induce Raman transitions with an anomalous dependence on the laser\npolarization, thereby generating the optical potential required for producing\nskyrmions.", "We consider the nonminimally coupled lambda phi^4 scalar field theory in de\nSitter space and construct the renormalization group improved renormalized\neffective theory at the one-loop level. Based on the corresponding quantum\nFriedmann equation and the scalar field equation of motion, we calculate the\nquantum radiative corrections to the scalar spectral index n_s, gravitational\nwave spectral index n_g and the ratio r of tensor to scalar perturbations. When\ncompared with the standard (tree-level) values, we find that the quantum\ncontributions are suppressed by lambda N^2 where N denotes the number of\ne-foldings. Hence there is an N^2 enhancement with respect to the naive\nexpectation, which is due to the infrared enhancement of scalar vacuum\nfluctuations characterising de Sitter space. Since observations constrain\nlambda to be very small lambda ~ 10^(-12) and N ~ 50-60, the quantum\ncorrections in this inflationary model are unobservably small.", "Transiting extrasolar planets are now discovered jointly by photometric\nsurveys and by radial velocimetry. We want to determine whether the different\ndata sets are compatible between themselves and with models of the evolution of\nextrasolar planets. We simulate directly a population of stars corresponding to\nthe OGLE transit survey and assign them planetary companions based on radial\nvelocimetry discoveries. We use a model of the evolution and structure of giant\nplanets assuming a variable fraction of heavy elements. The output list of\ndetectable planets of the simulations is compared to the real detections. We\nconfirm that the radial velocimetry and photometric survey data sets are\ncompatible within the statistical errors, assuming that planets with periods\nbetween 1 and 2 days are approximately 5 times less frequent than planets with\nperiods between 2 and 5 days. We show that evolution models fitting present\nobservational constraints predict a lack of small giant planets with large\nmasses. We also identify distinct populations of planets: those with short\nperiods (P < 10d) are only found in orbit around metal-rich stars with [Fe/H] >\n-0.07. We further confirm the relative absence of low-mass giant planets at\nsmall orbital distances.", "High-resolution spectroscopy of U Gem was obtained during quiescence. We did\nnot find a hot spot or gas stream around the outer boundaries of the accretion\ndisk. Instead, we detected a strong narrow emission near the location of the\nsecondary star. We measured the radial velocity curve from the wings of the\ndouble-peaked H$\\alpha$ emission line, and obtained a semi-amplitude value that\nis in excellent agreement with the obtained from observations in the\nultraviolet spectral region by Sion et al. (1998). We present also a new method\nto obtain K_2, which enhances the detection of absorption or emission features\narising in the late-type companion. Our results are compared with published\nvalues derived from the near-infrared NaI line doublet. From a comparison of\nthe TiO band with those of late type M stars, we find that a best fit is\nobtained for a M6V star, contributing 5 percent of the total light at that\nspectral region. Assuming that the radial velocity semi-amplitudes reflect\naccurately the motion of the binary components, then from our results: K_em =\n107+/-2 km/s; K_abs = 310+/-5 km/s, and using the inclination angle given by\nZhang & Robinson(1987); i = 69.7+/-0.7, the system parameters become: M_WD =\n1.20+/-0.05 M_sun,; M_RD = 0.42+/-0.04 M_sun; and a = 1.55+/- 0.02 R_sun. Based\non the separation of the double emission peaks, we calculate an outer disk\nradius of R_out/a ~0.61, close to the distance of the inner Lagrangian point\nL_1/a~0.63. Therefore we suggest that, at the time of observations, the\naccretion disk was filling the Roche-Lobe of the primary, and that the matter\nleaving the L_1 point was colliding with the disc directly, producing the hot\nspot at this location.", "Motivated by some recent criticisms to our alternative Langevin equation for\ndriven lattice gases (DLG) under an infinitely large driving field, we revisit\nthe derivation of such an equation, and test its validity. As a result, an\nadditional term, coming from a careful consideration of entropic contributions,\nis added to the equation. This term heals all the recently reported generic\ninfrared singularities.\n  The emerging equation is then identical to that describing randomly driven\ndiffusive systems. This fact confirms our claim that the infinite driving limit\nis singular, and that the main relevant ingredient determining the critical\nbehavior of the DLG in this limit is the anisotropy and not the presence of a\ncurrent. Different aspects of our picture are discussed, and it is concluded\nthat it constitutes a very plausible scenario to rationalize the critical\nbehavior of the DLG and variants of it.", "We present a geometrical description of new canonical $d$-dimensional\ncodimension one quasiperiodic tilings based on generalized Fibonacci sequences.\nThese tilings are made up of rhombi in 2d and rhombohedra in 3d as the usual\nPenrose and icosahedral tilings. Thanks to a natural indexing of the sites\naccording to their local environment, we easily write down, for any\napproximant, the sites coordinates, the connectivity matrix and we compute the\nstructure factor.", "We solve the Boltzmann equation for electrons moving in a two-dimensional\nplane of square symmetry in the presence of a transverse magnetic field. We\nassume that there are two sources of scattering: a large momentum-independent\nscattering on a collective mode of the electron system, and a smaller\nmomentum-dependent forward scattering on impurities. We show that the effect of\nimpurities on the longitudinal and Hall conductivities is of the same order of\nmagnitude.", "The problem of the observable equilibrium domain structure in pure\nantiferromagnets (and other thermoelastics) is investigated with the use of\ncontinuous elasticity theory. It is shown that completely rigid surface\nproduces the imaginary ``incompatibility elastic charges'' analogous to the\nsurface magnetic charges in ferromagnets. Corresponding long-range field is\nshown to contribute into the ``stray'' energy of the sample that governs an\nappearance of the domain structure, the contribution from the ``elastic\ncharges'' being proportional to the sample volume. Competition between the\nelastic ``stray'' field that favors inhomogeneous strain distribution, and\nexternal field that tends to homogenize the sample, provides the reversible\nreconstruction of the domain structure under the action of external magnetic\nfield.", "Interstellar neutral hydrogen (HI) emission spectra manifest several families\nof linewidths whose numerical values (34, 13 & 6 km/s) appear to be related to\nthe critical ionization velocities (CIVs) of the most abundant interstellar\natomic species. Extended new analysis of HI emission profiles shows that the 34\nkm/s wide component, probably corresponding to the CIV for helium, is\npervasive. The 34 km/s wide linewidth family is found in low-velocity (local)\nneutral hydrogen (HI) profiles as well as in the so-called high-velocity\nclouds. In addition, published studies of HI linewidths found in the Magellanic\nStream, Very-High-Velocity Clouds, and Compact High-Velocity Clouds, all of\nwhich are believed to be intergalactic, have noted that typical values are of\nthe same order. If the critical ionization velocity effect does play a role in\ninterstellar space it may be expected to produce locally enhanced electron\ndensities where rapidly moving neutral gas masses interact with surrounding\nplasma. Evidence is presented that suggests that this phenomenon is occurring\nin interstellar space. It manifests as a spatial association between peaks in\nHI structure offset with respect to peaks in high-frequency radio continuum\ndata obtained with the Wilkinson Microwave Anisotropy Probe.", "The very nature of the solar chromosphere, its structuring and dynamics,\nremains far from being properly understood, in spite of intensive research.\nHere we point out the potential of chromospheric observations at millimeter\nwavelengths to resolve this long-standing problem. Computations carried out\nwith a sophisticated dynamic model of the solar chromosphere due to Carlsson\nand Stein demonstrate that millimeter emission is extremely sensitive to\ndynamic processes in the chromosphere and the appropriate wavelengths to look\nfor dynamic signatures are in the range 0.8-5.0 mm. The model also suggests\nthat high resolution observations at mm wavelengths, as will be provided by\nALMA, will have the unique property of reacting to both the hot and the cool\ngas, and thus will have the potential of distinguishing between rival models of\nthe solar atmosphere. Thus, initial results obtained from the observations of\nthe quiet Sun at 3.5 mm with the BIMA array (resolution of 12 arcsec) reveal\nsignificant oscillations with amplitudes of 50-150 K and frequencies of 1.5-8\nmHz with a tendency toward short-period oscillations in internetwork and longer\nperiods in network regions. However higher spatial resolution, such as that\nprovided by ALMA, is required for a clean separation between the features\nwithin the solar atmosphere and for an adequate comparison with the output of\nthe comprehensive dynamic simulations.", "A generalized supersymmetric representation of the Hubbard operator algebra\nis considered. This representation is applied to the infinite-U Hubbard model.\nA mean-field theory which takes into account both on-site and inter-site\nvirtual boson-fermion transitions is developed. Unlike previous approaches, the\nmean-field theory considered is free from divergences. Possible application of\nthese results to the ferromagnet-paramagnet transition, as well as to other\nproblems is discussed.", "We present excellent resolution and high sensitivity Very Large Array (VLA)\nobservations of the 21cm HI line emission from the face-on galaxy NGC 1058,\nproviding the first reliable study of the HI profile shapes throughout the\nentire disk of an external galaxy. Our observations show an intriguing picture\nof the interstellar medium; throughout this galaxy velocity-- dispersions range\nbetween 4 to 15 km/sec but are not correlated with star formation, stars or the\ngaseous spiral arms. The velocity dispersions decrease with radius, but this\nglobal trend has a large scatter as there are several isolated, resolved\nregions of high dispersion. The decline of star light with radius is much\nsteeper than that of the velocity dispersions or that of the energy in the gas\nmotions.", "Stereoscopic spectral imaging is an observing technique that affords rapid\nacquisition of limited spectral information over an entire image plane\nsimultaneously. Light from a telescope is dispersed into multiple spectral\norders, which are imaged separately, and two or more of the dispersed images\nare combined using an analogy between the (x,y,\\lambda) spectral data space and\nconventional (x,y,z) three-space. Because no photons are deliberately destroyed\nduring image acquisition, the technique is much more photon-efficient in some\nobserving regimes than existing techniques such as scanned-filtergraph or\nscanned-slit spectral imaging. Hybrid differential stereoscopy, which uses a\ncombination of conventional cross-correlation stereoscopy and linear\napproximation theory to extract the central wavelength of a spectral line, has\nbeen used to produce solar Stokes-V (line-of-sight) magnetograms in the 617.34\nnm Fe I line, and more sophisticated inversion techniques are currently being\nused to derive Doppler and line separation data from EUV images of the solar\ncorona collected in the neighboring lines of He-II and Si-XI at 30.4 nm. In\nthis paper we develop an analytic a priori treatment of noise in the line shift\nsignal derived from hybrid differential stereoscopy. We use the analysis to\nestimate the noise level and measurement precision in a high resolution solar\nmagnetograph based on stereoscopic spectral imaging, compare those estimates to\na test observation made in 2003, and discuss implications for future\ninstruments.", "We explore the effect of an inhomogeneous mass density field on frequencies\nand wave profiles of torsional Alfven oscillations in solar coronal loops.\nDispersion relations for torsional oscillations are derived analytically in\nlimits of weak and strong inhomogeneities. These analytical results are\nverified by numerical solutions, which are valid for a wide range of\ninhomogeneity strength. It is shown that the inhomogeneous mass density field\nleads to the reduction of a wave frequency of torsional oscillations, in\ncomparison to that of estimated from mass density at the loop apex. This\nfrequency reduction results from the decrease of an average Alfven speed as far\nas the inhomogeneous loop is denser at its footpoints. The derived dispersion\nrelations and wave profiles are important for potential observations of\ntorsional oscillations which result in periodic variations of spectral line\nwidths. Torsional oscillations offer an additional powerful tool for a\ndevelopment of coronal seismology.", "We have studied molecular hydrogen in a pure 1D geometry and inside a narrow\ncarbon nanotube by means of the diffusion Monte Carlo method. The\none-dimensionality of H2 in the nanotube is well maintained in a large density\nrange, this system being closer to an ideal 1D fluid than liquid 4He in the\nsame setup. H2 shares with 4He the existence of a stable liquid phase and a\nquasi-continuous liquid-solid transition at very high linear densities.", "The possibility of a second pairing transition $d\\to d+is$ ($d+id^\\prime$) in\nplanar $d$-wave superconductors which occurs in the absence of external\nmagnetic field, magnetic impurities or boundaries is established in the\nframework of the non-perturbative phenomenon of dynamical chiral symmetry\nbreaking in the system of $2+1$-dimensional Dirac-like nodal quasiparticles. We\ndetermine the critical exponents and quasiparticle spectral functions that\ncharacterize the corresponding quantum critical behavior and discuss some of\nits potentially observable spectral and transport features.", "In this paper, we present a new implementation of feedback due to active\ngalactic nuclei (AGN) in cosmological simulations of galaxy formation. We\nassume that a fraction of jet energy, which is generated by an AGN, is\ntransferred to the surrounding gas as thermal energy. Combining a theoretical\nmodel of mass accretion onto black holes with a multiphase description of\nstar-forming gas, we self-consistently follow evolution of both galaxies and\ntheir central black holes. The novelty in our model is that we consider two\ndistinct accretion modes: standard radiatively efficient thin accretion disks\nand radiatively inefficient accretion flows which we will generically refer to\nas RIAFs; motivated by theoretical models for jet production in accretion\ndisks, we assume that only the RIAF is responsible for the AGN feedback. We\nfind that, after an initial episode of bursting star formation, the accretion\nrate onto the central black hole drops so that the accretion disk switches to a\nRIAF structure. At this point, the feedback from the AGN becomes efficient and\nslightly suppresses star formation in the galactic disk and almost completely\nhalts star formation in the bulge. As a result, the nucleus becomes a\nstochastically fuelled low-luminosity AGN (Seyfert galaxy) with recurrent\nshort-lived episodes of activity after the star bursts. Our model predicts\nseveral properties of the low-luminosity AGN including the bolometric\nluminosity, jet powers, the effect on kpc-scale of the radio jet and the AGN\nlifetime, which are in broad agreement with observations of Seyfert galaxies\nand their radio activity. We also find that the mass ratios between the central\nblack hole and the the host spheroid at z = 0 are ~10^{-3} regardless of the\nstrength of either supernova feedback or AGN feedback. (abridged)", "We present an x-ray diffraction study of the Vanadium-doped blue bronze\nK0.3(Mo0.972V0.028)O3. At low temperature, we have observed both an intensity\nasymmetry of the +-2kF satellite reflections relative to the pure compound, and\na profile asymmetry of each satellite reflections. We show that the profile\nasymmetry is due to Friedel oscillation around the V substituant and that the\nintensity asymmetry is related to the charge density wave (CDW) pinning. These\ntwo effects, intensity and profile asymmetries, gives for the first time access\nto the local properties of CDW in disordered systems, including the pinning and\neven the phase shift of FOs.", "We study the phase behaviour of a two-dimensionally confined hard sphere\ncolloidal system in the presence of a periodic light field of two interfering\nlaser beams using Monte Carlo simulations. For a given packing fraction of the\nparticles, the colloidal system undergoes a transition from a modulated liquid\nto a modulated crystal as the light intensity is increased, corresponding to\nlaser induced freezing. For certain packing fractions of the colloidal\nparticles, the system again becomes a modulated liquid as the field strength\ncrosses a threshold value, showing a re-entrant behaviour.", "A renormalization group method is developed with which thermodynamic\nproperties of a weakly interacting, confined Bose gas can be investigated.\nThereby effects originating from a confining potential are taken into account\nby periodic boundary conditions and by treating the resulting discrete energy\nlevels of the confined degrees of freedom properly. The resulting density of\nstates modifies the flow equations of the renormalization group in momentum\nspace. It is shown that as soon as the characteristic length of confinement\nbecomes comparable to the thermal wave length of a weakly interacting and\ntrapped Bose gas its thermodynamic properties are changed significantly. This\nis exemplified by investigating characteristic bunching properties of the\ninteracting Bose gas which manifest themselves in the second order coherence\nfactor.", "Analysis of an exactly soluble model of phonons coupled to a carrier in a\nquantum dot provides a clear illustration of a phonon bottleneck to relaxation.\nThe introduction of three-phonon interactions leads to a broad window for\nrelaxation by the processes of LO phonon scattering and decay.", "A microscopic theory is developed for the projection (quantum mirage) of the\nKondo resonance from one focus of an elliptic quantum corral to the other\nfocus. The quantum mirage is shown to be independent of the size and the shape\nof the ellipse, and experiences \\lambda_F/4 oscillations (\\lambda_F is the\nsurface-band Fermi wavelength) with an increasing semimajor axis length. We\npredict an oscillatory behavior of the mirage as a function of a weak magnetic\nfield applied perpendicular to the sample.", "We set up a forward--backward path integral for a point particle in a bath of\nphotons to derive a master equation for the density matrix which describes\nelectromagnetic dissipation and decoherence. As an application, we recalculate\nthe Weisskopf-Wigner formula for the natural line width of an atomic state at\nzero temperature and find, in addition, the temperature broadening caused by\nthe decoherence term.", "We construct magnetohydrodynamic (MHD) similarity rebound shocks joining\n`quasi-static' asymptotic solutions around the central degenerate core to\nexplore an MHD model for the evolution of random magnetic field in supernova\nexplosions. This provides a theoretical basis for further studying synchrotron\ndiagnostics, MHD shock acceleration of cosmic rays, and the nature of intense\nmagnetic field in compact objects. The magnetic field strength in space\napproaches a limiting ratio, that is comparable to the ratio of the ejecta mass\ndriven out versus the progenitor mass, during this self-similar rebound MHD\nshock evolution. The intense magnetic field of the remnant compact star as\ncompared to that of the progenitor star is mainly attributed to both the\ngravitational core collapse and the radial distribution of magnetic field.", "Cooling is the main process leading to the condensation of gas in the dark\nmatter potential wells and consequently to star and structure formation. In a\nmetal-free environment, the main available coolants are H, He, H$_2$ and HD;\nonce the gas is enriched with metals, these also become important in defining\nthe cooling properties of the gas. We discuss the implementation in Gadget-2 of\nmolecular and metal cooling at temperatures lower that $\\rm10^4 K$, following\nthe time dependent properties of the gas and pollution from stellar evolution.\nWe have checked the validity of our scheme comparing the results of some test\nruns with previous calculations of cosmic abundance evolution and structure\nformation, finding excellent agreement. We have also investigated the relevance\nof molecule and metal cooling in some specific cases, finding that inclusion of\nHD cooling results in a higher clumping factor of the gas at high redshifts,\nwhile metal cooling at low temperatures can have a significant impact on the\nformation and evolution of cold objects.", "The early Solar System contained short-lived radionuclides such as 60Fe (t1/2\n= 1.5 Myr) whose most likely source was a nearby supernova. Previous models of\nSolar System formation considered a supernova shock that triggered the collapse\nof the Sun's nascent molecular cloud. We advocate an alternative hypothesis,\nthat the Solar System's protoplanetary disk had already formed when a very\nclose (< 1 pc) supernova injected radioactive material directly into the disk.\nWe conduct the first numerical simulations designed to answer two questions\nrelated to this hypothesis: will the disk be destroyed by such a close\nsupernova; and will any of the ejecta be mixed into the disk? Our simulations\ndemonstrate that the disk does not absorb enough momentum from the shock to\nescape the protostar to which it is bound. Only low amounts (< 1%) of mass loss\noccur, due to stripping by Kelvin-Helmholtz instabilities across the top of the\ndisk, which also mix into the disk about 1% of the intercepted ejecta. These\nlow efficiencies of destruction and injectation are due to the fact that the\nhigh disk pressures prevent the ejecta from penetrating far into the disk\nbefore stalling. Injection of gas-phase ejecta is too inefficient to be\nconsistent with the abundances of radionuclides inferred from meteorites. On\nthe other hand, the radionuclides found in meteorites would have condensed into\ndust grains in the supernova ejecta, and we argue that such grains will be\ninjected directly into the disk with nearly 100% efficiency. The meteoritic\nabundances of the short-lived radionuclides such as 60Fe therefore are\nconsistent with injection of grains condensed from the ejecta of a nearby (< 1\npc) supernova, into an already-formed protoplanetary disk.", "The motivations to make ultraviolet (UV) studies of supernovae (SNe) are\nreviewed and discussed in the light of the results obtained so far by means of\nIUE and HST observations. It appears that UV studies of SNe can, and do lead to\nfundamental results not only for our understanding of the SN phenomenon, such\nas the kinematics and the metallicity of the ejecta, but also for exciting new\nfindings in Cosmology, such as the tantalizing evidence for \"dark energy\" that\nseems to pervade the Universe and to dominate its energetics. The need for\nadditional and more detailed UV observations is also considered and discussed.", "We have studied the statistics of giant pulses from the Crab pulsar for the\nfirst time with particular reference to their widths. We have analyzed data\ncollected during 3.5 hours of observations conducted with the Westerbork\nSynthesis Radio Telescope operated in a tied-array mode at a frequency of 1200\nMHz. The PuMa pulsar backend provided voltage recording of X and Y linear\npolarization states in two conjugate 10 MHz bands. We restricted the time\nresolution to 4 microseconds to match the scattering on the interstellar\ninhomogeneities. In total about 18000 giant pulses (GP) were detected in full\nintensity with a threshold level of 6 sigma. Cumulative probability\ndistributions (CPD) of giant pulse energies were analyzed for groups of GPs\nwith different effective widths in the range 4 to 65 microseconds. The CPDs\nwere found to manifest notable differences for the different GP width groups.\nThe slope of a power-law fit to the high-energy portion of the CPDs evolves\nfrom -1.7 to -3.2 when going from the shortest to the longest GPs. There are\nbreaks in the CPD power-law fits indicating flattening at low energies with\nindices varying from -1.0 to -1.9 for the short and long GPs respectively. The\nGPs with a stronger peak flux density were found to be of shorter duration. We\ncompare our results with previously published data and discuss the importance\nof these peculiarities in the statistical properties of GPs for the heoretical\nunderstanding of the emission mechanism responsible for GP generation.", "Nonequilibrium transport properties are determined exactly for an\nadiabatically connected single channel quantum wire containing one impurity.\nEmploying the Luttinger liquid model with interaction parameter $g$, for very\nstrong interactions $g\\lapx 0.2$, and sufficiently low temperatures, we find an\nS-shaped current-voltage relation. The unstable branch with negative\ndifferential conductance gives rise to current oscillations and hysteretic\neffects. These non perturbative and non linear features appear only out of\nequilibrium.", "We formulate diagrammatic rules for many-body perturbation theory which uses\nKohn-Sham (KS) Green's functions as basic propagators. The diagram technique\nallows to study the properties of the dynamic nonlocal exchange-correlation\n(xc) kernel $f_{xc}$. We show that the spatial non-locality of $f_{xc}$ is\nstrongly frequency-dependent. In particular, in extended systems the\nnon-locality range diverges at the excitation energies. This divergency is\nrelated to the discontinuity of the xc potential.", "A modified ideal Bose gas model is proposed as an approach for liquid helium\nat the lambda point. The decisive modification of the ideal Bose gas model is\nthe use of phase ordered single particle functions. The entropy due to this\nphase ordering is calculated. Its statistical expectation value yields a\nlogarithmic singularity of the specific heat.", "We present results of a photometric survey whose aim was to derive structural\nand astrophysical parameters for 42 open clusters. While our sample is\ndefinitively not representative of the total open cluster sample in the Galaxy,\nit does cover a wide range of cluster parameters and is uniform enough to allow\nfor simple statistical considerations. BV wide-field CCD photometry was\nobtained for open clusters for which photometric, structural, and dynamical\nevolution parameters were determined. The limiting and core radii were\ndetermined by analyzing radial density profiles. The ages, reddenings, and\ndistances were obtained from the solar metallicity isochrone fitting. The mass\nfunction was used to study the dynamical state of the systems, mass segregation\neffect and to estimate the total mass and number of cluster members. This study\nreports on the first determination of basic parameters for 11 out of 42\nobserved open clusters. The angular sizes for the majority of the observed\nclusters appear to be several times larger than the catalogue data indicate.\nThe core and limiting cluster radii are correlated and the latter parameter is\n3.2 times larger on average. The limiting radius increases with the cluster's\nmass, and both the limiting and core radii decrease in the course of dynamical\nevolution. For dynamically not advanced clusters, the mass function slope is\nsimilar to the universal IMF slope. For more evolved systems, the effect of\nevaporation of low-mass members is clearly visible. The initial mass\nsegregation is present in all the observed young clusters, whereas the\ndynamical mass segregation appears in clusters older than about log(age)=8.\nLow-mass stars are deficient in the cores of clusters older than log(age)=8.5\nand not younger than one relaxation time.", "Most of the works devoted so far to the electronic band structure of\nmultiwall nanotubes have been restricted to the case where the individual\nlayers have the same helicity. By comparison, much less is known on the\nelectronic properties of multiwall nanotubes that mix different helicities.\nThese are interesting systems, however, since they can be composed of both\nmetallic and semiconducting layers. For the present work, tight-binding\ncalculations were undertaken for polychiral two-layer nanotubes such as\n(9,6)@(15,10), (6,6)@(18,2), and others. The recursion technique was used to\ninvestigate how the densities of states of the individual layers are affected\nby the intertube coupling. Constant-current STM images were also calculated for\nthese systems. The result obtained is that the image of a two-wall nanotube is\npretty much the same as the one of the isolated external layer. It is only in\nthe case of monochiral, commensurate structures like (5,5)@(10,10) that\ninterlayer effects can be seen on the STM topography.", "We discuss the findings of a comprehensive imaging and spectroscopic survey\nof the optical emission associated with the supernova remnant 3C 58 (Fesen et\nal. 2007) as they relate to the topic of pre-SN mass loss. Spectroscopically\nmeasured radial velocities of ~450 emission knots within the remnant show two\ndistinct kinematic populations of optical knots: a high-velocity group with\nradial velocities in the range of 700 - 1100 km/s and a lower velocity group\nexhibiting radial expansion velocities below ~250 km/s. We interpret the\nhigh-velocity knots as ejecta from the SN explosion and the low-velocity knots\nas shocked circumstellar material likely resulting from pre-SN mass loss. The\nchemical signatures of the two populations also show marked differences. The\nhigh velocity group includes a substantial number of knots with notably higher\n[N II]/H-alpha ratios not seen in the lower velocity population, suggesting\ngreater nitrogen enrichment in the SN ejecta than in the CSM. These results are\ncompared with evidence for pre-SN mass loss in the Crab Nebula, perhaps the SNR\nmost similar to 3C 58. These SNRs may comprise two case studies of pre-SN mass\nloss in relatively low mass (~8 - 10 solar masses) core-collapse SN\nprogenitors.", "We present a method to construct semi-numerical ``simulations'', which can\nefficiently generate realizations of halo distributions and ionization maps at\nhigh redshifts. Our procedure combines an excursion-set approach with\nfirst-order Lagrangian perturbation theory and operates directly on the linear\ndensity and velocity fields. As such, the achievable dynamic range with our\nalgorithm surpasses the current practical limit of N-body codes by orders of\nmagnitude. This is particularly significant in studies of reionization, where\nthe dynamic range is the principal limiting factor. We test our halo-finding\nand HII bubble-finding algorithms independently against N-body simulations with\nradiative transfer and obtain excellent agreement. We compute the size\ndistributions of ionized and neutral regions in our maps. We find even larger\nionized bubbles than do purely analytic models at the same volume-weighted mean\nhydrogen neutral fraction. We also generate maps and power spectra of 21-cm\nbrightness temperature fluctuations, which for the first time include\ncorrections due to gas bulk velocities. We find that velocities widen the tails\nof the temperature distributions and increase small-scale power, though these\neffects quickly diminish as reionization progresses. We also include some\npreliminary results from a simulation run with the largest dynamic range to\ndate: a 250 Mpc box that resolves halos with masses M >~ 2.2 x10^8 M_sun. We\nshow that accurately modeling the late stages of reionization requires such\nlarge scales. The speed and dynamic range provided by our semi-numerical\napproach will be extremely useful in the modeling of early structure formation\nand reionization.", "We have performed self-consistent 2.5-dimensional nonsteady MHD numerical\nsimulations of jet formation as long as possible, including the dynamics of\naccretion disks. Although the previous nonsteady MHD simulations for\nastrophysical jets revealed that the characteristics of nonsteady jets are\nsimilar to those of steady jets, the calculation time of these simulations is\nvery short compared with the time scale of observed jets. Thus we have\ninvestigated long term evolutions of mass accretion rate, mass outflow rate,\njet velocity, and various energy flux. We found that the ejection of jet is\nquasi-periodic. The period of the ejection is related to the time needed for\nthe initial magnetic filed to be twisted to generate toroidal filed. We compare\nour results with both the steady state theory and previous 2.5-dimensional\nnonsteady MHD simulations.", "We present new multi-wavelength millimeter interferometric observations of\nthe Herbig Ae star HD 163296 obtained with the IRAM/PBI, SMA and VLA arrays\nboth in continuum and in the 12CO, 13CO and C18O emission lines. Gas and dust\nproperties have been obtained comparing the observations with self-consistent\ndisk models for the dust and CO emission. The circumstellar disk is resolved\nboth in the continuum and in CO. We find strong evidence that the circumstellar\nmaterial is in Keplerian rotation around a central star of 2.6 Msun. The disk\ninclination with respect to the line of sight is 46+-4 deg with a position\nangle of 128+-4 deg. The slope of the dust opacity measured between 0.87 and 7\nmm (beta=1) confirms the presence of mm/cm-size grains in the disk midplane.\nThe dust continuum emission is asymmetric and confined inside a radius of 200\nAU while the CO emission extends up to 540 AU. The comparison between dust and\nCO temperature indicates that CO is present only in the disk interior. Finally,\nwe obtain an increasing depletion of CO isotopomers from 12CO to 13CO and C18O.\nWe argue that these results support the idea that the disk of HD 163296 is\nstrongly evolved. In particular, we suggest that there is a strong depletion of\ndust relative to gas outside 200 AU; this may be due to the inward migration of\nlarge bodies that form in the outer disk or to clearing of a large gap in the\ndust distribution by a low mass companion.", "We present spectra for 33 previously unclassified white dwarf systems\nbrighter than V = 17 primarily in the southern hemisphere. Of these new\nsystems, 26 are DA, 4 are DC, 2 are DZ, and 1 is DQ. We suspect three of these\nsystems are unresolved double degenerates. We obtained VRI photometry for these\n33 objects as well as for 23 known white dwarf systems without trigonometric\nparallaxes, also primarily in the southern hemisphere. For the 56 objects, we\nconverted the photometry values to fluxes and fit them to a spectral energy\ndistribution using the spectroscopy to determine which model to use (i.e. pure\nhydrogen, pure helium, or metal-rich helium), resulting in estimates of\neffective temperature and distance. Eight of the new and 12 known systems are\nestimated to be within the NStars and Catalogue of Nearby Stars (CNS) horizons\nof 25 pc, constituting a potential 18% increase in the nearby white dwarf\nsample. Trigonometric parallax determinations are underway via CTIOPI for these\n20 systems.\n  One of the DCs is cool so that it displays absorption in the near infrared.\nUsing the distance determined via trigonometric parallax, we are able to\nconstrain the model-dependent physical parameters and find that this object is\nmost likely a mixed H/He atmosphere white dwarf similar to other cool white\ndwarfs identified in recent years with significant absorption in the infrared\ndue to collision-induced absorptions by molecular hydrogen.", "Intermediate polars (IPs) are cataclysmic variables which contain magnetic\nwhite dwarfs with a rotational period shorter than the binary orbital period.\nEvolutionary theory predicts that IPs with long orbital periods evolve through\nthe 2-3 hour period gap, but it is very uncertain what the properties of the\nresulting objects are. Whilst a relatively large number of long-period IPs are\nknown, very few of these have short orbital periods. We present phase-resolved\nspectroscopy and photometry of SDSS J233325.92+152222.1 and classify it as the\nIP with the shortest known orbital period (83.12 +/- 0.09 min), which contains\na white dwarf with a relatively long spin period (41.66 +/- 0.13 min). We\nestimate the white dwarf's magnetic moment to be mu(WD) \\approx 2 x 10^33 G\ncm^3, which is not only similar to three of the other four confirmed\nshort-period IPs but also to those of many of the long-period IPs. We suggest\nthat long-period IPs conserve their magnetic moment as they evolve towards\nshorter orbital periods. Therefore the dominant population of long-period IPs,\nwhich have white dwarf spin periods roughly ten times shorter than their\norbital periods, will likely end up as short-period IPs like SDSS J2333, with\nspin periods a large fraction of their orbital periods.", "We present a new family of stationary solutions to the cubic nonlinear\nSchroedinger equation with a Jacobian elliptic function potential. In the limit\nof a sinusoidal potential our solutions model a dilute gas Bose-Einstein\ncondensate trapped in a standing light wave. Provided the ratio of the height\nof the variations of the condensate to its DC offset is small enough, both\ntrivial phase and nontrivial phase solutions are shown to be stable. Numerical\nsimulations suggest such stationary states are experimentally observable.", "Summary for the review talk on recent progress in the theoretical studies of\nelectron momentum density distribution at the Sagamore XIII conference (Stare\nJablonki, Poland; September 3-9, 2000).", "We have reexamined data on the possible two dimensional metal-insulator\ntransition at B=0 in Si-MOSFETs using a nonlinear regression method to extract\nall scaling parameters in a single fit. By keeping track of the magnitude of\nerrors in the data we can use the normalized mean square deviation \\chi^2 of\nthe fit as a quantitative measure of how well the data is compatible with\nscaling. We have used this method to study electric field scaling in three\ndifferent samples. We find rather good agreement of the data with scaling in\nindividual fits, i.e. \\chi^2's of about 1, but also rather large variations in\nthe fits depending on how cut-offs are introduced in the data. In particular,\nwe report how fitted parameters vary when we cut away data that are either far\nfrom the critical point or at low excitation power, where temperature effects\npresumably dominate. In this way we find the critical E-field exponent \\beta to\nvary from about 3.2 to 3.9 with considerably smaller statistical error\nestimates in each fit.", "We consider the collective mode spectrum of a normal Fermi gas in a spherical\nharmonic trap. Using a self-consistent random-phase-approximation, we\nsystematically examine the effects of the two-body interactions on the modes of\nvarious symmetries. For weak coupling where the spectrum is shifted very little\naway from the ideal gas case, a sum-rule approach is shown to work well.\n  For stronger coupling, the interplay between the single particle and the\ncollective excitations causes effects such as mode splitting and Landau\ndamping. A finite low frequency response present at stronger coupling is\npredicted for the quadrupole mode. Finally, we briefly discuss the effect of a\nfinite temperature on the spectrum and the excitation of higher collective\nmodes.", "Calculations of Raman scattering intensities in spin 1/2 square-lattice\nHeisenberg model, using the Fleury-Loudon-Elliott theory, have so far been\nunable to describe the broad line shape and asymmetry of the two magnon peak\nfound experimentally in the cuprate materials. Even more notably, the\npolarization selection rules are violated with respect to the\nFleury-Loudon-Elliott theory. There is comparable scattering in $B_{1g}$ and\n$A_{1g}$ geometries, whereas the theory would predict scattering in only\n$B_{1g}$ geometry. We review various suggestions for this discrepency and\nsuggest that at least part of the problem can be addressed by modifying the\neffective Raman Hamiltonian, allowing for two-magnon states with arbitrary\ntotal momentum. Such an approach based on the Sawatzsky-Lorenzana theory of\noptical absorption assumes an important role of phonons as momentum sinks. It\nleaves the low energy physics of the Heisenberg model unchanged but\nsubstantially alters the Raman line-shape and selection rules, bringing the\nresults closer to experiments.", "In [1] it was proposed, that the nearest-neighbor distribution $P(s)$ of the\nspectrum of the Bohr-Mottelson model is similar to the semi-Poisson\ndistribution. We show however, that $P(s)$ of this model differs considerably\nin many aspects from semi-Poisson. In addition we give an asymptotic formula\nfor $P(s)$ as $s \\to 0$, which gives $P'(0) = \\pi\\sqrt{3}/2$ for the slope at\n$s=0$. This is different not only from the GOE case but also from the\nsemi-Poisson prediction that leads to $P'(0) = 4$", "We investigate colour selection techniques for high redshift galaxies in the\nUKIDSS Ultra Deep Survey Early Data Release (UDS EDR). Combined with very deep\nSubaru optical photometry, the depth (K_AB = 22.5) and area (0.62 deg^2) of the\nUDS EDR allows us to investigate optical/near-IR selection using a large sample\nof over 30,000 objects. By using the B-z, z-K colour-colour diagram (the BzK\ntechnique) we identify over 7500 candidate galaxies at z > 1.4, which can be\nfurther separated into passive and starforming systems (pBzK and sBzK\nrespectively). Our unique sample allows us to identify a new feature not\npreviously seen in BzK diagrams, consistent with the passively evolving track\nof early type galaxies at z < 1.4. We also compare the BzK technique with the\nR-K colour selection of Extremely Red Objects (EROs) and the J-K selection of\nDistant Red Galaxies (DRGs), and quantify the overlap between these\npopulations. We find that the majority of DRGs, at these relatively bright\nmagnitudes are also EROs. Since previous studies have found that DRGs at these\nmagnitudes have redshifts of z ~ 1 we determine that these DRG/ERO galaxies\nhave SEDs consistent with being dusty star-forming galaxies or AGN at z < 2.\nFinally we observe a flattening in the number counts of pBzK galaxies, similar\nto other studies, which may indicate that we are sampling the luminosity\nfunction of passive z > 1 galaxies over a narrow redshift range.", "We show that the jet structure of gamma-ray bursts (GRBs) can be investigated\nwith the tail emission of the prompt GRB. The tail emission which we consider\nis identified as a steep-decay component of the early X-ray afterglow observed\nby the X-ray Telescope onboard Swift. Using a Monte Carlo method, we derive,\nfor the first time, the distribution of the decay index of the GRB tail\nemission for various jet models. The new definitions of the zero of time and\nthe time interval of a fitting region are proposed. These definitions for\nfitting the light curve lead us an unique definition of the decay index, which\nis useful to investigate the structure of the GRB jet. We find that if the GRB\njet has a core-envelope structure, the predicted distribution of the decay\nindex of the tail has a wide scatter and has multiple peaks, which cannot be\nseen for the case of the uniform and the Gaussian jet. Therefore, the decay\nindex distribution tells us the information on the jet structure. Especially,\nif we observe events whose decay index is less than about 2, both the uniform\nand the Gaussian jet models will be disfavored according to our simulation\nstudy.", "It has been argued in a recent paper by R. Joynt (R. Joynt, Science 284, p\n777 (1999)) that in the case of poorly conducting solids the photoemission\nspectrum close to the Fermi Energy may be strongly influenced by extrinsic loss\nprocesses similar to those occurring in High Resolution Electron Energy Loss\nSpectroscopy (HR-EELS), thereby obscuring information concerning the density of\nstates or one electron Green's function sought for. In this paper we present a\nnumber of arguments, both theoretical and experimental, that demonstrate that\nenergy loss processes occurring once the electron is outside the solid,\ncontribute only weakly to the spectrum and can in most cases be either\nneglected or treated as a weak structureless background.", "We study the statistical properties of two hard spheres in a two dimensional\nrectangular box. In this system, the relation like Van der Waals equation loop\nis obtained between the width of the box and the pressure working on side\nwalls. The auto-correlation function of each particle's position is calculated\nnumerically. By this calculation near the critical width, the time at which the\ncorrelation become zero gets longer according to the increase of the height of\nthe box. Moreover, fast and slow relaxation processes like $\\alpha$ and $\\beta$\nrelaxations observed in supper cooled liquid are observed when the height of\nthe box is sufficiently large. These relaxation processes are discussed with\nthe probability distribution of relative position of two particles.", "Common envelopes form in dynamical time scale mass exchange, when the\nenvelope of a donor star engulfs a much denser companion, and the core of the\ndonor plus the dense companion star spiral inward through this dissipative\nenvelope. As conceived by Paczynski and Ostriker, this process must be\nresponsible for the creation of short-period binaries with degenerate\ncomponents, and, indeed, it has proven capable of accounting for short-period\nbinaries containing one white dwarf component. However, attempts to reconstruct\nthe evolutionary histories of close double white dwarfs have proven more\nproblematic, and point to the need for enhanced systemic mass loss, either\nduring the close of the first, slow episode of mass transfer that produced the\nfirst white dwarf, or during the detached phase preceding the final, common\nenvelope episode. The survival of long-period interacting binaries with massive\nwhite dwarfs, such as the recurrent novae T CrB and RS Oph, also presents\ninterpretative difficulties for simple energetic treatments of common envelope\nevolution. Their existence implies that major terms are missing from usual\nformulations of the energy budget for common envelope evolution. The most\nplausible missing energy term is the energy released by recombination in the\ncommon envelope, and, indeed, a simple reformulation the energy budget\nexplicitly including recombination resolves this issue.", "The role of the equation of state for a perfectly conducting, relativistic\nmagnetized fluid is the main subject of this work. The ideal constant\n$\\Gamma$-law equation of state, commonly adopted in a wide range of\nastrophysical applications, is compared with a more realistic equation of state\nthat better approximates the single-specie relativistic gas. The paper focus on\nthree different topics. First, the influence of a more realistic equation of\nstate on the propagation of fast magneto-sonic shocks is investigated. This\ncalls into question the validity of the constant $\\Gamma$-law equation of state\nin problems where the temperature of the gas substantially changes across\nhydromagnetic waves. Second, we present a new inversion scheme to recover\nprimitive variables (such as rest-mass density and pressure) from conservative\nones that allows for a general equation of state and avoids catastrophic\nnumerical cancellations in the non-relativistic and ultrarelativistic limits.\nFinally, selected numerical tests of astrophysical relevance (including\nmagnetized accretion flows around Kerr black holes) are compared using\ndifferent equations of state. Our main conclusion is that the choice of a\nrealistic equation of state can considerably bear upon the solution when\ntransitions from cold to hot gas (or viceversa) are present. Under these\ncircumstances, a polytropic equation of state can significantly endanger the\nsolution.", "In the decreasing intrinsic redshift (DIR) model galaxies are assumed to be\nborn as compact objects that have been ejected with large intrinsic redshift\ncomponents, z_(i), out of the nuclei of mature AGN galaxies. As young AGN\n(quasars) they are initially several magnitudes sub-luminous to mature galaxies\nbut their luminosity gradually increases over 10^8 yrs, as z_(i) decreases and\nthey evolve into mature AGN (Seyferts and radio galaxies). Evidence presented\nhere that low- and intermediate-redshift AGN are unquestionably sub-luminous to\nradio galaxies is then strong support for this model and makes it likely that\nthe high-redshift AGN (quasars) are also sub-luminous, having simply been\npushed above the radio galaxies on a logz-m_(v) plot by the presence of a large\nintrinsic component in their redshifts. An increase in luminosity below z =\n0.06 is also seen. It is associated in the DIR model with an increase in\nluminosity as the sources mature but, if real, is difficult to interpret in the\ncosmological redshift (CR) model since at this low redshift it is unlikely to\nbe associated with a higher star formation rate or an increase in the material\nused to build galaxies. Whether it might be possible in the CR model to explain\nthese results by selection effects is also examined.", "OH masers at 1720 MHz have proven to be excellent indicators of interactions\nbetween supernova remnants and molecular clouds. Recent calculations suggest\nthat the 6049 MHz OH maser line is excited for higher column densities than for\nthe 1720 MHz line. It is therefore a potentially valuable indicator of\nremnant-cloud interaction.\n  We present preliminary results of a survey using the Parkes Methanol\nMultibeam receiver for 6049 MHz and 6035/6030 MHz OH masers towards 36\nsupernova remnants and 4 fields in the Large and Small Magellanic Clouds. While\nno 6049 MHz masers have been found, three new sites of 6035 and 6030 MHz OH\nmaser emission have been discovered in star-forming regions.", "We present transport and structural data from epitaxial (100) and (111) Au/Fe\nmultilayers grown by molecular beam epitaxy. From their analysis, we conclude\nthat an electron channelling mechanism, due to strong specular reflection of\nthe minority spin carrier at the Au/Fe interfaces, is responsible for the high\nconductivity in the (100) multilayers.", "The astrometric signature imposed by a planet on its primary increases\nsubstantially towards longer periods (proportinal to P^2/3), so that\nlong-period planets can be more easily detected, in principle. For example, a\none Solar-mass (M_Sun) star would be pulled by roughly 1 mas by a one\nJupiter-mass (M_J) planet with a period of one-hundred years at a distance of\n20 pc. Such position accuracies can now be obtained with both ground-based and\nspace-based telescopes. The difficulty was that it often takes many decades\nbefore a detectable position shift will occur. However, by the time the next\ngeneration of astrometric missions such as SIM will be taking data, several\ndecades will have past since the first astrometric mission, HIPPARCOS. Here we\npropose to use a new astrometric method that employs a future, highly accurate\nSIM Quick-Look survey and HIPPARCOS data taken twenty years prior. Using\nposition errors for SIM of 4 muas, this method enables the detection and\ncharacterization of Solar-system analogs (SOSAs) with periods up to 240 (500)\nyears for 1 (10) M_J companions. Because many tens of thousands nearby stars\ncan be surveyed this way for a modest expenditure of SIM time and SOSAs may be\nquite abundant, we expect to find many hundreds of extra-solar planets with\nlong-period orbits. Such a data set would nicely complement the short-period\nsystems found by the radial-velocity method. Brown dwarfs and low-mass stellar\ncompanions can be found and characterized if their periods are shorter than\nabout 500 years. This data set will provide invaluable constraints on models of\nplanet formation, as well as a database for systems where the location of the\ngiant planets allow for the formation of low-mass planets in the habitable\nzone. [Abridged]", "We report results from a 30 ks observation of Cygnus X-1 with the High Energy\nTransmission Grating Spectrometer (HETGS) on board the {\\em Chandra X-ray\nObservatory}. Numerous absorption lines were detected in the HETGS spectrum.\nThe lines are associated with highly ionized Ne, Na, Mg, Al, Si, S, and Fe,\nsome of which have been seen in earlier HETGS observations. Surprisingly,\nhowever, we discovered dramatic variability of the lines over the duration of\nthe present observation. For instance, the flux of the Ne X line at 12.14 \\AA\\\nwas about $5 \\times 10^{-3}$ photons cm$^{-2}$ s$^{-1}$ in the early part of\nthe observation but became subsequently undetectable, with a 99% upper limit of\n$0.06 \\times 10^{-3}$ photons cm$^{-2}$ s$^{-1}$ on the flux of the line. This\nimplies that the line weakened by nearly two orders of magnitude on a timescale\nof hours. The overall X-ray flux of the source did also vary during the\nobservation but only by 20--30%. For Cyg X-1, the absorption lines are\ngenerally attributed to the absorption of X-rays by ionized stellar wind in the\nbinary system. Therefore, they may provide valuable diagnostics on the physical\ncondition of the wind. We discuss the implications of the results.", "Charged skyrmions or spin-textures in the quantum Hall ferromagnet at filling\nfactor nu=1 are reinvestigated using the Hartree-Fock method in the lowest\nLandau level approximation. It is shown that the single Slater determinant with\nthe minimum energy in the unit charge sector is always of the hedgehog form. It\nis observed that the magnetization vector's length deviates locally from unity,\ni.e. a bag is formed which accommodates the excess charge. In terms of a\ngradient expansion for extended spin-textures a novel O(3) type of effective\naction is presented, which takes bag formation into account.", "In an interesting new experiment the electronic structure of a magnetic atom\nadsorbed on the surface of Cu(111), observed by STM, was projected into a\nremote location on the same surface. The purpose of the present paper is to\ninterpret this experiment with a model Hamiltonian, using ellipses of the size\nof the experimental ones, containing about 2300 atoms. The charge distribution\nfor the different wavefunctions is analyzed, in particular, for those with\nenergy close to the Fermi energy of copper Ef. Some of them show two symmetric\nmaxima located on the principal axis of the ellipse but not necessarily at the\nfoci. If a Co atom is adsorbed at the site where the wavefunction with energy\n$E_F$ has a maximum and the interaction is small, the main effect of the\nadsorbed atom will be to split this particular wavefunction in two. The total\ncharge density will remain the same but the local density of states will\npresent a dip at Ef at any site where the charge density is large enough. We\nrelate the presence of this dip to the observation of quantum mirages. Our\ninterpretation suggests that other sites, apart from the foci of the ellipses,\ncan be used for projecting atomic images and also indicates the conditions for\nother non magnetic adsorbates to produce mirages.", "We report on the atom optical manipulation of an atom laser beam. Reflection,\nfocusing and its storage in a resonator are demonstrated. Precise and versatile\nmechanical control over an atom laser beam propagating in an inhomogeneous\nmagnetic field is achieved by optically inducing spin-flips between atomic\nground states with different magnetic moment. The magnetic force acting on the\natoms can thereby be effectively switched on and off. The surface of the atom\noptical element is determined by the resonance condition for the spin-flip in\nthe inhomogeneous magnetic field. A mirror reflectivity of more than 98% is\nmeasured.", "Ferromagnetism was recently observed at unexpectedly high temperatures in\nLa-doped CaB_6. The starting point of all theoretical proposals to explain this\nobservation is a semimetallic electronic structure calculated for CaB_6 within\nthe local density approximation. Here we report the results of parameter-free\nquasiparticle calculations of the single-particle excitation spectrum which\nshow that CaB_6 is not a semimetal but a semiconductor with a band gap of 0.8\neV. Magnetism in La_xCa_{1-x}B_6 occurs just on the metallic side of a Mott\ntransition in the La-induced impurity band.", "The Seyfert 2 galaxies NGC 2992 and NGC 3081 have been observed by INTEGRAL\nand Swift. We report about the results and the comparison of the spectrum above\n10 keV based on INTEGRAL IBIS/ISGRI, Swift/BAT, and BeppoSAX/PDS. A spectrum\ncan be extracted in the X-ray energy band ranging from 1 keV up to 200 keV.\nAlthough NGC 2992 shows a complex spectrum below 10 keV, the hard tail observed\nby various missions exhibits a slope with photon index = 2, independent on the\nflux level during the observation. No cut-off is detectable up to the detection\nlimit around 200 keV. In addition, NGC 3081 is detected in the INTEGRAL and\nSwift observation and also shows an unbroken Gamma = 1.8 spectrum up to 150\nkeV. These two Seyfert galaxies give further evidence that a high-energy\ncut-off in the hard X-ray spectra is often located at energies E_C >> 100 keV.\nIn NGC 2992 a constant spectral shape is observed over a hard X-ray luminosity\nvariation by a factor of 11. This might indicate that the physical conditions\nof the emitting hot plasma are constant, while the amount of plasma varies, due\nto long-term flaring activity.", "We show that effective interactions mediated by disorder between two directed\npolymers can be modelled as the crosscorrelation of noises in the\nKardar-Parisi-Zhang (KPZ) equations satisfied by the respective free energies\nof these polymers. When there are two polymers, disorder introduces attractive\ninteractions between them. We analyze the phase diagram in details and show\nthat these interactions lead to new phases in the phase diagram. We show that,\neven in dimension $d=1$, the two directed polymers see the attraction only if\nthe strength of the disorder potential exceeds a threshold value. We extend our\ncalculations to show that if there are $m$ polymers in the system then $m$-body\ninteractions are generated in the disorder averaged effective free energy.", "The physical properties of almost any kind of astronomical object can be\nderived by fitting synthetic spectra or photometry extracted from theoretical\nmodels to observational data. This process usually involves working with\nmultiwavelength data, which is one of the cornerstones of the VO philosophy.\n  From this kind of studies, when combining with theoretical isochrones one can\neven estimate ages. We present here the results obtained from a code designed\nto perform chi^2 tests to both spectroscopic models (or the associated\nsynthetic photometry) and combinations of blackbodies (including modified\nblackbodies). Some steps in this process can already be done in a VO\nenvironment, and the rest are in the process of development. We must note that\nthis kind of studies in star forming regions, clusters, etc. produce a huge\namount of data, very tedious to analyze using the traditional methodology. This\nmake them excellent examples where to apply the VO capabilities.", "GREGOR is a new open solar telescope with an aperture of 1.5m. It replaces\nthe former 45-cm Gregory Coude telescope on the Canary island Tenerife. The\noptical concept is that of a double Gregory system. The main and the elliptical\nmirrors are made from a silicon-carbide material with high thermal\nconductivity. This is important to keep the mirrors on the ambient temperature\navoiding local turbulence. GREGOR will be equipped with an adaptive optics\nsystem. The new telescope will be ready for operation in 2008. Post-focus\ninstruments in the first stage will be a spectrograph for polarimetry in the\nnear infrared and a 2-dimensional spectrometer based on Fabry-Perot\ninterferometers for the visible.", "By considering the enlarged thermal system including the heat bath, it is\nshown that this system has supersymmetry which is not broken at finite\ntemperature. The super algebra is constructed and the Hamiltonian is expressed\nas the anti-commutator of two kinds of super charges. With this Hamiltonian and\nthe thermal vacuum $\\mid 0(\\beta)>$, this supersymmetry is found to be\npreserved.", "The analysis of databases of photographic images of the Sun (obtained in\nregion of soft x-ray) by means of a method of multilevel dynamical contrasting,\nhas shown presence of skeletal structures of the Sun as outside (chromo-sphere\nflashes and powerful coronal mass ejections) and on the Sun (structures in its\natmosphere, protuberances and of solar a stains). Moreover the structures which\nradius of rotation is less than radius of a solar disk on breadth of their\nobservation have been revealed. On the basis of the obtained results of this\nanalysis, the author puts forward a hypothesis about an opportunity of\nexistence of some filamentary matter as inside, so outside of the Sun.", "We report the discovery of a new white dwarf/M dwarf binary, HS1857+5144,\nidentified in the Hamburg Quasar Survey (HQS). Time-resolved optical\nspectroscopy and photometry were carried out to determine the properties of\nthis new cataclysmic variable progenitor pre-CV). The light curves of\nHS1857+5144 display a sinusoidal variation with a period of Porb=383.52 min and\npeak-to-peak amplitudes of 0.7 mag and 1.1 mag in the B-band and R-band,\nrespectively. The large amplitude of the brightness variation results from a\nreflection effect on the heated inner hemisphere of the companion star,\nsuggesting a very high temperature of the white dwarf. Our radial velocity\nstudy confirms the photometric period as the orbital period of the system. A\nmodel atmosphere fit to the spectrum of the white dwarf obtained at minimum\nlight provides limits to its mass and temperature of Mwd=~0.6-1.0 Msun and\nTwd=~70000-100000 K, respectively. The detection of HeII 4686 absorption\nclassifies the primary star of HS1857+5144 as a DAO white dwarf. Combining the\nresults from our spectroscopy and photometry, we estimate the mass of the\ncompanion star and the binary inclination to be Msec=~0.15-0.30 Msun and\ni=~45-55 deg, respectively. We classify HS1857+5144 as one of the youngest\npre-CV known to date. The cooling age of the white dwarf suggests that the\npresent system has just emerged from a common envelope phase ~10^5 yr ago.\nHS1857+5144 will start mass transfer within or below the 2-3h period gap.", "Recent applications have proved that the Surface Brightness Fluctuations\n(SBF) technique is a reliable distance indicator in a wide range of distances,\nand a promising tool to analyze the physical and chemical properties of\nunresolved stellar systems, in terms of their metallicity and age. We present\nthe preliminary results of a project aimed at studying the evolutionary\nproperties and distance of the stellar populations in external galaxies based\non the SBF method.\n  On the observational side, we have succeeded in detecting I-band SBF\ngradients in six bright ellipticals imaged with the ACS, for these same objects\nwe are now presenting also B-band SBF data. These B-band data are the first\nfluctuations magnitude measurements for galaxies beyond 10 Mpc.\n  To analyze the properties of stellar populations from the data, accurate SBF\nmodels are essential. As a part of this project, we have evaluated SBF\nmagnitudes from Simple Stellar Population (SSP) models specifically optimized\nfor the purpose. A wide range of chemical compositions and ages, as well as\ndifferent choices of the photometric system have been investigated. All models\nare available at the Teramo-Stellar Populations Tools web site:\nwww.oa-teramo.inaf.it/SPoT.", "We present observations of pure rotational molecular hydrogen emission from\nthe Herbig Ae star, AB Aurigae. Our observations were made using the Texas\nEchelon Cross Echelle Spectrograph (TEXES) at the NASA Infrared Telescope\nFacility and the Gemini North Observatory. We searched for H2 emission in the\nS(1), S(2), and S(4) lines at high spectral resolution and detected all three.\nBy fitting a simple model for the emission in the three transitions, we derive\nT = 670 +/- 40 K and M = 0.52 +/- 0.15 earth masses for the emitting gas. Based\non the 8.5 km/s FWHM of the S(2) line, assuming the emission comes from the\ncircumstellar disk, and with an inclination estimate of the AB Aur system taken\nfrom the literature, we place the location for the emission near 18 AU.\nComparison of our derived temperature to a disk structure model suggests that\nUV and X-ray heating are important in heating the disk atmosphere.", "We consider the ordering kinetics in a strongly non-equilibrium state of a\n(weakly) interacting Bose gas, characterized, on one hand, by large occupation\nnumbers, and, on the other hand, by the absence of long-range order. Up to\nhigher-order corrections in inverse occupation numbers, the evolution is\ndescribed by non-linear Schrodinger equation with a turbulent initial state.\nThe ordering process is rather rich and involves a number of qualitatively\ndifferent regimes that take place in different regions of energy space.\nSpecially addressed is the case of evolution in an external potential.", "We study the dynamics of two interacting Bose-Einstein condensates, by\nnumerically solving two coupled Gross-Pitaevskii equations at zero temperature.\nWe consider the case of a sudden transfer of atoms between two trapped states\nwith different magnetic moments: the two condensates are initially created with\nthe same density profile, but are trapped into different magnetic potentials,\nwhose minima are vertically displaced by a distance much larger than the\ninitial size of both condensates. Then the two condensates begin to perform\ncollective oscillations, undergoing a complex evolution, characterized by\ncollisions between the two condensates. We investigate the effects of their\nmutual interaction on the center-of-mass oscillations and on the time evolution\nof the aspect ratios. Our theoretical analysis provides a useful insight into\nthe recent experimental observations by Maddaloni et al., cond-mat/0003402.", "This paper provides a way to classify vocal disorders for clinical\napplications. This goal is achieved by means of geometric signal separation in\na feature space. Typical quantities from chaos theory (like entropy,\ncorrelation dimension and first lyapunov exponent) and some conventional ones\n(like autocorrelation and spectral factor) are analysed and evaluated, in order\nto provide entries for the feature vectors. A way of quantifying the amount of\ndisorder is proposed by means of an healthy index that measures the distance of\na voice sample from the centre of mass of both healthy and sick clusters in the\nfeature space. A successful application of the geometrical signal separation is\nreported, concerning distinction between normal and disordered phonation.", "Light propagation in a photonic crystal infiltrated with polarizable\nmolecules is considered. We demonstrate that the interplay between the spatial\ndispersion caused by Bragg diffraction and polaritonic frequency dispersion\ngives rise to novel propagating excitations, or braggoritons, with intragap\nfrequencies. We derive the braggoriton dispersion relation and show that it is\ngoverned by two parameters, namely, the strength of light-matter interaction\nand detuning between the Bragg frequency and that of the infiltrated molecules.\nWe also study defect-induced states when the photonic band gap is divided into\ntwo subgaps by the braggoritonic branches and find that each defect creates two\nintragap localized states inside each subgap.", "Water absorption is identified in the atmosphere of HD209458b by comparing\nmodels for the planet's transmitted spectrum to recent, multi-wavelength,\neclipse-depth measurements (from 0.3 to 1 microns) published by Knutson et al.\n(2007). A cloud-free model which includes solar abundances, rainout of\ncondensates, and photoionization of sodium and potassium is in good agreement\nwith the entire set of eclipse-depth measurements from the ultraviolet to\nnear-infrared. Constraints are placed on condensate removal by gravitational\nsettling, the bulk metallicity, and the redistribution of absorbed stellar\nflux. Comparisons are also made to the Charbonneau et al. (2002) sodium\nmeasurements.", "At least four high-frequency quasiperiodic oscillations (QPOs) at frequencies\n41Hz, 67Hz, 113Hz, and 167Hz were reported in a binary system GRS 1915+105\nhosting near-extreme Kerr black hole with a dimensionless spin a>0.98. We use\nthe idea of oscillations induced by the hump of the orbital velocity profile\n(related to locally non-rotating frames - LNRF) in discs orbiting near-extreme\nKerr black holes, which are characterized by a \"humpy frequency\" f_h, that\ncould excite the radial and vertical epicyclic oscillations with frequencies\nf_r, f_v. Due to non-linear resonant phenomena the combinational frequencies\nare allowed as well. Assuming mass M=14.8M_sun and spin a=0.9998 for the GRS\n1915+105 Kerr black hole, the model predicts frequencies f_h=41Hz, f_r=67Hz,\n(f_h+f_r)=108Hz, (f_v-f_r)=170Hz corresponding quite well to the observed ones.\nFor black-hole parameters being in good agreement with those given\nobservationally, the forced resonant phenomena in non-linear oscillations,\nexcited by the \"hump-induced\" oscillations in a Keplerian disc, can explain\nhigh-frequency QPOs in GRS 1915+105 within the range of observational errors.", "Quantum degeneracy modifies light scattering and spontaneous emission. For\nfermions, Pauli blocking leads to a suppression of both processes. In contrast,\nin a weakly interacting Bose-Einstein condensate, we find spontaneous emission\nto be enhanced, while light scattering is suppressed. This difference is\nattributed to many-body effects and quantum interference in a Bose-Einstein\ncondensate.", "We consider the finite-size scaling of equilibrium droplet shapes for fluid\nadsorption (at bulk two-phase co-existence) on heterogeneous substrates and\nalso in wedge geometries in which only a finite domain $\\Lambda_{A}$ of the\nsubstrate is completely wet. For three-dimensional systems with short-ranged\nforces we use renormalization group ideas to establish that both the shape of\nthe droplet height and the height-height correlations can be understood from\nthe conformal invariance of an appropriate operator. This allows us to predict\nthe explicit scaling form of the droplet height for a number of different\ndomain shapes. For systems with long-ranged forces, conformal invariance is not\nobeyed but the droplet shape is still shown to exhibit strong scaling\nbehaviour. We argue that droplet formation in heterogeneous wedge geometries\nalso shows a number of different scaling regimes depending on the range of the\nforces. The conformal invariance of the wedge droplet shape for short-ranged\nforces is shown explicitly.", "The magnetic field in an accretion disk is estimated assuming that all of the\nangular momentum within prescribed accretion disk radii is removed by a jet.\nThe magnetic field estimated at the base of the jet is extrapolated to the\nblazar emission region using a model for a relativistic axisymmetric jet\ncombined with some simplifying assumptions based on the relativistic nature of\nthe flow. The extrapolated magnetic field is compared with estimates based upon\nthe synchrotron and inverse Compton emission from three blazars, MKN 501, MKN\n421 and PKS 2155-304. The magnetic fields evaluated from pure synchrotron self-\nCompton models are inconsistent with the magnetic fields extrapolated in this\nway. However, in two cases inverse Compton models in which a substantial part\nof the soft photon field is generated locally agree well, mainly because these\nmodels imply magnetic field strengths which are closer to being consistent with\nPoynting flux dominated jets. This comparison is based on estimating the mass\naccretion rate from the jet energy flux. Further comparisons along these lines\nwill be facilitated by independent estimates of the mass accretion rate in\nblazars and by more detailed models for jet propagation near the black hole.", "Diskoseismology, the theoretical study of small adiabatic hydrodynamical\nglobal perturbations of geometrically thin, optically thick accretion disks\naround black holes (and other compact objects), is a potentially powerful probe\nof the gravitational field. For instance, the frequencies of the normal mode\noscillations can be used to determine the elusive angular momentum parameter of\nthe black hole. The general formalism developed by diskoseismologists for\nrelativistic systems can be readily applied to the Newtonian case of\ncataclysmic variables (CVs). Some of these systems (e.g., the dwarf nova SS\nCygni) show rapid oscillations in the UV with periods of tens of seconds and\nhigh coherence. In this paper, we assess the possibility that these dwarf nova\noscillations (DNOs) are diskoseismic modes. Besides its importance in\ninvestigating the physical origin of DNOs, the present work could help us to\nanswer the following question. To what extent are the similarities in the\noscillation phenomenology of CVs and X-ray binaries (XRBs) indicative of a\ncommon physical mechanism?", "We present a Random-Phase-Approximation formalism for the collective spectrum\nof two hyperfine species of dilute 40K atoms, magnetically trapped at zero\ntemperature and subjected to a repulsive s-wave interaction between atoms with\ndifferent spin projections. We examine the density-like and the spin-like\noscillation spectra, as well as the transition density profiles created by\nexternal multipolar fields. The zero sound spectrum is always fragmented and\nthe density and spin channels become clearly distinguishable if the trapping\npotentials acting on the species are identical. Although this distinction is\nlost when these confining fields are different, at selected excitation\nfrequencies the transition densities may display the signature of the channel.", "The large-scale Galactic interstellar radiation field (ISRF) is the result of\nstellar emission and dust re-processing of starlight. Where the energy density\nof the ISRF is high (e.g., the Galactic Centre), the dominant gamma-ray\nemission in individual supernova remnants (SNRs), such as G0.9+0.1, may come\nfrom inverse Compton (IC) scattering of the ISRF. Several models of the ISRF\nexist. The most recent one, which has been calculated by us, predicts a\nsignificantly higher ISRF than the well-used model of Mathis, Mezger, and\nPanagia. However,comparison with data is limited to local observations. Based\non our current estimate of the ISRF we predict the gamma-ray emission in the\nSNRs G0.9+0.1 and RXJ1713, and pair-production absorption features above 20 TeV\nin the spectra of G0.9+0.1, J1713-381, and J1634-472. We discuss how GLAST,\nalong with current and future very high energy instruments, may be able to\nprovide upper bounds on the large-scale ISRF.", "We present the first X-ray detection of the very young pulsar PSR J1357-6429\n(characteristic age of 7.3 kyr) using data from the XMM-Newton and Chandra\nsatellites. We find that the spectrum is well described by a power-law plus\nblackbody model, with photon index Gamma=1.4 and blackbody temperature kT=160\neV. For the estimated distance of 2.5 kpc, this corresponds to a 2-10 keV\nluminosity of about 1.2E+32 erg/s, thus the fraction of the spin-down energy\nchanneled by PSR J1357-6429 into X-ray emission is one of the lowest observed.\nThe Chandra data confirm the positional coincidence with the radio pulsar and\nallow to set an upper limit of 3E+31 erg/s on the 2-10 keV luminosity of a\ncompact pulsar wind nebula. We do not detect any pulsed emission from the\nsource and determine an upper limit of 30% for the modulation amplitude of the\nX-ray emission at the radio frequency of the pulsar.", "Dynamic xx spin pair correlation functions for the isotropic spin-1/2 XY\nchain are calculated numerically for long open chains in the presence of a\ntransverse magnetic field at finite temperature. As an application we discuss\nthe temperature dependence of the spin-spin relaxation time in PrCl_3.", "We use the Density Matrix Renormalization Group technique to compute\ncorrelation functions of the Z_3-chiral Potts quantum chain in the massive\nregimes. Chains of up to 70 sites are used and a clear oscillatory behavior is\nfound. We also check the relation between the density matrix spectrum and the\nCorner Transfer Matrix spectrum pointed out by Nishino and Okunishi, using\nBaxter's low-temperature formulae for the chiral Potts Corner Transfer Matrix\neigenvalues. We find very good agreement.", "We present the results of SiO line observations of a sample of known SiO\nmaser sources covering a wide dust-temperature range. The aim of the present\nresearch is to investigate the causes of the correlation between infrared\ncolors and SiO maser intensity ratios among different transition lines. We\nobserved in total 75 SiO maser sources with the Nobeyama 45m telescope\nquasi-simultaneously in the SiO J=1-0 v=0, 1, 2, 3, 4 and J=2-1 v=1, 2 lines.\nWe also observed the sample in the 29SiO J=1-0 v=0 and J=2-1 v=0, and 30SiO\nJ=1-0 v=0 lines, and the H2O 6(1,6)-5(2,3) line. As reported in previous\npapers, we confirmed that the intensity ratios of the SiO J=1-0 v=2 to v=1\nlines clearly correlate with infrared colors. In addition, we found possible\ncorrelation between infrared colors and the intensity ratios of the SiO J=1-0\nv=3 to v=1&2 lines.", "Consequences of different discretizations of the two-dimensional Dirac\noperator on low energy properties (e.g., the number of nodes) and their\nrelations to gauge properties are discussed. Breaking of the gauge invariance\nwas suggested in a recent work by M. Bocquet, D. Serban, and M.R. Zirnbauer\n[cond-mat/9910480] in order to destroy an intermediate metallic phase of\nlattice Dirac fermions with random mass. It is explained that such a procedure\nis inconsistent with the underlying lattice physics. Previous results point out\nthat the logarithmic growth of the slope of the average density of states with\nthe system size, obtained in the field-theoretical calculation of M. Bocquet et\nal., could be a precursor for the appearence of an intermediate metallic phase.", "We present results of an attempt to include more detailed gas physics\nmotivated from hydrodynamical simulations within semi-analytic models (SAM) of\ngalaxy formation, focusing on the role that environmental effects play. The\nmain difference to previous SAMs is that we include 'gravitational' heating of\nthe intra-cluster medium (ICM) by the net surplus of gravitational potential\nenergy released from gas that has been stripped from infalling satellites.\nGravitational heating appears to be an efficient heating source able to prevent\ncooling in environments corresponding to dark matter halos more massive than\n$\\sim 10^{13} $M$_{\\odot}$. The energy release by gravitational heating can\nmatch that by AGN-feedback in massive galaxies and can exceed it in the most\nmassive ones. However, there is a fundamental difference in the way the two\nprocesses operate. Gravitational heating becomes important at late times, when\nthe peak activity of AGNs is already over, and it is very mass dependent. This\nmass dependency and time behaviour gives the right trend to recover down-sizing\nin the star-formation rate of massive galaxies. Abridged...", "Carbon nanotube junctions are predicted to exhibit negative differential\nresistance, with very high peak-to-valley current ratios even at room\ntemperature. We treat both nanotube p-n junctions and undoped\nmetal-nanotube-metal junctions, calculating quantum transport through the\nself-consistent potential within a tight-binding approximation. The undoped\njunctions in particular may be suitable for device integration.", "The performance of many-body perturbation theory for calculating ground-state\nproperties is investigated. We present fully numerical results for the electron\ngas in three and two dimensions in the framework of the GW approximation. The\noverall agreement with very accurate Monte Carlo data is excellent, even for\nthose ranges of densities for which the GW approach is often supposed to be\nunsuitable. The latter seems to be due to the fulfilment of general\nconservation rules. These results open further prospects for accurate\ncalculations of ground-state properties circumventing the limitations of\nstandard density functional theory.", "We present the first reliable calculation of the collective mode structure of\na strongly coupled electronic bilayer. The calculation is based on a classical\nmodel through the $3^{rd}$ frequency-moment-sum-rule preserving Quasi Localized\nCharge Approximation, using the recently calculated Hypernetted Chain pair\ncorrelation functions. The spectrum shows an energy gap at $k=0$ and the\nabsence of a previously conjectured dynamical instability.", "We study the possibility that the mutual interactions between Jupiter and\nSaturn prevented Type II migration from driving these planets much closer to\nthe Sun. Our work extends previous results by Masset and Snellgrove (2001), by\nexploring a wider set of initial conditions and disk parameters, and by using a\nnew hydrodynamical code that properly describes for the global viscous\nevolution of the disk. Initially both planets migrate towards the Sun, and\nSaturn's migration tends to be faster. As a consequence, they eventually end up\nlocked in a mean motion resonance. If this happens in the 2:3 resonance, the\nresonant motion is particularly stable, and the gaps opened by the planets in\nthe disk may overlap. This causes a drastic change in the torque balance for\nthe two planets, which substantially slows down the planets' inward migration.\nIf the gap overlap is substantial, planet migration may even be stopped or\nreversed. As the widths of the gaps depend on disk viscosity and scale height,\nthis mechanism is particularly efficient in low viscosity, cool disks. We\ndiscuss the compatibility of our results with the initial conditions adopted in\nTsiganis et al. (2005) and Gomes et al. (2005) to explain the current orbital\narchitecture of the giant planets and the origin of the Late Heavy Bombardment\nof the Moon.", "We model numerically the partial normal contact of two elastic rough surfaces\nwith highly correlated asperities. Facing surfaces are unmated and described as\nself-affine with a Hurst exponent H. The numerical algorithm is based on\nFourier acceleration and allows efficient simulation of very large systems. The\nforce, F, versus contact area, A, characteristics follows the law F = c\nA^[(1+H)/2] in accordance with the suggestion of Roux et al. (Europhys. Lett.\n23, 277 (1993)). However finite size corrections are very large even for\n512X512 systems where the effective exponent is still 20% larger than its\nasymptotic value.", "Title: From favorable atomic configurations to supershell structures: a new\ninterpretation of conductance histograms Authors: A. Hasmy (IVIC), E. Medina\n(IVIC), P.A. Serena (CSIC,IVIC) Comments: 7 pages, 3 figures,\ncond-mat.anwar.10825 Subj-class: Soft Condensed Matter", "During the last three decades, evidence has mounted that star and planet\nformation is not an isolated process, but is influenced by current and previous\ngenerations of stars. Although cool stars form in a range of environments, from\nisolated globules to rich embedded clusters, the influences of other stars on\ncool star and planet formation may be most significant in embedded clusters,\nwhere hundreds to thousands of cool stars form in close proximity to OB stars.\nAt the cool stars 14 meeting, a splinter session was convened to discuss the\nrole of environment in the formation of cool stars and planetary systems; with\nan emphasis on the ``hot'' environment found in rich clusters. We review here\nthe basic results, ideas and questions presented at the session. We have\norganized this contribution into five basic questions: what is the typical\nenvironment of cool star formation, what role do hot star play in cool star\nformation, what role does environment play in planet formation, what is the\nrole of hot star winds and supernovae, and what was the formation environment\nof the Sun? The intention is to review progress made in addressing each\nquestion, and to underscore areas of agreement and contention.", "The boundary conditions of the heliosphere are set by the ionization, density\nand composition of inflowing interstellar matter. Constraining the properties\nof the Local Interstellar Cloud (LIC) at the heliosphere requires radiative\ntransfer ionization models. We model the background interstellar radiation\nfield using observed stellar FUV and EUV emission and the diffuse soft X-ray\nbackground. We also model the emission from the boundary between the LIC and\nthe hot Local Bubble (LB) plasma, assuming that the cloud is evaporating\nbecause of thermal conduction. We create a grid of models covering a plausible\nrange of LIC and LB properties, and use the modeled radiation field as input to\nradiative transfer/thermal equilibrium calculations using the Cloudy code. Data\nfrom in situ observations of He^O, pickup ions and anomalous cosmic rays in the\nheliosphere, and absorption line measurements towards epsilon CMa were used to\nconstrain the input parameters. A restricted range of assumed LIC HI column\ndensities and LB plasma temperatures produce models that match all the\nobservational constraints. The relative weakness of the constraints on N(HI)\nand T_h contrast with the narrow limits predicted for the H^O and electron\ndensity in the LIC at the Sun, n(H^0) = 0.19 - 0.20 cm^-3, and n(e) = 0.07 +/-\n0.01 cm^-3. Derived abundances are mostly typical for low density gas, with\nsub-solar Mg, Si and Fe, possibly subsolar O and N, and S about solar; however\nC is supersolar. The interstellar gas at the Sun is warm, low density, and\npartially ionized, with n(H) = 0.23 - 0.27 cm^-3, T = 6300 K, X(H^+) ~ 0.2, and\nX(He^+) ~ 0.4. These results appear to be robust since acceptable models are\nfound for substantially different input radiation fields. Our results favor low\nvalues for the reference solar abundances for the LIC composition.", "A system of a metastable phase with a pseudo continuous set of the\nheterogeneous centers is considered. An analytical theory for kinetics of decay\nof the metastable phase in such a system is constructed. The free energy of\nformation of a critical embryo is assumed to be known in the macroscopic\napproach as well as the solvatation energy. The theory constructed below is\nbased on the quasistationary approximation for the nucleation rate.", "Using a density functional method, we investigate the properties of liquid\n4He droplets doped with atoms (Ne and Xe) and molecules (SF_6 and HCN). We\nconsider the case of droplets having a quantized vortex pinned to the dopant. A\nliquid drop formula is proposed that accurately describes the total energy of\nthe complex and allows one to extrapolate the density functional results to\nlarge N. For a given impurity, we find that the formation of a\ndopant+vortex+4He_N complex is energetically favored below a critical size\nN_cr. Our result support the possibility to observe quantized vortices in\nhelium droplets by means of spectroscopic techniques.", "We detect a dip of 20-45% in the surface brightness and number counts of NVSS\nsources smoothed to a few degrees at the location of the WMAP cold spot. The\ndip has structure on scales of approximately 1-10 degrees. Together with\nindependent all-sky wavelet analyses, our results suggest that the dip in\nextragalactic brightness and number counts and the WMAP cold spot are\nphysically related, i.e., that the coincidence is neither a statistical anomaly\nnor a WMAP foreground correction problem. If the cold spot does originate from\nstructures at modest redshifts, as we suggest, then there is no remaining need\nfor non-Gaussian processes at the last scattering surface of the CMB to explain\nthe cold spot. The late integrated Sachs-Wolfe effect, already seen\nstatistically for NVSS source counts, can now be seen to operate on a single\nregion. To create the magnitude and angular size of the WMAP cold spot requires\na ~140 Mpc radius completely empty void at z<=1 along this line of sight. This\nis far outside the current expectations of the concordance cosmology, and adds\nto the anomalies seen in the CMB.", "We propose a new model for the nature of the low temperature phase of a\ngeometrically frustrated antiferromgnet (AFM) with a Kagome lattice,\nSrCr$_{8-x}$Ga$_{4+x}$O$_{19}$. We propose that the long-range dipolar\ninteraction between the magnetic Cr$^{3+}$ ions introduces correlations in\ntheir dynamics. The dipolar ground-state has the spins performing correlated\nzero-point oscillations in a coherent state with a well defined global phase\nand a complex order-parameter (i.e. Off-Diagonal Long Range Order). We\ncalculate the magnon excitations of such a dipolar array and we find good\nagreement with the spin-wave velocities infered from measurements of the\nspecific-heat. Various experimental properties of these materials are naturally\nexplained by such a model.", "Swift triggered on a precursor to the main burst of GRB 061121 (z=1.314),\nallowing observations to be made from the optical to gamma-ray bands. Many\nother telescopes, including Konus-Wind, XMM-Newton, ROTSE and the Faulkes\nTelescope North, also observed the burst. The gamma-ray, X-ray and UV/optical\nemission all showed a peak ~75s after the trigger, although the optical and\nX-ray afterglow components also appear early on - before, or during, the main\npeak. Spectral evolution was seen throughout the burst, with the prompt\nemission showing a clear positive correlation between brightness and hardness.\nThe Spectral Energy Distribution (SED) of the prompt emission, stretching from\n1eV up to 1MeV, is very flat, with a peak in the flux density at ~1keV. The\noptical-to-X-ray spectra at this time are better fitted by a broken, rather\nthan single, power-law, similar to previous results for X-ray flares. The SED\nshows spectral hardening as the afterglow evolves with time. This behaviour\nmight be a symptom of self-Comptonisation, although circumstellar densities\nsimilar to those found in the cores of molecular clouds would be required. The\nafterglow also decays too slowly to be accounted for by the standard models.\nAlthough the precursor and main emission show different spectral lags, both are\nconsistent with the lag-luminosity correlation for long bursts. GRB 061121 is\nthe instantaneously brightest long burst yet detected by Swift. Using a\ncombination of Swift and Konus-Wind data, we estimate an isotropic energy of\n2.8x10^53 erg over 1keV - 10MeV in the GRB rest frame. A probable jet break is\ndetected at ~2x10^5s, leading to an estimate of ~10^51 erg for the\nbeaming-corrected gamma-ray energy.", "Since the discovery of the first L dwarf 19 years ago and the discovery of\nthe first T dwarf 7 years after that, we have amassed a large list of these\nobjects, now numbering almost six hundred. Despite making headway in\nunderstanding the physical chemistry of their atmospheres, some important\nissues remain unexplained. Three of these are the subject of this paper: (1)\nWhat is the role of \"second parameters\" such as gravity and metallicity in\nshaping the emergent spectra of L and T dwarfs? Can we establish a robust\nclassification scheme so that objects with unusual values of log(g) or [M/H],\nunusual dust content, or unresolved binarity are easily recognized? (2) Which\nphysical processes drive the unusual behavior at the L/T transition? Which\nobservations can be obtained to better confine the problem? (3) What will\nobjects cooler than T8 look like? How will we know a Y dwarf when we first\nobserve one?", "Six of the eight double neutron stars known in the Galactic disk have low\norbital eccentricities (< 0.27) indicating that their second-born neutron stars\nreceived only very small velocity kicks at birth. This is similar to the case\nof the B-emission X-ray binaries, where a sizable fraction of the neutron stars\nreceived hardly any velocity kick at birth (Pfahl et al. 2002). The masses of\nthe second-born neutron stars in five of the six low-eccentricity double\nneutron stars are remarkably low (between 1.18 and 1.30 Msun). It is argued\nthat these low-mass, low-kick neutron stars were formed by the electron-capture\ncollapse of the degenerate O-Ne-Mg cores of helium stars less massive than\nabout 3.5 Msun, whereas the higher-mass, higher kick-velocity neutron stars\nwere formed by the collapses of the iron cores of higher initial mass. The\nabsence of low-velocity single young radio pulsars (Hobbs et al. 2005) is\nconsistent with the model proposed by Podsiadlowski et al. (2004), in which the\nelectron-capture collapse of degenerate O-Ne-Mg cores can only occur in binary\nsystems, and not in single stars.", "The melting of elemental solids is modelled as a dislocation-mediated\ntransition on a lattice. Statistical mechanics of linear defects is used to\nobtain a new relation between melting temperature, crystal structure, atomic\nvolume, and shear modulus that is accurate to 17% for at least half of the\nPeriodic Table.", "The shift of a maxon-roton He-4 excitation spectrum E via the He-3 admixture\nis considered theoretically. The Bogoliubov formula for E(\\rho, g) as a\nfunction of Bose-condensate density \\rho and of He-4/He-4 interaction g is used\nas an element of partition function formalism of the whole system, presented in\nthe form of a path (functional) integral. The dependence of \\rho on g,\nHe-4/He-3 interaction \\lambda as well as on the pressure P, induced by He-3\nadmixture, is taken into account. The new model of g, suitable for analytical\ncalculations, is used for a description of a change of P within the constant\nvolume. The cases of positive and negative shifts are found as the result of\ncompetition between interactions g and \\lambda.", "We discuss the possibility of GLAST detecting gamma-rays from the\nannihilation of neutralino dark matter in the Galactic halo. We have used \"Via\nLactea\", currently the highest resolution simulation of Galactic cold dark\nmatter substructure, to quantify the contribution of subhalos to the\nannihilation signal. We present a simulated allsky map of the expected\ngamma-ray counts from dark matter annihilation, assuming standard values of\nparticle mass and cross section. In this case GLAST should be able to detect\nthe Galactic center and several individual subhalos.", "We consider a possible technique for mode-locking an atom laser, based on the\ngeneration of a dark soliton in a ring-shaped Bose-Einstein condensate, with\nrepulsive atomic interactions. The soliton is a kink, with angular momentum per\nparticle equal to \\hbar/2. It emerges naturally, when the condensate is stirred\nat the soliton velocity, and subsequently outcoupled with a periodic Raman\npulse-train. The result is a replicating coherent field inside the atom laser.\nWe give a numerical demonstration of the generation and stabilization of the\nsoliton.", "We develop a systematic semiclassical approximation scheme for quantum Hall\nskyrmions near filling factors $\\nu = {1 \\over 2n+1}$, which is exact in the\nlong wavelength limit. We construct a coherent state basis for the Hilbert\nspace of Chern-Simons gauge fields and composite bosons with spin. These states\nare projected to the physical gauge invariant subspace and their wavefunctions\nexplicitly evaluated. The lowest Landau level (LLL) condition is shown to be\nequivalent to an analyticity condition on the parameters.\n  The matrix elements of physical observables between these states are shown to\nbe calculable in the limit of small amplitude long wavelength density\nfluctuations. The electric charge density is shown to be proportional to the\ntoplological charge density if and only if the LLL condition is satisfied.\n  We then show that these states themselves form a generalised coherent state\nbasis, parameterised by the values of physical observables. The theory can\ntherefore be written in terms of these gauge invariant bosonic fields in the\nlong wavelength regime. The off diagonal matrix elements of observables in\nthese coherent states are computed and shown to vanish in the long wavelength\nlimit. Thus we are able to prove that the classical description of the skyrmion\nis exact in the limit of large skyrmions.", "We search for galaxy counterparts to damped Lyman-alpha absorbers (DLAs) at\nz>2 towards nine quasars, which have 14 DLAs and 8 sub-DLAs in their spectra.\nWe use integral field spectroscopy to search for Ly-alpha emission line objects\nat the redshifts of the absorption systems. Besides recovering two previously\nconfirmed objects, we find six statistically significant candidate Ly-alpha\nemission line objects. The candidates are identified as having wavelengths\nclose to the DLA line where the background quasar emission is absorbed. In\ncomparison with the six currently known Ly-alpha emitting DLA galaxies the\ncandidates have similar line fluxes and line widths, while velocity offsets\nbetween the emission lines and systemic DLA redshifts are larger. The impact\nparameters are larger than 10 kpc, and lower column density systems are found\nat larger impact parameters. Assuming that a single gas cloud extends from the\nQSO line of sight to the location of the candidate emission line, we find that\nthe average candidate DLA galaxy is surrounded by neutral gas with an\nexponential scale length of ~5 kpc.", "We calculate the damping of condensate collective excitations at finite\ntemperatures arising from the lack of equilibrium between the condensate and\nthermal atoms. We neglect the non-condensate dynamics by fixing the thermal\ncloud in static equilibrium. We derive a set of generalized Bogoliubov\nequations for finite temperatures that contain an explicit damping term due to\ncollisional exchange of atoms between the two components. We have numerically\nsolved these Bogoliubov equations to obtain the temperature dependence of the\ndamping of the condensate modes in a harmonic trap. We compare these results\nwith our recent work based on the Thomas-Fermi approximation.", "We propose an experiment, based on two consecutive Bragg pulses, to measure\nthe momentum distribution of quasiparticle excitations in a trapped Bose gas at\nlow temperature. With the first pulse one generates a bunch of excitations\ncarrying momentum $q$, whose Doppler line is measured by the second pulse. We\nshow that this experiment can provide direct access to the amplitudes $u_{q}$\nand $v_{q}$ characterizing the Bogoliubov transformations from particles to\nquasiparticles. We simulate the behavior of the nonuniform gas by numerically\nsolving the time dependent Gross-Pitaevskii equation.", "We have conducted an extensive wide-field imaging survey for Cepheid\nvariables in the Local Group irregular galaxy WLM. From data obtained on 101\nnights, we have discovered 60 Cepheids which include 14 of the 15 Cepheid\nvariables previously detected by Sandage and Carlson. Down to a period of 3\ndays, our Cepheid survey in WLM should be practically complete. Importantly, we\nhave found for the first time a long-period Cepheid (P=54.2 days) in this\ngalaxy, alleviating the puzzle that WLM with its many blue, massive stars does\nnot contain Cepheids with periods longer than about 10 days. Our data define\ntight period-luminosity relations in V, I and the reddening-free Wesenheit\nmagnitude ${\\rm W}_{\\rm I}$ which are all extremely well fit by the\ncorresponding slopes of the LMC Cepheid PL relation, suggesting no change of\nthe PL relation slope down to a Cepheid metal abundance of about -1.0 dex, in\nagreement with other recent studies. We derive a true distance modulus to WLM\nof 25.144 $\\pm$0.03 (r) $\\pm$0.07 (s) mag from our data, in good agreement with\nthe earlier 24.92 $\\pm$ 0.21 mag determination of Lee, Freedman and Madore\n(1993a) from Cepheid variables. The quoted value of the systematic uncertainty\ndoes not include the contribution from the LMC distance which we have assumed\nto be 18.50 mag, as in the previous papers in our project.", "Chiral order of the Josephson-junction ladder with half a flux quantum per\nplaquette is studied by means of the exact diagonalization method. We consider\nan extreme quantum limit where each superconductor grain (order parameter) is\nrepresented by S=1/2 spin. So far, the semi-classical S -> \\infty case, where\neach spin reduces to a plane rotator, has been considered extensively. We found\nthat in the case of S=1/2, owing to the strong quantum fluctuations, the chiral\n(vortex lattice) order becomes dissolved except in a region, where attractive\nintrachain and, to our surprise, repulsive interchain interactions both exist.\nOn the contrary, for considerably wide range of parameters, the superconductor\n(XY) order is kept critical. The present results are regarded as a\ndemonstration of the critical phase accompanying chiral-symmetry breaking\npredicted for frustrated XXZ chain field-theoretically.", "A structure with a massive group in its center and a cool expansion outflow\noutside is studied around the Cen A galaxy with the use of the Hubble Space\nTelescope observations. It is demonstrated that the dynamics of the flow is\ndominated by the antigravity of the dark energy background. The density of dark\nenergy in the cell is estimated to be near the global cosmological density.\nThis agrees with our previous result from the neighborhood of the Local group.\nA notion of the ``Hubble cell'' is introduced as a building block of the local\nstructure of the universe.", "We explore the main physical processes which potentially affect the\ntopological signal in the Cosmic Microwave Background (CMB) for a range of\ntoroidal universes. We consider specifically reionisation, the integrated\nSachs-Wolfe (ISW) effect, the size of the causal horizon, topological defects\nand primordial gravitational waves. We use three estimators: the information\ncontent, the S/N statistic and the Bayesian evidence. While reionisation has\nnearly no effect on the estimators, we show that taking into account the ISW\nstrongly decreases our ability to detect the topological signal. We also study\nthe impact of varying the relevant cosmological parameters within the 2 sigma\nranges allowed by present data. We find that only Omega_Lambda, which\ninfluences both ISW and the size of the causal horizon, significantly alters\nthe detection for all three estimators considered here.", "Magnetic fields likely play a key role in the dynamics and evolution of\nprotoplanetary discs. They have the potential to efficiently transport angular\nmomentum by MHD turbulence or via the magnetocentrifugal acceleration of\noutflows from the disk surface, and magnetically-driven mixing has implications\nfor disk chemistry and evolution of the grain population. However, the weak\nionisation of protoplanetary discs means that magnetic fields may not be able\nto effectively couple to the matter. I present calculations of the ionisation\nequilibrium and magnetic diffusivity as a function of height from the disk\nmidplane at radii of 1 and 5 AU. Dust grains tend to suppress magnetic coupling\nby soaking up electrons and ions from the gas phase and reducing the\nconductivity of the gas by many orders of magnitude. However, once grains have\ngrown to a few microns in size their effect starts to wane and magnetic fields\ncan begin to couple to the gas even at the disk midplane. Because ions are\ngenerally decoupled from the magnetic field by neutral collisions while\nelectrons are not, the Hall effect tends to dominate the diffusion of the\nmagnetic field when it is able to partially couple to the gas.\n  For a standard population of 0.1 micron grains the active surface layers have\na combined column of about 2 g/cm^2 at 1 AU; by the time grains have aggregated\nto 3 microns the active surface density is 80 g/cm^2. In the absence of grains,\nx-rays maintain magnetic coupling to 10% of the disk material at 1 AU (150\ng/cm^2). At 5 AU the entire disk thickness becomes active once grains have\naggregated to 1 micron in size.", "We investigate the origin of the GRB 060912A, which has observational\nproperties that make its classification as either a long or short burst\nambiguous. Short duration GRBs (SGRBs) are thought to have typically lower\nenergies than long duration bursts, can be found in galaxies with populations\nof all ages and are likely to originate from different progenitors to the long\nduration bursts. However, it has become clear that duration alone is\ninsufficient to make a distinction between the two populations in many cases,\nleading to a desire to find additional discriminators of burst type. GRB\n060912A had a duration of 6 s and occurred only ~10 arcsec from a bright, low\nredshift ($z=0.0936$) elliptical galaxy, suggesting that this may have been the\nhost, which would favour it being a short-burst. However, our deep optical\nimaging and spectroscopy of the location of GRB 060912A using the VLT shows\nthat GRB 060912A more likely originates in a distant star forming galaxy at\nz=0.937, and is most likely a long burst. This demonstrates the risk in\nidentifying bright, nearby galaxies as the hosts of given GRBs without further\nsupporting evidence. Further, it implies that, in the absence of secure\nidentifications, \"host\" type, or more broadly discriminators which rely on\ngalaxy redshifts, may not be good indicators of the true nature of any given\nGRB.", "We consider the idea of bond ordering as a model for glass transition: a\ngeneric covalently bonded liquid may substantially reduce its energy through\nbond ordering, without undergoing significant structural order. This concept is\ndeveloped for a model system using quantities such as a bond order parameter\nand susceptibility which provide new identification for calorimetric glass\ntransition temperature. Monte Carlo simulation results exhibit bond ordering at\nintermediate temperatures uncorrelated with any long-range structural ordering.\nAlso discussed are various other implications of bond-ordering model for glass\ntransition.", "We describe the implementation of total angular momentum dependent\npseudopotentials in a plane wave formulation of density functional theory. Our\napproach thus goes beyond the scalar-relativistic approximation usually made in\nab initio pseudopotential calculations and explicitly includes spin-orbit\ncoupling. We outline the necessary extensions and compare the results to\navailable all-electron calculations and experimental data.", "There are two promising scenarios that explain the ankle, which is a dip in\nthe spectrum of cosmic rays at $\\sim 10^{19}$ eV. A scenario interprets the\nankle as the transition from Galactic to extragalactic cosmic rays ({\\it\nankle-transition scenario}), while the other is that the dip caused by pair\nproduction on the cosmic microwave background radiation ({\\it proton-dip\nscenario}). In this paper, we consider whether cosmogenic neutrinos can be a\nclue to judge which scenario is favored. We calculated the fluxes of cosmogenic\nneutrinos following these scenarios with plausible physical parameter sets, and\nfound several important features as follows. First of all, the neutrino flux at\n$\\sim 10^{20}$ eV becomes much higher in the ankle-transition scenario as long\nas the maximum energy of the cosmic rays at sources is sufficiently high. On\nthe other hand, the neutrino spectrum has a characteristic peak at $\\sim\n10^{16}$ eV in the proton-dip scenario on the condition that extragalactic\nprotons significantly contribute to the observed cosmic rays down to $10^{17}$\neV. Thus, we conclude cosmogenic neutrinos should give us a clue to judge which\nscenario is favored, unless these features are masked by the neutrino\nbackground coming from possible, powerful neutrino sources such as AGNs and\nGRBs. We also found an interesting feature that the neutrino flux at $\\sim\n10^{18}$ eV depends only on the cosmological evolution of the cosmic ray\nsources. That means cosmogenic neutrinos with the energy bring us information\non the cosmological evolution of the sources of ultra-high energy cosmic rays.\nFinally, we compare the fluxes of cosmogenic neutrinos with the expected\nsensitivity curves of several neutrino detectors, and conclude the detection of\ncosmogenic neutrinos in the near future is promising.", "Recent experimental evidence suggest the existence of three distinct\nV-valence states (V^{+4}, V^{+4.5} and V^{+5}) in the low-temperature phase of\nNaV_2O_5 in apparent discrepancy with the observed spin-gap. We investigate a\nnovel spin cluster model, consisting of weakly coupled, frustrated four-spin\nclusters aligned along the crystallographic b-axis that was recently proposed\nto reconcile these experimental observations. We have studied the phase diagram\nand the magnon dispersion relation of this model using DMRG, exact\ndiagonalization and a novel cluster-operator theory. We find a spin-gap for all\nparameter values and two distinct phases, a cluster phase and a Haldane phase.\nWe evaluate the size of the gap and the magnon dispersion and find no parameter\nregime which would reproduce the experimental results. We conclude that this\nmodel is inappropriate for the low-temperature regime of NaV_2O_5.", "We review some recent results on the relations between sandpiles and a class\nof absorbing state phase transitions. We use the concept of fixed energy\nsandpiles (FES), in which external driving and dissipation are absent.\n  FES are shown to exhibit an absorbing state transition with critical\nproperties coinciding with those of the corresponding sandpile model. We\npropose a set of Langevin equations capturing the relevant features of this\ntransition. These equations characterize the universality class of systems with\nan infinite number of absorbing states and a static conserved field coupled to\nthe order parameter. Different models in this class are identified, and strong\nevidence is presented showing that the Manna sandpile, as well as some other\nstochastic sandpiles, belong in this universality class. Finally some open\nproblems and questions are discussed.", "We present diffraction limited, 10um imaging polarimetry data for the central\nregions of the archetypal Seyfert AGN, NGC1068. The position angle of\npolarization is consistent with three dominant polarizing mechanisms. We\nidentify three distinct regions of polarization: (a) north of the nucleus,\narising from aligned dust in the NLR, (b) south, east and west of the nucleus,\nconsistent with dust being channeled toward the central engine and (c) a\ncentral minimum of polarization consistent with a compact (<22pc) torus. These\nobservations provide continuity between the geometrically and optically thick\ntorus and the host galaxy's nuclear environments. These images represent the\nfirst published mid-IR polarimetry from an 8-m class telescope and illustrate\nthe potential of such observations.", "Our objective is to study the vertical dust distribution in the circumbinary\nring of the binary system GG Tau and to search for evidence of stratification,\none of the first steps expected to occur during planet formation.\n  We present a simultaneous analysis of four scattered light images spanning a\nrange of wavelength from 800 nm to 3800 nm and compare them with (i) a\nparametric prescription for the vertical dust stratification, and (ii) with the\nresults of SPH bi-fluid hydrodynamic calculations.\n  The parametric prescription and hydrodynamical calculations of stratification\nboth reproduce the observed brightness profiles well. These models also provide\na correct match for the observed star/ring integrated flux ratio. Another\nsolution with a well-mixed, but ``exotic'', dust size distribution also matches\nthe brightness profile ratios but fails to match the star/ring flux ratio.\nThese results give support to the presence of vertical stratification of the\ndust in the ring of GG Tau and further predict the presence of a radial\nstratification also.", "We present a new code for calculating the Fe Kalpha line profiles from\nrelativistic accretion disks with finite thickness around a rotating black\nhole. The thin Keplerian accretion disk must become thicker and sub-Keplerian\nwith increasing accretion rates. We here embark on, for the first time, a fully\nrelativistic computation which is aimed at gaining an insight into the effects\nof geometrical thickness and the sub-Keplerian orbital velocity on the line\nprofiles. This code is also well-suited to produce accretion disk images.", "Parametric simultaneous solitary wave (simulton) excitations are shown\npossible in nonlinear lattices. Taking a one-dimensional diatomic lattice with\na cubic potential as an example we consider the nonlinear coupling between the\nupper cutoff mode of acoustic branch (as a fundamental wave) and the upper\ncutoff mode of optical branch (as a second harmonic wave). Based on a\nquasi-discreteness approach the Karamzin-Sukhorukov equations for two slowly\nvarying amplitudes of the fundamental and the second harmonic waves in the\nlattice are derived when the condition of second harmonic generation is\nsatisfied. The lattice simulton solutions are explicitly given and the results\nshow that these lattice simultons can be nonpropagating when the wave vectors\nof the fundamental wave and the second harmonic waves are exactly at $\\pi/a$\n(where $a$ is the lattice constant) and zero, respectively.", "Recently it was experimentally demonstrated that sputtering under normal\nincidence leads to the formation of spatially ordered uniform nanoscale islands\nor holes. Here we show that these nanostructures have inherently nonlinear\norigin, first appearing when the nonlinear terms start to dominate the surface\ndynamics. Depending on the sign of the nonlinear terms, determined by the shape\nof the collision cascade, the surface can develop regular islands or holes with\nidentical dynamical features, and while the size of these nanostructures is\nindependent of flux and temperature, it can be modified by tuning the ion\nenergy.", "We quantify the variability of faint unresolved optical sources using a\ncatalog based on multiple SDSS imaging observations. The catalog covers SDSS\nStripe 82, and contains 58 million photometric observations in the SDSS ugriz\nsystem for 1.4 million unresolved sources. In each photometric bandpass we\ncompute various low-order lightcurve statistics and use them to select and\nstudy variable sources. We find that 2% of unresolved optical sources brighter\nthan g=20.5 appear variable at the 0.05 mag level (rms) simultaneously in the g\nand r bands. The majority (2/3) of these variable sources are low-redshift (<2)\nquasars, although they represent only 2% of all sources in the adopted\nflux-limited sample. We find that at least 90% of quasars are variable at the\n0.03 mag level (rms) and confirm that variability is as good a method for\nfinding low-redshift quasars as is the UV excess color selection (at high\nGalactic latitudes). We analyze the distribution of lightcurve skewness for\nquasars and find that is centered on zero. We find that about 1/4 of the\nvariable stars are RR Lyrae stars, and that only 0.5% of stars from the main\nstellar locus are variable at the 0.05 mag level. The distribution of\nlightcurve skewness in the g-r vs. u-g color-color diagram on the main stellar\nlocus is found to be bimodal (with one mode consistent with Algol-like\nbehavior). Using over six hundred RR Lyrae stars, we demonstrate rich halo\nsubstructure out to distances of 100 kpc. We extrapolate these results to\nexpected performance by the Large Synoptic Survey Telescope and estimate that\nit will obtain well-sampled 2% accurate, multi-color lightcurves for ~2 million\nlow-redshift quasars, and will discover at least 50 million variable stars.", "To use galaxy clusters as a cosmological probe, it is important to account\nfor their triaxiality. Assuming that the triaxial shapes of galaxy clusters are\ninduced by the tidal interaction with the surrounding matter, Lee and Kang\nrecently developed a reconstruction algorithm for the measurement of the axial\nratio of a triaxial cluster. We examine the validity of this reconstruction\nalgorithm by performing an observational test of it with the Virgo cluster as a\ntarget. We first modify the LK06 algorithm by incorporating the two dimensional\nprojection effect. Then, we analyze the 1275 member galaxies from the Virgo\nCluster Catalogue and find the projected direction of the Virgo cluster major\naxis by measuring the anisotropy in the spatial distribution of the member\ngalaxies in the two dimensional projected plane. Applying the modified\nreconstruction algorithm to the analyzed data, we find that the axial ratio of\nthe triaxial Virgo cluster is (1: 0.54 : 0.73). This result is consistent with\nthe recent observational report from the Virgo Cluster Survey, proving the\nrobustness of the reconstruction algorithm. It is also found that at the inner\nradii the shape tends to be more like prolate. We discuss the possible effect\nof the Virgo cluster triaxiality on the mass estimation.", "It has been suggested that X-ray observations of rapidly variable Seyfert\ngalaxies may hold the key to probe the gas orbital motions in the innermost\nregions of accretion discs around black holes and, thus, trace flow patterns\nunder the effect of the hole strong gravitational field. We explore this\npossibility analizing XMM-Newton observations of the seyfert 1 galaxy NGC 3783.\nA detiled time-resolved spectral analysis is performed down to the shortest\npossible time-scales (few ks) using \"excess maps\" and cross-correlating light\ncurves in different energy bands. In addition to a constant core of the Fe K\nalpha line, we detected a variable and redshifted Fe K alpha emission feature\nbetween 5.3-6.1 keV. The line exhibits a modulation on a time-scale of 27 ks\nthat is similar to and in phase with a modulation of the 0.3-10 keV source\ncontinuum. The time-scale of the correlated variability of the redshifted Fe\nline and continuum agrees with the local dynamical time-scale of the accretion\ndisc at 10 r_g around a black hole of 10^7 M_sun. Given the shape of the\nredshfted line emission and the overall X-ray variability pattern, the line is\nlikely to arise from the relativistic region near the black hole.", "Josephson junction arrays are ideal model systems where a variety of\nphenomena, phase transitions, frustration effects, vortex dynamics, chaos, to\nmention a few of them, can be studied in a controlled way. In this review we\nfocus on the quantum dynamical properties of low capacitance Josephson junction\narrays. The two characteristic energy scales in these systems are the Josephson\nenergy, associated to the tunneling of Cooper pairs between neighboring\nislands, and the charging energy, which is the energy cost to add an extra\nelectron charge to a neutral island. The phenomena described in this review\nstem from the competition between single electron effects with the Josephson\neffect. One example is the (quantum) Superconductor-Insulator phase transition\nwhich occurs by varying the ratio between the coupling constants and/or by\nmeans of external magnetic/electric fields. We will describe how the phase\ndiagram depends on the various control paramters and the transport properties\nclose to the quantum critical point. The relevant topological excitations on\nthe superconducting side of the phase diagram are vortices. In low capacitance\njunction arrays vortices behave as massive underdamped particles that can\nexhibit quantum behaviour. We will report on the various experiments and\ntheoretical treatments on quantum vortex dynamics.", "We introduce a procedure developed by the ``Teramo Stellar Populations\nTools'' group (Teramo-SPoT), specifically optimized to obtain realistic\nsimulations of CCD images of elliptical galaxies.\n  Particular attention is devoted to include the Surface Brightness Fluctuation\n(SBF) signal observed in ellipticals and to simulate the Globular Cluster (GC)\nsystem in the galaxy, and the distribution of background galaxies present in\nreal CCD frames. In addition to the physical properties of the simulated\nobjects - galaxy distance and brightness profile, luminosity function of GC and\nbackground galaxies, etc. - the tool presented allows the user to set some of\nthe main instrumental properties - FoV, zero point magnitude, exposure time,\netc.", "We study the nonlinear evolution of the baryon acoustic oscillations (BAO) in\nthe dark matter power spectrum and correlation function using renormalized\nperturbation theory (RPT). In a previous paper we showed that RPT successfully\npredicts the damping of acoustic oscillations; here we extend our calculation\nto the enhancement of power due to mode-coupling. We show that mode-coupling\ngenerates additional oscillations that are out of phase with those in the\nlinear spectrum, leading to shifts in the scales of oscillation nodes defined\nwith respect to a smooth spectrum. When Fourier transformed, these out of phase\noscillations induce percent-level shifts in the acoustic peak of the two-point\ncorrelation function. We present predictions for these shifts as a function of\nredshift; these should be considered as a robust lower limit to the more\nrealistic case that includes in addition redshift distortions and galaxy bias.\nWe show that these nonlinear effects occur at very large scales, leading to a\nbreakdown of linear theory at scales much larger than commonly thought. We\ndiscuss why virialized halo profiles are not responsible for these effects,\nwhich can be understood from basic physics of gravitational instability. Our\nresults are in excellent agreement with numerical simulations, and can be used\nas a starting point for modeling BAO in future observations. To meet this end,\nwe suggest a simple physically motivated model to correct for the shifts caused\nby mode-coupling.", "A complete model of helium-like line and continuum emission has been\nincorporated into the plasma simulation code Cloudy. All elements between He\nand Zn are treated, any number of levels can be considered, and radiative and\ncollisional processes are included. This includes photoionization from all\nlevels, line transfer including continuum pumping and destruction by background\nopacities, scattering, and collisional processes. The model is calculated\nself-consistently along with the ionization and thermal structure of the\nsurrounding nebula. The result is a complete line and continuum spectrum of the\nplasma. Here we focus on the ions of the He I sequence and reconsider the\nstandard helium-like X-ray diagnostics. We first consider semi-analytical\npredictions and compare these with previous work in the low-density,\noptically-thin limit. We then perform numerical calculations of helium-like\nX-ray emission (such as is observed in some regions of Seyferts) and predict\nline ratios as a function of ionizing flux, hydrogen density, and column\ndensity. In particular, we demonstrate that, in photoionized plasmas, the\n$R$-ratio, a density indicator in a collisional plasma, depends on the\nionization fraction and is strongly affected by optical depth for large column\ndensities. We also introduce the notion that the $R$-ratio is a measure of the\nincident continuum at UV wavelengths. The $G$-ratio, which is\ntemperature-sensitive in a collisional plasma, is also discussed, and shown to\nbe strongly affected by continuum pumping and optical depth as well. These\ndistinguish a photoionized plasma from the more commonly studied collisional\ncase.", "The evolution of the spin gap of a 2-leg ladder upon doping depends upon the\nnature of the lowest triplet excitations in a ladder with two holes. Here we\nstudy this evolution using various numerical techniques for a t-t'-J ladder as\nthe next-near-neighbor hopping t' is varied. We find that depending on the\nvalue of t', the spin gap can evolve continuously or discontinuously and the\nlowest triplet state can correspond to a magnon, a bound magnon-hole-pair, or\ntwo separate quasi-particles. Previous experimental results on the\nsuperconducting two-leg ladder Sr12Ca2Cu24O41 are discussed.", "We theoretically study the creep of vortex matter in superconductors. The low\ntemperatures experimental phenomenology, previously interpreted in terms of\n``quantum tunnelling'' of vortices, is reproduced by Monte Carlo simulations of\na purely ``classical'' vortex model. We demonstrate that a non-zero creep rate\nin the limit of vanishing temperature is to be expected in systems with slow\nrelaxations as a consequence of their off-equilibrium evolution in a complex\nfree energy landscape.", "The low energy spectra of some gamma-ray bursts' show excess components\nbeside the power-law dependence. The consequences of such a feature allows to\nestimate the gamma photometric redshift of the long gamma-ray bursts in the\nBATSE Catalog. There is good correlation between the measured optical and the\nestimated gamma photometric redshifts. The estimated redshift values for the\nlong bright gamma-ray bursts are up to z=4, while for the the faint long bursts\n- which should be up to z=20 - the redshifts cannot be determined unambiguously\nwith this method. The redshift distribution of all the gamma-ray bursts with\nknown optical redshift agrees quite well with the BATSE based gamma photometric\nredshift distribution.", "We present a synthetic spectral analysis of nearly the entire far ultraviolet\nInternational Ultraviolet Explorer (IUE) archive of spectra of dwarf novae in\nor near outburst. The study includes 46 systems of all dwarf nova subtypes both\nabove and below the period gap. The spectra were uniformly analyzed using\nsynthetic spectral codes for optically thick accretion disks and stellar\nphotospheres along with the best-available distance measurements or estimates.\nWe present newly estimated accretion rates and discuss the implications of our\nstudy for disk accretion physics and CV evolution.", "The electronic properties of carbon nanotubes are investigated in the\npresence of disorder and a magnetic field parallel or perpendicular to the\nnanotube axis. In the parallel field geometry, the $\\phi_{0}(=hc/e)$-periodic\nmetal-insulator transition (MIT) induced in metallic or semiconducting\nnanotubes is shown to be related to a chirality-dependent shifting of the\nenergy of the van Hove singularities (VHSs). The effect of disorder on this\nmagnetic field-related mechanism is considered with a discussion of mean free\npaths, localization lengths and magnetic dephasing rate in the context of\nrecent experiments.", "We have conducted a high-resolution ``3D'' imaging survey of the CO(1--0),\nHCN(1--0), and HCO$^+$(1--0) lines toward the central a few kpc regions of the\nSeyfert and starburst galaxies in the local universe using the Nobeyama\nMillimeter Array. We detected luminous HCN(1--0) emissions toward a\nconsiderable fraction of these Seyfert galaxies (10 of 12 in our sub-sample),\nwhich indicated that some of these Seyfert galaxies, such as NGC 3079, NGC\n3227, NGC 4051, NGC 6764, and NGC 7479, are indeed accompanied with compact\nnuclear starburst, given the tight correlation between the HCN(1--0) luminosity\nand the star formation rate among star-forming galaxies. However, we suggest\nthat the elevated HCN(1--0) emission from some of these Seyfert galaxies,\nincluding NGC 1068, NGC 1097, NGC 5033, and NGC 5194, does not signify the\npresence of massive starbursts there. This is because these Seyfert nuclei show\nabnormally high HCN(1--0)/HCO$^+$(1--0) ratios (2--3), which were never\nobserved in the starburst nuclei in our sample. This could be attributed to the\noverabundance of HCN molecules in the X-ray dominated regions (XDRs) at the\ncenters of these Seyfert galaxies.", "We report high-resolution X-ray Absorption Near Edge Structure (XANES)\nmeasurements at the Mn K-edge as a function of temperature, for\nLa$_{1-x}$Ca$_x$MnO$_3$ samples, with a focus mainly on the pre-edge region.\nSmall peaks labeled A$_1$-A$_3$ are observed which corresponds to 1s-3d\ndipole-transitions, made weakly allowed via a hybridization of Mn 4p states\nwith Mn 3d states on {\\it neighboring} atoms. Adjusting the parameters in an\nLSDA calculation to approximately match the experimental A$_1$-A$_2$ splitting\nyields U = 4 eV and J$_H$ = 0.7 eV. For colossal magnetoresistance samples,\nA$_1$ decreases with T while A$_2$ increases with T below T$_c$, which shows\nthat the 3d bands change significant as T moves through T$_c$. There are also\nsmall changes in the shape of the main edge (1s-4p transitions).", "We propose a method for generating and controlling a spatially separated\nvortex--antivortex pair in a Bose-Einstein condensate trapped in a toroidal\npotential. Our simulations of the time dependent Gross-Pitaevskii equation show\nthat in toroidal condensates vortex dynamics are different from the dynamics in\nthe homogeneous case. Our numerical results agree well with analytical\ncalculations using the image method. Our proposal offers an effective example\nof coherent generation and control of vortex dynamics in atomic condensates.", "Codes to compute mean opacities and radiative accelerations for arbitrary\nchemical mixtures using the Opacity Project recently revised data have been\nrestructured in a client--server architecture and transcribed as a subroutine\nlibrary. This implementation increases efficiency in stellar modelling where\nelement stratification due to diffusion processes is depth dependent, and thus\nrequires repeated fast opacity reestimates. Three user modes are provided to\nfit different computing environments, namely a web browser, a local workstation\nand a distributed grid.", "We introduce a simple model of economy, where the time evolution is described\nby an equation capturing both exchange between individuals and random\nspeculative trading, in such a way that the fundamental symmetry of the economy\nunder an arbitrary change of monetary units is insured. We investigate a\nmean-field limit of this equation and show that the distribution of wealth is\nof the Pareto (power-law) type. The Pareto behaviour of the tails of this\ndistribution appears to be robust for finite range models, as shown using both\na mapping to the random `directed polymer' problem, as well as numerical\nsimulations. In this context, a transition between an economy dominated by a\nfew individuals from a situation where the wealth is more evenly spread out, is\nfound. An interesting outcome is that the distribution of wealth tends to be\nvery broadly distributed when exchanges are limited, either in amplitude or\ntopologically. Favoring exchanges (and, less surprisingly, increasing taxes)\nseems to be an efficient way to reduce inequalities.", "An extended Bose-Einstein condensate (BEC) in an optical lattice provides a\nkind of periodic dielectric and causes band gaps to occur in the spectrum of\nlight propagating through it. We examine the question whether these band gaps\ncan modify the spontaneous emission rate of atoms excited from the BEC, and\nwhether they can lead to a self-stabilization of the BEC against spontaneous\nemission. We find that self-stabilization is not possible for BECs with a\ndensity in the order of $10^{14}$ cm$^{-3}$. However, the corresponding\nnon-Markovian behavior produces significant effects in the decay of excited\natoms even for a homogeneous BEC interacting with a weak laser beam. These\neffects are caused by the occurrence of an avoided crossing in the photon (or\nrather polariton) spectrum. We also predict a new channel for spontaneous decay\nwhich arises from an interference between periodically excited atoms and\nperiodic photon modes. This new channel should also occur in ordinary periodic\ndielectrics.", "We compare dynamical and energetical stability criteria for vortex rings. It\nis argued that vortex rings will be intrinsically unstable against\nperturbations with short wavelengths below a critical wavelength, because the\ncanonical vortex Hamiltonian is unbounded from below for these modes. To\nexplicitly demonstrate this behaviour, we derive the oscillation spectrum of\nvortex rings in incompressible, inviscid fluids, within a geometrical cutoff\nprocedure for the core. The spectrum develops an anomalous branch of negative\ngroup velocity, and approaches the zero of energy for wavelengths which are\nabout six times the core diameter. We show the consequences of this dispersion\nrelation for the thermodynamics of vortex rings in superfluid $^4$He at low\ntemperatures.", "The gas of interacting excitons in quantum wells is studied. We obtain the\nHamiltonian of this gas by the projection of the electron-hole plasma\nHamiltonian to exciton states and an expansion in a small density. Matrix\nelements of the exciton Hamiltonian are rather sensitive to the geometry of the\nheterostructure. The mean field approximation of the exciton Hamiltonian gives\nthe blue shift and spin splitting of the exciton luminescence lines. We also\nwrite down the Boltzmann equation for excitons and estimate the energy and spin\nrelaxation time resulting from the exciton-exciton scattering. Making use of\nthese calculations we succeeded to explain some recent experimental results\nwhich have not been explained so far.", "Ground state properties and phonon dispersion curves of a classical linear\nchain model describing a crystal with an incommensurate phase are studied. This\nmodel is the DIFFOUR (discrete frustrated phi4) model with an extra\nfourth-order term added to it. The incommensurability in these models may arise\nif there is frustration between nearest-neighbor and next-nearest-neighbor\ninteractions. We discuss the effect of the additional term on the phonon\nbranches and phase diagram of the DIFFOUR model. We find some features not\npresent in the DIFFOUR model such as the renormalization of the\nnearest-neighbor coupling. Furthermore the ratio between the slopes of the soft\nphonon mode in the ferroelectric and paraelectric phase can take on values\ndifferent from -2. Temperature dependences of the parameters in the model are\ndifferent above and below the paraelectric transition, in contrast with the\nassumptions made in Landau theory. In the continuum limit this model reduces to\nthe Landau free energy expansion for type II incommensurate crystals and it can\nbe seen as the lowest-order generalization of the simplest Lifshitz-point\nmodel. Part of the numerical calculations have been done by an adaption of the\nEffective Potential Method, orginally used for models with nearest-neighbor\ninteraction, to models with also next-nearest-neighbor interactions.", "We present a study of a microtwinned single crystal of LaMnO$_3$ by means of\nimplanted muons. Two muon stopping sites are identified from the symmetry of\nthe internal field in the ordered phase. The temperature dependence of these\nfields yields the behavior of the staggered magnetization from which a static\ncritical exponent ($\\beta=0.36(2)$) is extracted and discussed. The muon\nspin-spin relaxation rate shows a critical slowing down (contrary to\npreliminary findings) with a critical exponent $n=0.7(1)$, witnessing the Ising\nnature of the dynamic fluctuations. The muon precession frequencies vs. applied\nmagnetic field reveal the saturation of the weak ferromagnetic domain structure\noriginated by the Dzialoshinski-Moriya antisymmetric exchange.", "A simple model of a glass former fluid, consisting of a bidisperse mixture of\npenetrable spheres is studied. The model shows a transition from fragile to\nstrong behavior as temperature is reduced. This transition is driven by the\ncompetition between the two mechanisms that contribute to diffusivity in the\nmodel: collective rearrangement of particles (responsible for the fragile\nbehavior), and individual particle motion (which gives rise to the strong\nbehavior at low temperature). We also observe a maximum of diffusivity as a\nfunction of pressure that can be interpreted within the same framework. The\nconnection between this behavior and polyamorphism is addressed.", "Context. A derivation of a generalized sqrt(epsilon)-law for nonthermal\ncollisional rates of excitation by charged perturbers is presented. Aims. Aim\nof this paper is to find a more general analytical expression for a surface\nvalue of the source function which can be used as an addtional tool for\nverification of the non-LTE radiative transfer codes. Methods. Under the impact\napproximation hypothesis, static, one-dimensional, plane-parallel atmosphere,\nconstant magnetic field of arbitrary strength and direction, two-level atom\nmodel with unpolarized lower level and stimulated emission neglected, we\nintroduce the unphysical terms into the equations of statistical equilibrium\nand solve the appropriate non-LTE integral equations. Results. We derive a new\nanalytical condition for the surface values of the source function components\nexpressed in the basis of irreducible spherical tensors.", "[Abridged] We have studied the optical spectra of 28 O- and early B-type\nstars in the Large Magellanic Cloud, 22 of which are associated with the young\nstar-forming region N11. Stellar parameters are determined using an automated\nfitting method, combining the stellar atmosphere code FASTWIND with the\ngenetic-algorithm optimisation routine PIKAIA. Results for stars in the LH9 and\nLH10 associations of N11 are consistent with a sequential star formation\nscenario, in which activity in LH9 triggered the formation of LH10. Our sample\ncontains four stars of spectral type O2, of which the hottest is found to be\n~49-54 kK (cf. ~45-46 kK for O3 stars). The masses of helium-enriched dwarfs\nand giants are systematically lower than those implied by non-rotating\nevolutionary tracks. We interpret this as evidence for efficient\nrotationally-enhanced mixing, leading to the surfacing of primary helium and to\nan increase of the stellar luminosity. This result is consistent with findings\nfor SMC stars by Mokiem et al. For bright giants and supergiants no such\nmass-discrepancy is found, implying that these stars follow tracks of modestly\n(or non-)rotating objects. Stellar mass-loss properties were found to be\nintermediate to those found in massive stars in the Galaxy and the SMC, and\ncomparisons with theoretical predictions at LMC metallicity yielded good\nagreement over the luminosity range of our targets, i.e. 5.0 < log L/L(sun) <\n6.1.", "We obtain the exact ground state and a part of the excitation spectrum in one\ndimension on a line and the exact ground state on a circle in a case where N\nparticles are interacting via nearest- and next-to-nearest neighbour\ninteractions. Further, using the exact ground-state, we establish a mapping\nbetween these N-body problems and the short-range Dyson models introduced\nrecently to model intermediate spectral statistics. Using this mapping we\ncompute the one- and two-point functions of a related many-body theory and show\nthat there is no long-range order in the thermodynamic limit. However, quite\nremarkably, we prove the existence of an off-diagonal long-range order in the\nsymmetrised version of the related many-body theory. Generalisation of the\nmodels to other root systems is also considered. Besides, we also generalize\nthe model on the full line to higher dimensions. Finally, we consider a model\nin two dimensions in which all the states exhibit novel correlations.", "We show that the ground state of an attractive Bose gas in a double well\nevolves from a coherent state to a Schrodinger Cat like state as the tunneling\nbarrier is decreased. The latter exhibits super- fragmentation as spin-1 Bose\ngas with antiferromagnetic interaction, which is caused by the same physics. We\nalso show that the fragmented condensates of attractive and repulsive Bose\ngases in double wells lead to very different interference patterns.", "We study the effect of the coronal background in the determination of the\ndiameter of EUV loops, and we analyze the suitability of the procedure followed\nin a previous paper (L\\'opez Fuentes, Klimchuk & D\\'emoulin 2006) for\ncharacterizing their expansion properties. For the analysis we create different\nsynthetic loops and we place them on real backgrounds from data obtained with\nthe Transition Region and Coronal Explorer (\\textit{TRACE}). We apply to these\nloops the same procedure followed in our previous works, and we compare the\nresults with real loop observations. We demonstrate that the procedure allows\nus to distinguish constant width loops from loops that expand appreciably with\nheight, as predicted by simple force-free field models. This holds even for\nloops near the resolution limit. The procedure can easily determine when loops\nare below resolution limit and therefore not reliably measured. We find that\nsmall-scale variations in the measured loop width are likely due to\nimperfections in the background subtraction. The greatest errors occur in\nespecially narrow loops and in places where the background is especially bright\nrelative to the loop. We stress, however, that these effects do not impact the\nability to measure large-scale variations. The result that observed loops do\nnot expand systematically with height is robust.", "We present the fourth edition of the Sloan Digital Sky Survey (SDSS) Quasar\nCatalog. The catalog contains 77,429 objects; this is an increase of over\n30,000 entries since the previous edition. The catalog consists of the objects\nin the SDSS Fifth Data Release that have luminosities larger than M_i = -22.0\n(in a cosmology with H_0 = 70 km/s/Mpc, Omega_M = 0.3, and Omega_Lambda = 0.7)\nhave at least one emission line with FWHM larger than 1000 km/s, or have\ninteresting/complex absorption features, are fainter than i=15.0, and have\nhighly reliable redshifts. The area covered by the catalog is 5740 sq. deg. The\nquasar redshifts range from 0.08 to 5.41, with a median value of 1.48; the\ncatalog includes 891 quasars at redshifts greater than four, of which 36 are at\nredshifts greater than five. Approximately half of the catalog quasars have i <\n19; nearly all have i < 21. For each object the catalog presents positions\naccurate to better than 0.2 arcsec. rms per coordinate, five-band (ugriz)\nCCD-based photometry with typical accuracy of 0.03 mag, and information on the\nmorphology and selection method. The catalog also contains basic radio,\nnear-infrared, and X-ray emission properties of the quasars, when available,\nfrom other large-area surveys. The calibrated digital spectra cover the\nwavelength region 3800--9200A at a spectral resolution of ~2000. The spectra\ncan be retrieved from the public database using the information provided in the\ncatalog. The average SDSS colors of quasars as a function of redshift, derived\nfrom the catalog entries, are presented in tabular form. Approximately 96% of\nthe objects in the catalog were discovered by the SDSS.", "We study the infrared (IR) properties of galaxies in the cluster MS 1054-03\nat z=0.83 by combining MIPS 24 micron data with spectra of more than 400\ngalaxies and a very deep K-band selected catalog. 19 IR cluster members are\nselected spectroscopically, and an additional 15 are selected by their\nphotometric redshifts. We derive the IR luminosity function of the cluster and\nfind strong evolution compared to the similar-mass Coma cluster. The best\nfitting Schechter function gives L*_{IR}=11.49 +0.30/-0.29 L_sun with a fixed\nfaint end slope, about one order of magnitude larger than that in Coma. The\nrate of evolution of the IR luminosity from Coma to MS 1054-03 is consistent\nwith that found in field galaxies, and it suggests that some internal\nmechanism, e.g., the consumption of the gas fuel, is responsible for the\ngeneral decline of the cosmic star formation rate (SFR) in different\nenvironments. The mass-normalized integrated SFR within 0.5R_200 in MS 1054-03\nalso shows evolution compared with other rich clusters at lower redshifts, but\nthe trend is less conclusive if the mass selection effect is considered. A\nnonnegligible fraction (13%) of cluster members, are forming stars actively and\nthe overdensity of IR galaxies is about 20 compared to the field. It is\nunlikely that clusters only passively accrete star forming galaxies from the\nsurrounding fields and have their star formation quenched quickly afterward;\ninstead, many cluster galaxies still have large amounts of gas, and their star\nformation may be enhanced by the interaction with the cluster.", "1 Generalities\n  2 Empirical diagnostics based on emission lines\n  3 Photoionization modelling\n  4 Pending questions\n  5 Appendix: Lists of useful lines and how to deal with them", "In this paper we present experimental results concerning the compaction of a\ngranular assembly of spheres under periodic shear deformation. The dynamic of\nthe system is slow and continuous when the amplitude of the shear is constant,\nbut exhibits rapid evolution of the volume fraction when a sudden change in\nshear amplitude is imposed. This rapid response is shown to be to be\nuncorrelated with the slow compaction process.", "We study density of states and conductivity of the doped double-exchange\nsystem, treating interaction of charge carriers both with the localized spins\nand with the impurities in the coherent potential approximation. It is shown\nthat under appropriate conditions there is a gap between the conduction band\nand the impurity band in paramagnetic phase, while the density of states is\ngapless in ferromagnetic phase. This can explain metal-insulator transition\nfrequently observed in manganites and magnetic semiconductors. Activated\nconductivity in the insulator phase is numerically calculated.", "We conducted extensive numerical experiments of equal mass three-body systems\nuntil they became disrupted. The system lifetimes, as a bound triple, and the\nLyapunov times show a correlation similarto what has been earlier obtained for\nsmall bodies in the Solar System. Numerical integrations of several sets of\ndifferently randomised initial conditions produced the same relationship of the\ninstability time and Lyapunov time. Marginal probability densities of the\nvarious times in the three-body experiments are also discussed. Our high\naccuracy numerical method for three-body orbit computations and Lyapunov time\ndeterminations is concisely described.", "AIM: We have recently developed a microscopic Monte Carlo approach to study\nsurface chemistry on interstellar grains and the morphology of ice mantles. The\nmethod is designed to eliminate the problems inherent in the rate-equation\nformalism to surface chemistry. Here we report the first use of this method in\na chemical model of cold interstellar cloud cores that includes both gas-phase\nand surface chemistry. The surface chemical network consists of a small number\nof diffusive reactions that can produce molecular oxygen, water, carbon\ndioxide, formaldehyde, methanol and assorted radicals. METHOD: The simulation\nis started by running a gas-phase model including accretion onto grains but no\nsurface chemistry or evaporation. The starting surface consists of either flat\nor rough olivine. We introduce the surface chemistry of the three species H, O\nand CO in an iterative manner using our stochastic technique. Under the\nconditions of the simulation, only atomic hydrogen can evaporate to a\nsignificant extent. Although it has little effect on other gas-phase species,\nthe evaporation of atomic hydrogen changes its gas-phase abundance, which in\nturn changes the flux of atomic hydrogen onto grains. The effect on the surface\nchemistry is treated until convergence occurs. We neglect all non-thermal\ndesorptive processes. RESULTS: We determine the mantle abundances of assorted\nmolecules as a function of time through 2x10^5 yr. Our method also allows\ndetermination of the abundance of each molecule in specific monolayers. The\nmantle results can be compared with observations of water, carbon dioxide,\ncarbon monoxide, and methanol ices in the sources W33A and Elias 16. Other than\na slight underproduction of mantle CO, our results are in very good agreement\nwith observations.", "A review is given of recent theoretical work on the superfluid dynamics of\ntrapped Bose gases at finite temperatures, where there is a significant\nfraction of non-condensate atoms. One can now reach large enough densities and\ncollision cross-sections needed to probe the collective modes in the\ncollision-dominated hydrodynamic region where the gas exhibits characteristic\nsuperfluid behavior involving the relative motions of the condensate and\nnon-condensate components. The precise analogue of the Landau-Khalatnikov\ntwo-fluid hydrodynamic equations was recently derived from trapped Bose gases,\nstarting from a generalized Gross-Pitaevskii equation for the condensate\nmacroscopic wavefunction and a kinetic equation for the non-condensate atoms.", "We consider the extent to which future imaging surveys of galaxies can\ndistinguish between dark energy and modified gravity models for the origin of\nthe cosmic acceleration. Dynamical dark energy models may have similar\nexpansion rates as models of modified gravity, yet predict different growth of\nstructure histories. We parameterize the cosmic expansion by the two\nparameters, $w_0$ and $w_a$, and the linear growth rate of density fluctuations\nby Linder's $\\gamma$, independently. Dark energy models generically predict\n$\\gamma \\approx 0.55$, while the DGP model $\\gamma \\approx 0.68$. To determine\nif future imaging surveys can constrain $\\gamma$ within 20 percent (or\n$\\Delta\\gamma<0.1$), we perform the Fisher matrix analysis for a weak lensing\nsurvey such as the on-going Hyper Suprime-Cam (HSC) project. Under the\ncondition that the total observation time is fixed, we compute the Figure of\nMerit (FoM) as a function of the exposure time $\\texp$. We find that the\ntomography technique effectively improves the FoM, which has a broad peak\naround $\\texp\\simeq {\\rm several}\\sim 10$ minutes; a shallow and wide survey is\npreferred to constrain the $\\gamma$ parameter. While $\\Delta\\gamma < 0.1$\ncannot be achieved by the HSC weak-lensing survey alone, one can improve the\nconstraints by combining with a follow-up spectroscopic survey like WFMOS\nand/or future CMB observations.", "We report the first experimental evidence for a metallic phase in fluid\nmolecular oxygen. Our electrical conductivity measurements of fluid oxygen\nunder dynamic quasi-isentropic compression show that a non-metal/metal\ntransition occurs at 3.4 fold compression, 4500 K and 1.2 Mbar. We discuss the\nmain features of the electrical conductivity dependence on density and\ntemperature and give an interpretation of the nature of the electrical\ntransport mechanisms in fluid oxygen at these extreme conditions.", "We propose a new `hedged' Monte-Carlo (HMC) method to price financial\nderivatives, which allows to determine simultaneously the optimal hedge. The\ninclusion of the optimal hedging strategy allows one to reduce the financial\nrisk associated with option trading, and for the very same reason reduces\nconsiderably the variance of our HMC scheme as compared to previous methods.\nThe explicit accounting of the hedging cost naturally converts the objective\nprobability into the `risk-neutral' one. This allows a consistent use of purely\nhistorical time series to price derivatives and obtain their residual risk. The\nmethod can be used to price a large class of exotic options, including those\nwith path dependent and early exercise features.", "We have used the Very Large Array (VLA) to search for radio emission from the\nglobular cluster G1 (Mayall-II) in M31. G1 has been reported by Gebhardt et al.\nto contain an intermediate-mass black hole (IMBH) with a mass of ~2 x 10^4\nsolar masses. Radio emission was detected within an arcsecond of the cluster\ncenter with an 8.4 GHz power of 2 x 10^{15} W/Hz. The radio/X-ray ratio of G1\nis a few hundred times higher than that expected for a high-mass X-ray binary\nin the cluster center, but is consistent with the expected value for accretion\nonto an IMBH with the reported mass. A pulsar wind nebula is also a possible\ncandidate for the radio and X-ray emission from G1; future high-sensitivity\nVLBI observations might distinguish between this possibility and an IMBH. If\nthe radio source is an IMBH, and similar accretion and outflow processes occur\nfor hypothesized ~ 1000-solar-mass black holes in Milky Way globular clusters,\nthey are within reach of the current VLA and should be detectable easily by the\nExpanded VLA when it comes on line in 2010.", "In the past decade high resolution measurements in the infrared employing\nadaptive optics imaging on 10m telescopes have allowed determining the three\ndimensional orbits stars within ten light hours of the compact radio source at\nthe center of the Milky Way. These observations show the presence of a three\nmillion solar mass black hole in Sagittarius A* beyond any reasonable doubt.\nThe Galactic Center thus constitutes the best astrophysical evidence for the\nexistence of black holes which have long been postulated, and is also an ideal\n`lab' for studying the physics in the vicinity of such an object. Remarkably,\nyoung massive stars are present there and probably have formed in the innermost\nstellar cusp. Variable infrared and X-ray emission from Sagittarius A* are a\nnew probe of the physical processes and space-time curvature just outside the\nevent horizon.", "The theory of fluctuation conductivity for an arbitrary impurity\nconcentration including ultra-clean limit is developed. It is demonstrated that\nthe formal divergency of the fluctuation density of states contribution\nobtained previously for the clean case is removed by the correct treatment of\nthe non-local ballistic electron scattering. We show that in the ultra-clean\nlimit ($T\\tau \\gg \\sqrt{\\frac{T_c}{T-T_c}}$) the density-of-states quantum\ncorrections are canceled by the Maki-Thompson term and only quasi-classical\nparaconductivity remains.", "The phase diagram of an incompressible fluid membrane subject to quantum and\nthermal fluctuations is calculated exactly in a large number of dimensions of\nconfiguration space. At zero temperature, a crumpling transition is found at a\ncritical bending rigidity $1/\\alpha_{\\rm c}$. For membranes of fixed lateral\nsize, a crumpling transition occurs at nonzero temperatures in an auxiliary\nmean field approximation. As the lateral size L of the membrane becomes large,\nthe flat regime shrinks with $1/\\ln L$.", "While the members of the Type IIn category of supernovae are united by the\npresence of strong multicomponent Balmer emission lines in their spectra, they\nare quite heterogeneous with respect to other properties such as Balmer line\nprofiles, light curves, strength of radio emission, and intrinsic brightness.\nWe are now beginning to see variety among SNe IIn in their polarimetric\ncharacteristics as well, some but not all of which may be due to inclination\nangle effects. The increasing number of known \"hybrid\" SNe with IIn-like\nemission lines suggests that circumstellar material may be more common around\nall types of SNe than previously thought. Investigation of the correlations\nbetween spectropolarimetric signatures and other IIn attributes will help us\naddress the question of classification of \"interacting SNe\" and the possibility\nof distinguishing different groups within the diverse IIn subclass.", "We provide a grid of PHOENIX spectra of red giant and supergiant stars, that\nextend through optical and near-IR wavelengths. For the first time, models are\nalso provided with modified surface abundances of C, N and O, as a step towards\naccounting for the changes known to occur due to convective dredge-up (and to\nbe enhanced in the case of rotation). The aims are (i) to assess how well\ncurrent models reproduce observed spectra, (ii) to quantify the effects of the\nabundance changes on the spectra, and (iii) to determine how these changes\naffect estimates of fundamental stellar parameters.\n  Observed giant star spectra can be fitted very well at solar metallicity down\nto about 3400K. Modified surface abundances are preferred in only a minority of\ncases for luminosity class II, possibly indicating mixing in excess of standard\nfirst dredge-up.\n  Supergiant stars show a larger variety of near-IR spectra, and good fits are\ncurrently obtained for about one third of the observations only. Modified\nsurface abundances help reproducing strong CN bands, but do not suffice to\nresolve all the difficulties. The effect of the abundance changes on the\nestimated Teff depends on the wavelength range of observation and can amount\nseveral 100K. Reasons for the remaining discrepancies are discussed.", "The diffusion Monte Carlo method is applied to describe a trapped atomic\nBose-Einstein condensate at zero temperature, fully quantum mechanically and\nnonperturbatively. For low densities, $n(0)a^3 \\le 2 \\cdot 10^{-3}$ [n(0): peak\ndensity, a: s-wave scattering length], our calculations confirm that the exact\nground state energy for a sum of two-body interactions depends on only the\natomic physics parameter a, and no other details of the two-body model\npotential. Corrections to the mean-field Gross-Pitaevskii energy range from\nbeing essentially negligible to about 20% for N=2-50 particles in the trap with\npositive s-wave scattering length a=100-10000 a.u.. Our numerical calculations\nconfirm that inclusion of an additional effective potential term in the\nmean-field equation, which accounts for quantum fluctuations [see e.g. E.\nBraaten and A. Nieto, Phys. Rev. B 56}, 14745 (1997)], leads to a greatly\nimproved description of trapped Bose gases.", "In this paper we consider stationary force-free magnetosphere of an aligned\nrotator when plasma in the open field line region rotates differentially due to\npresence of a zone with the accelerating electric field in the polar cap of\npulsar. We study the impact of differential rotation on the current density\ndistribution in the magnetosphere. Using split-monopole approximation we obtain\nanalytical expressions for physical parameters of differentially rotating\nmagnetosphere. We find the range of admitted current density distributions\nunder the requirement that the potential drop in the polar cap is less than the\nvacuum potential drop. We show that the current density distribution could\ndeviate significantly from the ``classical'' Michel distribution and could be\nmade almost constant over the polar cap even when the potential drop in the\naccelerating zone is of the order of 10 per cents of the vacuum potential drop.\nWe argue that differential rotation of the open magnetic field lines could play\nan important role in adjusting between the magnetosphere and the polar cap\ncascade zone and could affect the value of pulsar breaking index.", "The analysis of images (of obtained in various ranges of the lengths of\nwaves) of luminous objects in the Universe by means of a method of multilevel\ndynamic contrasting led author to the conclusions: a) the structures of all\nobservable galaxies represents a complicated constructions which have the\ntendency to self-similarity and made of separate (basic) blocks, which are a\ncoaxially tubular structures and a cartwheel-like structures; b) the majority\nof observable objects in the Universe are luminous butt-ends of almost\ninvisible (of almost completely transparent) of filamentary formations which\nstructures are seen only near to their luminous butt-ends; c) the result of\nanalysis of images of cosmic objects show the structure of many pairs of\ncooperating galaxies point to opportunity of their formation at butt-ends\ngenerated in a place of break of the similar filament; d) the interacting\ngalaxies (M 81 and M 82) show they are butt-ends of sawed off of two branches\nof a treelike filament and their interaction is coming out through this\nfilament; e) as our Universe is in dynamics the processes of formation of\nstars, galaxies and their congestions can go presently by means of a fracturing\nof filaments with a corresponding diameters and of the time for their such\nformation is necessary much less, than along existing standard model.", "We report the results of spectroscopic mapping observations carried out\ntoward small (1 x 1 arcmin) regions within the supernova remnants W44, W28,\nIC443, and 3C391 using the Infrared Spectrograph of the Spitzer Space\nTelescope. These observations, covering the 5.2 - 37 micron spectral region,\nhave led to the detection of a total of 15 fine structure transitions of Ne+,\nNe++, Si+, P+, S, S++, Cl+, Fe+, and Fe++; the S(0) - S(7) pure rotational\nlines of molecular hydrogen; and the R(3) and R(4) transitions of hydrogen\ndeuteride. In addition to these 25 spectral lines, the 6.2, 7.7, 8.6, 11.3 and\n12.6 micron PAH emission bands were also observed. Most of the detected line\ntransitions have proven strong enough to map in several sources, providing a\ncomprehensive picture of the relative distribution of the various line\nemissions observable in the Spitzer/IRS bandpass. A principal component\nanalysis of the spectral line maps reveals that the observed emission lines\nfall into five distinct groups, each of which may exhibit a distinct spatial\ndistribution: (1) lines of S and H2 (J > 2); (2) the H2 S(0) line; (3) lines of\nions with appearance potentials less than 13.6 eV; (4) lines of ions with\nappearance potentials greater than 13.6 eV, not including S++; (5) lines of\nS++. Lines of group (1) likely originate in molecular material subject to a\nslow, nondissociative shock that is driven by the overpressure within the\nsupernova remnant, and lines in groups (3) - (5) are associated primarily with\ndissociative shock fronts with a range of (larger) shock velocities. The H2\nS(0) line shows a low-density diffuse emission component, and - in some sources\n- a shock-excited component.", "A new XMM observation has made possible a detailed study of both lobes of the\nradio galaxy Pictor A. Their X-ray emission is of non thermal origin and due to\nInverse Compton scattering of the microwave background photons by relativistic\nelectrons in the lobes, as previously found. In both lobes, the equipartition\nmagnetic field (Beq) is bigger than the Inverse Compton value (Bic), calculated\nfrom the radio and X-ray flux ratio. The Beq/Bic ratio never gets below 2, in\nspite of the large number of reasonable assumptions tested to calculate Beq,\nsuggesting a lobe energetic dominated by particles. The X-ray data quality is\ngood enough to allow a spatially resolved analysis. Our study shows that Bic\nvaries through the lobes. It appears to increase behind the hot spots. On the\ncontrary, a rather uniform distribution of the particles is observed. As a\nconsequence, the radio flux density variation along the lobes appears to be\nmainly driven by magnetic field changes.", "It is pointed out that first, contrary to the claim by Baym et al.[Phys. Rev.\nLett 83, 1703 (1999)], the shift in the transition temperature of a weakly\ninteracting Bose gas can be calculated perturbatively. And second, that the\nregime considered by Huang [Phys. Rev. Lett 83, 3770 (1999)] while addressing\nthe same issue does not describe the Bose-Einstein condensed phase.", "We present a comparative study of the magnetic, transport and structural\nproperties of $Nd_{0.5}Ca_{0.5}MnO_{3+\\delta}$ [$\\delta=$ 0.02(1) and 0.04(1)].\nWe have found significant differences between the low temperature magnetic\norders and the magnetization curves below $T_{CO}\\approx 250 K$ of the two\nsamples. In particular one component of the magnetic moment presents a\nferromagnetic coupling between the $(0 0 1)$ planes ($P bnm$ setting) deviating\nthe angle between neighboring $Mn$ ions from $180^o$ (perfect CE order) to\n$150^o$ [$\\delta=0.02(1)$] and $130^o$ [$\\delta= 0.04(1)$]. These results imply\na remarkable $\\delta$ dependence which is discussed in the light of a\nnon-random spatial distribution of defects in the perfect charge order scheme.", "Distances to well-observed Type II-P SNe are determined from an updated\nversion of the Expanding Photosphere Method (EPM), based on recent theoretical\nmodels. The new EPM distances show good agreement with other independent\ndistances to the host galaxies without any significant systematic bias,\ncontrary to earlier results in the literature. The accuracy of the method is\ncomparable with that of the distance measurements for Type Ia SNe.", "Underdoped high-Tc superconductors are frequently characterised by a\ntemperature, T*, below which the normal-state pseudogap opens. Two different\n\"phase diagrams\" based on the doping (p) dependence of T* are currently\nconsidered: one where T* falls to zero at a critical doping state and the other\nwhere T* merges with Tc in the overdoped region. By examining the temperature\ndependence of the NMR Knight shift and relaxation rate, entropy, resistivity,\ninfrared conductivity, Raman scattering, ARPES and tunnelling data it is\nconcluded that the second scenario is not at all supported. Neither can one\ndistinguish a small and a large pseudogap as is often done. T* is an energy\nscale which falls abruptly to zero at p=0.19.", "Doping of a two-orbital chain with mobile S=1/2 Fermions and strong Hund's\nrule couplings stabilizing the S=1 spins strongly depends on the presence of a\nlevel difference among these orbitals. By DMRG methods we find a finite spin\ngap upon doping and dominant pairing correlations without level-difference,\nwhereas the presence of a level difference leads to dominant charge density\nwave (CDW) correlations with gapless spin-excitations. The string correlation\nfunction also shows qualitative differences between the two models.", "Multiwavelength observations are reported here of the Be/X-ray binary pulsar\nsystem GRO J1008-57. Over ten years worth of data are gathered together to show\nthat the periodic X-ray outbursts are dependant on both the binary motion and\nthe size of the circumstellar disk. In the first instance an accurate orbital\nsolution is determined from pulse periods, and in the second case the strength\nand shape of the Halpha emission line is shown to be a valuable indicator of\ndisk size and its behaviour. Furthermore, the shape of the emission line\npermits a direct determination of the disk size which is in good agreement with\ntheoretical estimates. A detailed study of the pulse period variations during\noutbursts determined the binary period to be 247.8, in good agreement with the\nperiod determined from the recurrence of the outbursts.", "We study the consequences of introducing quantum group invariance in the\nformalism of nonextensive quantum statistical mechanics.\n  We find that the corresponding thermodynamical system is equivalent to a\nBose-Einstein gas in the Boltzmann-Gibbs formalism with a higher critical\ntemperature than the standard Bose-Einstein case.", "A strong anti-correlation between ionization and scintillation signals\nproduced by MeV gamma-rays in liquid xenon has been measured and used to\nimprove the energy resolution by combining the two signals. The improvement is\nexplained by reduced electron-ion recombination fluctuations of the combined\nsignal compared to fluctuations of the individual signals. Simultaneous\nmeasurements of ionization and scintillation signals were carried out with\nCs-137, Na-22 and Co-60 gamma rays, as a function of electric field in the\nliquid. A resolution of 1.7%(sigma) at 662 keV was measured at 1 kV/cm,\nsignificantly better than the resolution from either scintillation or\nionization alone. A detailed analysis indicates that further improvement to\nless than 1%(sigma) is possible with higher light collection efficiency and\nlower electronic noise.", "We study the spectrum of rotating Bose-Einstein Condensates in the limit of\nweak repulsive interactions and present analytical and numerical results for\nenergies and wave functions. While the low-lying states are of collective\nnature, the high-lying states are dominated by single-particle excitations and\ncan accurately approximated by simple polynomial expressions. In the limit that\nthe number of particles is large compared to the number of excited quanta, the\nsingle-particle states become excellent approximations to the eigenstates, and\na rather simple ordering scheme is obtained.", "IGR J11215-5952 is a hard X-ray transient source discovered in April 2005\nwith INTEGRAL and a confirmed member of the new class of High Mass X-ray\nBinaries, the Supergiant Fast X-ray Transients (SFXTs). Archival INTEGRAL data\nand RXTE observations showed that the outbursts occur with a periodicity of\n~330 days. Thus, IGR J11215-5952 is the first SFXT displaying periodic\noutbursts, possibly related to the orbital period. We performed a Target of\nOpportunity observation with Swift with the main aim of monitoring the source\nbehaviour around the time of the fifth outburst, expected on 2007 Feb 9. The\nsource field was observed with Swift twice a day (2ks/day) starting from 4th\nFebruary, 2007, until the fifth outburst, and then for ~5 ks a day afterwards,\nduring a monitoring campaign that lasted 23 days for a total on-source exposure\nof ~73 ks. This is the most complete monitoring campaign of an outburst from a\nSFXT. The spectrum during the brightest flares is well described by an absorbed\npower law with a photon index of 1 and N_H~1 10^22 cm^-2. A 1-10 keV peak\nluminosity of ~10^36 erg s^-1 was derived (assuming 6.2 kpc, the distance of\nthe optical counterpart). These Swift observations are a unique data-set for an\noutburst of a SFXT, thanks to the combination of sensitivity and time coverage,\nand they allowed a study of IGR J11215-5952 from outburst onset to almost\nquiescence. We find that the accretion phase lasts longer than previously\nthought on the basis of lower sensitivity instruments observing only the\nbrightest flares. The observed phenomenology is consistent with a smoothly\nincreasing flux triggered at the periastron passage in a wide eccentric orbit\nwith many flares superimposed, possibly due to episodic or inhomogeneous\naccretion.", "The gravitational wave signal arising from the collapsing iron core of a Type\nII supernova progenitor star carries with it the imprint of the progenitor's\nmass, rotation rate, degree of differential rotation, and the bounce depth.\nHere, we show how to infer the gravitational radiation waveform of a core\ncollapse event from noisy observations in a network of two or more LIGO-like\ngravitational wave detectors and, from the recovered signal, constrain these\nsource properties. Using these techniques, predictions from recent core\ncollapse modeling efforts, and the LIGO performance during its S4 science run,\nwe also show that gravitational wave observations by LIGO might have been\nsufficient to provide reasonable estimates of the progenitor mass, angular\nmomentum and differential angular momentum, and depth of the core at bounce,\nfor a rotating core collapse event at a distance of a few kpc.", "Using Hartree-Fock orbitals with residual Coulomb repulsion, we study\nspinless fermions in a two dimensional random potential. When we increase the\nsystem size $L$ at fixed particle density, the size dependence of the average\ninverse compressibility exhibits a smooth crossover from a $1/L^2$ towards a\n1/L decay when the Coulomb energy to Fermi energy ratio $r_s$ increases from 0\nto 3. In contrast, the distribution of the first energy excitation displays a\nsharp Poisson-Wigner-like transition at $r_s \\approx 1$.", "In this paper we would like give a short review of our recent works and\ncurrent investigation in modeling of solid film surfaces growth based on\ncomputer Monte\n  Carlo simulations. We also discuss effect of some simplification in growth\nrules on speed-up of computations, and the time evolution of surface morphology\n(for example its roughness or anisotropy). We obtained qualitative agreement of\ncomputer simulation with experimental results for homoepitaxially grown simple\nmetal films.", "The Coulomb gap in a donor-acceptor model with finite charge transfer energy\n$\\Delta$ describing the electronic system on the dielectric side of the\nmetal-insulator transition is investigated by means of computer simulations on\ntwo- and three-dimensional finite samples with a random distribution of equal\namounts of donor and acceptor sites. Rigorous relations reflecting the symmetry\nof the model presented with respect to the exchange of donors and acceptors are\nderived. In the immediate neighborhood of the Fermi energy $\\mu$ the the\ndensity of one-electron excitations $g(\\epsilon)$ is determined solely by\nfinite size effects and $g(\\epsilon)$ further away from $\\mu$ is described by\nan asymmetric power law with a non-universal exponent, depending on the\nparameter $\\Delta$.", "The insulator-metal transition in single crystal La(5/8-y)Pr(y)Ca(3/8)MnO3\nwith y=0.35 was studied using synchrotron x-ray diffraction, electric\nresistivity, magnetic susceptibility, and specific heat measurements. Despite\nthe dramatic drop in the resistivity at the insulator-metal transition\ntemperature Tmi, the charge-ordering (CO) peaks exhibit no anomaly at this\ntemperature and continue to grow below Tmi. Our data suggest then, that in\naddition to the CO phase, another insulating phase is present below Tco. In\nthis picture, the insulator-metal transition is due to the changes within this\nlatter phase. The CO phase does not appear to play a major role in this\ntransition. We propose that a percolation-like insulator-metal transition\noccurs via the growth of ferromagnetic metallic domains within the parts of the\nsample that do not exhibit charge ordering. Finally, we find that the\nlow-temperature phase-separated state is unstable against x-ray irradiation,\nwhich destroys the CO phase at low temperatures.", "We present a Spitzer based census of the IC 348 nebula and embedded star\ncluster. Our Spitzer census supplemented by ground based spectra has added 42\nclass II T-Tauri sources to the cluster membership and identified ~20 class 0/I\nprotostars. The population of IC 348 likely exceeds 400 sources after\naccounting statistically for unidentified diskless members. Our Spitzer census\nof IC 348 reveals a population of protostars that is anti-correlated spatially\nwith the T-Tauri members, which comprise the centrally condensed cluster around\na B star. The protostars are instead found mostly at the cluster periphery\nabout 1 pc from the B star and spread out along a filamentary ridge. We find\nthat the star formation rate in this protostellar ridge is consistent with that\nrate which built the exposed cluster while the presence of fifteen cold,\nstarless, millimeter cores intermingled with this protostellar population\nindicates that the IC 348 nebula has yet to finish forming stars. We show that\nthe IC 348 cluster is of order 3-5 crossing times old, and, as evidenced by its\nsmooth radial profile and confirmed mass segregation, is likely relaxed. While\nit seems apparent that the current cluster configuration is the result of\ndynamical evolution and its primordial structure has been erased, our findings\nsupport a model where embedded clusters are built up from numerous smaller\nsub-clusters. Finally, the results of our Spitzer census indicate that the\nsupposition that star formation must progress rapidly in a dark cloud should\nnot preclude these observations that show it can be relatively long lived.", "1% $^{119}$Sn-doped La$_{0.5}$Ca$_{0.5}$MnO$_3$ was studied by M\\\"ossbauer\nspectroscopy, magnetic moment and resistivity measurements. The M\\\"ossbauer\nspectra below the charge-ordering temperature are explained with ferromagnetic\n(FM), antiferromagnetic (AF), and ferromagnetic spin cluster (CL) components.\nThe magnetic and thermal hystereses of the relative intensities of the\ncomponents observed in the M\\\"ossbauer spectra, and of the bulk properties such\nas magnetic moment and electrical resistivity, in the temperature range 125-185\nK, are characteristic of phase equilibrium in a first-order transition, i.e. of\nphase separation in the system below the charge-ordering (CO) transition. The\ncluster component displays a significant hyperfine field up to $\\sim 125$ K.\nAbove this temperature it exhibits superparamagnetism, becoming the dominant\ncomponent above the charge-ordering transition. These results are discussed in\nthe framework of recent investigations of the manganite system with other\ntechniques which also show phase separation.", "We report the first detection of the 6.2micron and 7.7micron infrared `PAH'\nemission features in the spectrum of a high redshift QSO, from the Spitzer-IRS\nspectrum of the Cloverleaf lensed QSO (H1413+117, z~2.56). The ratio of PAH\nfeatures and rest frame far-infrared emission is the same as in lower\nluminosity star forming ultraluminous infrared galaxies and in local PG QSOs,\nsupporting a predominantly starburst nature of the Cloverleaf's huge\nfar-infrared luminosity (5.4E12 Lsun, corrected for lensing). The Cloverleaf's\nperiod of dominant QSO activity (Lbol ~ 7E13 Lsun) is coincident with an\nintense (star formation rate ~1000 Msun/yr) and short (gas exhaustion time\n~3E7yr) star forming event.", "We investigate the excited stationary states of Bose-Einstein condensates\ntrapped in harmonic potentials. We derive simple analytical approximations of\nthe first few eigenstates of the associated time-independent one-dimensional\nGross-Pitaevskii equation and their energies. Our results are excited state\ngeneralizations of the Thomas-Fermi approximation of the ground state.", "We report a detection of the 9.7 micrometer silicate absorption feature in a\ndamped Lyman-alpha (DLA) system at z_{abs} = 0.524 toward AO0235+164, using the\nInfrared Spectrograph (IRS) onboard the Spitzer Space Telescope. The feature\nshows a broad shallow profile over about 8-12 micrometers in the absorber rest\nframe and appears to be > 15 sigma significant in equivalent width. The feature\nis fit reasonably well by the silicate absorption profiles for laboratory\namorphous olivine or diffuse Galactic interstellar clouds. To our knowledge,\nthis is the first indication of 9.7 micrometer silicate absorption in a DLA. We\ndiscuss potential implications of this finding for the nature of the dust in\nquasar absorbers. Although the feature is relatively shallow (tau_{9.7} =\n0.08-0.09), it is about 2 times deeper than expected from extrapolation of the\ntau_{9.7} vs. E(B-V) relation known for diffuse Galactic interstellar clouds.\nFurther studies of the 9.7 micrometer silicate feature in quasar absorbers will\nopen a new window on the dust in distant galaxies.", "Near to filling fraction $\\nu=1$, the quantum Hall ferromagnet contains\nmultiple Skyrmion spin excitations. This multi-Skyrmion system has a\ntremendously rich quantum-critical structure. This is simplified when Skyrmions\nare pinned by disorder. We calculate the nuclear relaxation rate in this case\nand compare the result with experiment. We discus how such measurements may be\nused to further probe the quantum-critical structure of the multi-Skyrmion\nsystem.", "Long Gamma Ray Bursts hold the promise of probing star-formation and metal\nenrichment up to very high redshifts. The present GRB samples with redshift\ndetermination are largely incomplete and therefore a careful analysis of\nselection effects is mandatory before any conclusion can be drawn from the\nobserved GRB redshift distribution. We study and compare three well defined\nsamples of long GRBs detected by Swift, HETE2 and BeppoSAX. We find that Swift\nGRBs are slighly fainter and harder than BeppoSAX and HETE2 GRBs, as expected\ndue to the higher energy range in which Swift GRBs are detected and localized,\ncompared to BeppoSAX and HETE2. Gas and dust obscuration plays a role in\nshaping the GRB samples and the present samples of GRBs with redshift. We argue\nthat the majority of the bright Swift GRBs without redshift might actually be\nz<~2 events therefore the present Swift GRB sample with redshift is biased\nagainst low-z GRBs. On the other hand, the detection of bright UV rest-frame\nafterglows from high-z GRBs, and even from those with large X-ray obscuration,\nimplies a dust amount lower than in nearby GRBs,and/or a different dust\ncomposition. If this is the case, the Swift sample of GRBs with redshifts is\nprobably a fair sample of the real high-z GRB population. The absence of high-z\nGRBs in the BeppoSAX and HETE2 samples of GRBs with redshifts is probably due\nto the fact at the time of BeppoSAX and HETE2 follow-up faint afterglows of\nhigh redshift GRBs will have weaken below the spectroscopic capabilities of\neven 10m class telescopes. The redshift distribution of a subsample of Swift\nGRBs with distributions of peak-fluxes, X-ray obscuration and optical magnitude\nat a fixed observing time similar to those of the BeppoSAX and HETE2 samples,\nis roughly consistent with BeppoSAX+HETE2 redshift distribution.", "We report on some extensive analysis of a recently proposed model [A.\nLipowski Phys. Rev. E {\\bf 60}, 6255 (1999)] with infinitely many absorbing\nstates. By performing extensive Monte Carlo simulations we have determined\ncritical exponents and show strong evidence that this model is not in the\ndirected percolation universality class.\n  The conjecture that this two-dimensional model exhibits a dimensional\nreduction (behaving as one-dimensional directed percolation) is firmly\ndisproven.\n  The reason for the model not exhibiting standard directed percolation scaling\nbehavior is traced back to the existence of what we call {\\it superabsorbing\nsites}, i.e. absorbing sites that cannot be directly activated by the presence\nof neighboring activity in one or more than one directions.\n  Supporting this claim we present two strong evidences: (i) in one dimension,\nwhere superabsorbing sites do not appear at the critical point, the system\nbehaves as directed percolation, and (ii) in a modified two-dimensional\nvariation of the model, defined on a honeycomb lattice, for which\nsuperabsorbing sites are very rarely observed, directed percolation behavior is\nrecovered. Finally, a parallel updating version of the model exhibiting a\nnonequilibrium first-order transition is also reported.", "We present the results of radial velocity measurements of two samples of\nactive stars. The first sample contains field G and K giants across the Red\nGiant Branch, whereas the second sample consists of nearby young stars (d < 150\npc) with ages between 10 - 300 Myrs. The radial velocity monitoring program has\nbeen carried out with FEROS at 1.52 m ESO telescope (1999 - 2002) and continued\nsince 2003 at 2.2 m MPG/ESO telescope. We observed stellar radial velocity\nvariations which originate either from the stellar activity or the presence of\nstellar/substellar companions. By means of a bisector technique we are able to\ndistinguish the sources of the radial velocity variation. Among them we found\nfew candidates of planetary companions, both of young stars and G-K giants\nsample.", "The relation between three-dimensional lattice structure and magnetism in\ncorrelated electron systems is explored for face centered cubic (FCC), body\ncentered cubic (BCC), and simple cubic (SC) lattices. In particular, we\nquestion which lattice structure has the strongest tendency toward the\nferromagnetism or antiferromagnetism. We employ the Hubbard model to calculate\nthe spin susceptibility and the single-particle spectrum with the\nfluctuation-exchange (FLEX) and the two-particle self-consistent (TPSC)\napproximations in the weak coupling regime. We have shown that (i)\nferromagnetic spin fluctuations become dominant when the Fermi level lies\naround a sharp peak (divergence) in the density of states (D(E)) near the\nbottom of the band, which occurs for FCC with/without next nearest neighbor\nhoppings (t') or BCC with an appropriate value of t'. Among the cases studied,\nthe ferromagnetic fluctuation is found to be the strongest for FCC with a\nfinite t'. (ii) When the peak in D(E) resides around the band center as in\nbipartite SC or BCC, antiferromagnetic fluctuations become dominant when the\nband is close to the half-filling, with the fluctuation being much stronger in\nBCC.", "The ground-state energy, the effective mass and the number of virtual phonons\nof the optical large polaron confined strictly in one dimension have been\nestimated by using the generalized Gaussian approximation. The leading-order\nterms take care of all Gaussian fluctuations in the system and improve the\nconventional variational estimates at finite coupling. Particularly, the lowest\nupper bound to the polaron ground-state energy has been obtained. The\nnon-Gaussian contributions systematically correct the leading-order\napproximations. We have obtained exact analytical solutions in the weak- and\nstrong-coupling limit and reasonable numerical data for intermediate coupling.\nOur result for the number of excited phonons limits the validity region of the\nfew-phonon approximation methods.", "We study the dynamics of a generalized Minority Game (GMG) and of the Bar\nAttendance Model (BAM) in which a number of agents self-organize to match an\nattendance that is fixed externally as a control parameter. We compare the\nusual dynamics used for the Minority Game with one for the BAM that makes a\nbetter use of the available information. We study the asymptotic states reached\nin both frameworks. We show that states that can be assimilated to either\nthermodynamic equilibrium or quenched configurations can appear in both models,\nbut with different settings. We discuss the relevance of the parameter $G$ that\nmeasures the value of the prize for winning in units of the fine for losing. We\nalso provide an annealing protocol by which the quenched configurations of the\nGMG can progressively be modified to reach an asymptotic equlibrium state that\ncoincides with the one obtained with the BAM.", "We study the electron motion near magnetic field steps at which the strength\nand/or sign of the magnetic field changes. The energy spectrum for such systems\nis found and the electron states (bound and scattered) are compared with their\ncorresponding classical paths. Several classical properties as the velocity\nparallel to the edge, the oscillation frequency perpendicular to the edge and\nthe extent of the states are compared with their quantum mechanical\ncounterpart. A class of magnetic edge states is found which do not have a\nclassical counterpart.", "Counterion-mediated attractions between like-charged fluid membranes are\nlong-ranged and non-pairwise additive at high temperatures. At zero\ntemperature, however, they are pairwise additive and decay exponentially with\nthe membrane separation. Here we show that the nature of these attractions is\ndetermined by the dominant modes of fluctuations in the density of counterions.\nWhile the non-pairwise additive interactions arise from long-wavelength\nfluctuations and vanish at zero temperature, the short-ranged pairwise additive\ninteractions arise from short-wavelength fluctuations and are stronger at low\ntemperatures.", "We propose an ``interferometric'' scheme for Bose-Einstein condensates using\nnear-field diffraction. The scheme is based on the phenomenon of intermode\ntraces or quantum carpets; we show how it may be used in the detection of weak\nforces.", "The line of sight to the quasar B0218+357, one of the most studied lensed\nsystems, intercepts a z=0.68 spiral galaxy, which splits its image into two\nmain components A and B, separated by ca. 0.3'', and gives rise to molecular\nabsorption. Although the main absorption component has been shown to arise in\nfront of image A, it is not established whether some absorption from other\nvelocity components is also occuring in front of image B. To tackle this\nquestion, we have observed the HCO+(2-1) absorption line during the\ncommissioning phase of the new very extended configuration of the Plateau de\nBure Interferometer, in order to trace the position of the absorption as a\nfunction of frequency. Visibility fitting of the self-calibrated data allowed\nus to achieve position accuracy between ~12 and 80 mas per velocity component.\nOur results clearly demonstrate that all the different velocity components of\nthe HCO+(2-1) absorption arise in front of the south-west image A of the\nquasar. We estimate a flux ratio fA/fB = 4.2 (-1.0;+1.8 at 106 GHz.", "In this paper we derive out the exact solution of the SU(n) Hubbard model\nthrough the coordinate and the algebraic Bethe ansatz methods. The energy\nspectrum and the Bethe ansatz equations are obtained. Furthermore, we analysis\nthe ground state and give out the exact analytic solution of the model.", "We report measurements of thermally-induced mean-square director-angle\nfluctuations <theta^2> below primary supercritical bifurcations to\nelectroconvection of the nematic liquid crystals I52 and \"Merck Phase V\". For\nepsilon_mf = V^2/V_c,mf^2 - 1 < -0.1 (V is the amplitude of the applied\nalternating voltage) we find <theta^2> proportional to epsilon_mf^(-gamma) with\ngamma given by linear theory (LT). Closer to the bifurcation there are\ndeviations from LT with a smaller gamma and with V_c^2 > V_c,mf^2. For I52\nmeasurements as a function of the conductivity sigma of <theta^2> above V_c^2\nsuggest a tricritical bifurcation at sigma_t = 4.0 x 10^(-9) Omega^(-1)m^(-1),\nand (V_c^2 - V_c,mf^2)/V_c^2 increases strongly as sigma_t is approached from\nabove.", "Recently H(z) data obtained from differential ages of galaxies have been\nproposed as a new geometrical probe of dark energy. In this paper we use those\ndata, combined with other background tests (CMB shift and SNIa data), to\nconstrain a set of general relativistic dark energy models together with some\nother models motivated by extra dimensions. Our analysis rests mostly on\nBayesian statistics, and we conclude that LCDM is at least substantially\nfavoured, and that braneworld models are less favoured than general\nrelativistic ones.", "The GLAST Burst Monitor (GBM) will augment the capabilities of GLAST for the\ndetection of cosmic gamma-ray bursts by extending the energy range (20 MeV to >\n300 GeV) of the Large Area Telescope (LAT) towards lower energies by 2\nBGO-detectors (150 keV to 30 MeV) and 12 NaI(Tl) detectors (10 keV to 1 MeV).\nThe physical detector response of the GBM instrument for GRBs is determined\nwith the help of Monte Carlo simulations, which are supported and verified by\non-ground calibration measurements, performed extensively with the individual\ndetectors at the MPE in 2005. All flight and spare detectors were irradiated\nwith calibrated radioactive sources in the laboratory (from 14 keV to 4.43\nMeV). The energy/channel-relations, the dependences of energy resolution and\neffective areas on the energy and the angular responses were measured. Due to\nthe low number of emission lines of radioactive sources below 100 keV,\ncalibration measurements in the energy range from 10 keV to 60 keV were\nperformed with the X-ray radiometry working group of the\nPhysikalisch-Technische Bundesanstalt (PTB) at the BESSY synchrotron radiation\nfacility, Berlin.", "The density functional approach is used to study the gas-to-liquid and\nliquid-to-gas nucleation phenomena in a fluid of two-level atoms in an external\nelectrical field. The influence of the field on the surface tension and\nnucleation and cavitation barriers is discussed.", "The extension of the first-principles generalized pseudopotential theory\n(GPT) to transition-metal (TM) aluminides produces pair and many-body\ninteractions that allow efficient calculations of total energies. In\naluminum-rich systems treated at the pair-potential level, one practical\nlimitation is a transition-metal over-binding that creates an unrealistic TM-TM\nattraction at short separations in the absence of balancing many-body\ncontributions. Even with this limitation, the GPT pair potentials have been\nused effectively in total-energy calculations for Al-TM systems with TM atoms\nat separations greater than 4 AA. An additional potential term may be added for\nsystems with shorter TM atom separations, formally folding repulsive\ncontributions of the three- and higher-body interactions into the pair\npotentials, resulting in structure-dependent TM-TM potentials. Towards this\nend, we have performed numerical ab-initio total-energy calculations using VASP\n(Vienna Ab Initio Simulation Package) for an Al-Co-Ni compound in a particular\nquasicrystalline approximant structure. The results allow us to fit a\nshort-ranged, many-body correction of the form a(r_0/r)^{b} to the GPT pair\npotentials for Co-Co, Co-Ni, and Ni-Ni interactions.", "This study investigates in detail the finite-size scaling of the\ntwo-dimensional irrationally frustrated XY model. By means of Monte Carlo\nsimulations with entropic sampling, we examine the size dependence of the\nspecific heat, and find remarkable deviation from the conventional finite-size\nscaling theory, which reveals novel intrinsic finite-size effects. Relaxation\ndynamics of the system is also considered, and correspondingly, finite-size\nscaling of the relaxation time is examined, again giving evidence for the\nintrinsic finite-size effects and suggesting a zero-temperature glass\ntransition.", "We study theoretically the ultrafast nonlinear optical response of quantum\nwell excitons in a perpendicular magnetic field. We show that for\nmagnetoexcitons confined to the lowest Landau levels, the third-order\nfour-wave-mixing (FWM) polarization is dominated by the exciton-exciton\ninteraction effects. For repulsive interactions, we identify two regimes in the\ntime-evolution of the optical polarization characterized by exponential and\n{\\em power law} decay of the FWM signal. We describe these regimes by deriving\nan analytical solution for the memory kernel of the two-exciton wave-function\nin strong magnetic field. For strong exciton-exciton interactions, the decay of\nthe FWM signal is governed by an antibound resonance with an\ninteraction-dependent decay rate. For weak interactions, the continuum of\nexciton-exciton scattering states leads to a long tail of the time-integrated\nFWM signal for negative time delays, which is described by the product of a\npower law and a logarithmic factor. By combining this analytic solution with\nnumerical calculations, we study the crossover between the exponential and\nnon-exponential regimes as a function of magnetic field. For attractive\nexciton-exciton interaction, we show that the time-evolution of the FWM signal\nis dominated by the biexcitonic effects.", "Many extra-solar planets discovered over the past decade are gas giants in\ntight orbits around their host stars. Due to the difficulties of forming these\n`hot Jupiters' in situ, they are generally assumed to have migrated to their\npresent orbits through interactions with their nascent discs. In this paper, we\npresent a systematic study of giant planet migration in power law discs. We\nfind that the planetary migration rate is proportional to the disc surface\ndensity. This is inconsistent with the assumption that the migration rate is\nsimply the viscous drift speed of the disc. However, this result can be\nobtained by balancing the angular momentum of the planet with the viscous\ntorque in the disc. We have verified that this result is not affected by\nadjusting the resolution of the grid, the smoothing length used, or the time at\nwhich the planet is released to migrate.", "Our universe is observed to be accelerating due to the dominant dark energy\nwith negative pressure. The dark energy equation of state (w) holds a key to\nunderstanding the ultimate fate of the universe. The cosmic voids behave like\nbubbles in the universe so that their shapes must be quite sensitive to the\nbackground cosmology. Assuming a flat universe and using the priors on the\nmatter density parameter (Omega_m) and the dimensionless Hubble parameter (h),\nwe demonstrate analytically that the ellipticity evolution of cosmic voids may\nbe a sensitive probe of the dark energy equation of state. We also discuss the\nparameter degeneracy between w and Omega_m.", "The nitrogen fluorescence induced in air is used to detect ultra-high energy\ncosmic rays and to measure their energy. The precise knowledge of the absolute\nfluorescence yield is the key quantity to improve the accuracy on the cosmic\nray energy. The total yield has been measured in dry air using a 90Sr source\nand a [300-430 nm] filter. The fluorescence yield in air is 4.23 $\\pm$ 0.20\nphotons per meter when normalized to 760 mmHg, 15 degrees C and with an\nelectron energy of 0.85 MeV. This result is consistent with previous\nexperiments made at various energies, but with an accuracy improved by a factor\nof about 3. For the first time, the absolute continuous spectrum of nitrogen\nexcited by 90Sr electrons has also been measured with a spectrometer. Details\nof this experiment are given in one of the author's PhD thesis [32].", "Piezoelectric quartz tuning forks have been employed as the force sensor in a\ndynamic mode scanning force microscope operating at temperatures down to 1.7 K\nat He-gas pressures of typically 5 mbar. An electrochemically etched tungsten\ntip glued to one of the tuning fork prongs acts as the local force sensor. Its\noscillation amplitude can be tuned between a few angstroms and tens of\nnanometers. Quality factors of up to 120000 allow a very accurate measurement\nof small frequency shifts. Three calibration procedures are compared which\nallow the determination of the proportionality constant between frequency shift\nand local force gradient based on the harmonic oscillator model and on\nelectrostatic forces. The calibrated sensor is then used for a study of the\ninteraction between the tip and a HOPG substrate. Force gradient and dissipated\npower can be recorded simultane-ously. It is found that during approaching the\ntip to the sample considerable power starts to be dissipated although the force\ngradient is still negative, i.e. the tip is still in the attractive regime.\nThis observation concurs with experiments with true atomic resolution which\nseem to require the same tip-sample separation.", "With the anticipated launch of GLAST, the existing X-ray telescopes, and the\nenhanced capabilities of the new generation of TeV telescopes, developing tools\nfor modeling the variability of high energy sources such as blazars is becoming\na high priority. We point out the serious, innate problems one zone\nsynchrotron-self Compton models have in simulating high energy variability. We\nthen present the first steps toward a multi zone model where non-local, time\ndelayed Synchrotron-self Compton electron energy losses are taken into account.\nBy introducing only one additional parameter, the length of the system, our\ncode can simulate variability properly at Compton dominated stages, a situation\ntypical of flaring systems. As a first application, we were able to reproduce\nvariability similar to that observed in the case of the puzzling `orphan' TeV\nflares that are not accompanied by a corresponding X-ray flare.", "High-resolution infrared spectroscopy in the 2.3-4.6 micron region is\nreported for the peculiar A supergiant, single-lined spectroscopic binary HR\n4049. Lines from the CO fundamental and first overtone, OH fundamental, and\nseveral H2O vibration-rotation transitions have been observed in the\nnear-infrared spectrum. The spectrum of HR 4049 appears principally in emission\nthrough the 3 and 4.6 micron region and in absorption in the 2 micron region.\nThe 4.6 micron spectrum shows a rich 'forest' of emission lines. All the\nspectral lines observed in the 2.3-4.6 micron spectrum are shown to be\ncircumbinary in origin. The presence of OH and H2O lines confirm the\noxygen-rich nature of the circumbinary gas which is in contrast to the\npreviously detected carbon-rich material. The emission and absorption line\nprofiles show that the circumbinary gas is located in a thin, rotating layer\nnear the dust disk. The properties of the dust and gas circumbinary disk and\nthe spectroscopic orbit yield masses for the individual stars, M_AI~0.58 Msolar\nand M_MV~0.34 Msolar. Gas in the disk also has an outward flow with a velocity\nof $\\gtrsim$ 1 km/s. The severe depletion of refractory elements but near-solar\nabundances of volatile elements observed in HR 4049 results from abundance\nwinnowing. The separation of the volatiles from the grains in the disk and the\nsubsequent accretion by the star are discussed. Contrary to prior reports, the\nHR 4049 carbon and oxygen isotopic abundances are typical AGB values:\n12C/13C=6^{+9}_{-4} and 16O/17O>200.", "The low temperature specific heat C(H) of several rare-earth manganites\n(La_(0.7)Sr_(0.3)MnO_(3), Nd_(0.5)Sr_(0.5)MnO_(3), Pr_(0.5)Sr_(0.5)MnO_(3),\nLa_(0.67)Ca_(0.33)MnO$_(3), La_(0.5)Ca_(0.5)MnO_(3), La_(0.45)Ca_(0.55)MnO_(3)\nand La_(0.33)Ca_(0.67)MnO_(3)) was measured as a function of magnetic field. We\nobserved behaviour consistent with thermodynamic expectations, i.e., C(H)\ndecreases with field for ferromagnetic metallic compounds by an amount which is\nin quantitative agreement with spin wave theory. We also find that C(H)\nincreases with field in most compounds with a charge-ordered antiferromagnetic\nground state. In compounds which show evidence of a coexistence of\nferromagnetic metallic and antiferromagnetic charge-ordered states, C(H)\ndisplays some unusual non-equilibrium effects presumably associated with the\nphase-separation of the two states. We also observe a large anomalous low\ntemperature specific heat at the doping induced metal-insulator transition (at\nx = 0.50) in La_(1-x)Ca_(x)MnO_(3).", "Context:A significant fraction of progenitors for long gamma-ray bursts\n(GRBs) are believed to be massive stars. The investigation of long GRBs\ntherefore requires modeling the propagation of ultra-relativistic blastwaves\nthrough the circumburst medium surrounding massive stars. We simulate the\nexpansion of an isotropic, adiabatic relativistic fireball into the wind-shaped\nmedium around a massive GRB progenitor. The circumburst medium is composed of a\nrealistically stratified stellar wind zone up to its termination shock,\nfollowed by a region of shocked wind characterized by a constant density. Aims:\nWe followed the evolution of the blastwave through all its stages, including\nthe extremely rapid acceleration up to a Lorentz factor 75 flow, its\ndeceleration by interaction with stellar wind, its passage of the wind\ntermination shock, until its propagation through shocked wind. Methods: We used\nthe adaptive mesh refinement versatile advection code to follow the evolution\nof the fireball. Results: We show that the acceleration from purely thermal to\nultra-relativistic kinetic regimes is abrupt and produces an internally\nstructured blastwave. We resolved the structure of this ultra-relativistic\nshell in all stages, thanks to the adaptive mesh. We comment on the dynamical\nroles played by forward and reverse shock pairs in the phase of interaction\nwith the free stellar wind and clearly identify the complex shock-dominated\nstructure created when the shell crosses the terminal shock. Conclusion: We\nshow that in our model where the terminal shock is taken relatively close to\nthe massive star, the phase of self-similar deceleration of Blandford-McKee\ntype can only be produced in the constant density, shocked wind zone.", "We present high-resolution, multiwavelength continuum and molecular-line\nimages of the massive star forming region IRAS 18317-0757. The IR through mm\nspectral energy distribution can be approximated by a two-temperature model (25\nand 63 K) with a total luminosity of approximately log(L/Lsun)=5.2. Previous\nsubmm imaging resolved this region into a cluster of 5 dust cores, one of which\nis associated with the UCHII region G23.96+0.15, and another with an H2O maser.\nIn our new 2.7 mm continuum image, only the UCHII region is detected, with\ntotal flux and morphology in good agreement with the free-free emission in VLA\ncm-wave maps. For the other four objects, the nondetections at 2.7 mm and in\nthe MSX mid-IR bands are consistent with cool dust emission with a temperature\nof 13-40K and luminosity of 1000-40000 Lsun. By combining single-dish and\ninterferometric data, we have identified over two dozen virialized C18O cores\nin this region that contain ~40% of the total molecular gas mass present. While\nthe overall extent of the C18O and dust emission is similar, the emission peaks\ndo not correlate well in detail. At least 11 of the 123 stars identified by\n2MASS in this region are likely to be within the star-forming cluster. Two\nstars (both associated with the UCHII region) were previously identified as O\nstars via IR spectroscopy. Most of the rest of the reddened stars have no\nobvious correlation with the C18O cores or the dust cores. In summary, our\nobservations indicate that considerable fragmentation of the molecular cloud\nhas taken place during the time required for the UCHII region to form and the O\nstars to become detectable at IR wavelengths. Additional star formation appears\nto be ongoing on the periphery of the central region, where up to four B-type\n(proto)stars have formed among a substantial number of C18O molecular cores.", "Did time begin at a Big Bang? Will the present expansion of the universe last\nfor a finite or infinite time? These questions sound philosophical but are\nbecoming, now in the twenty-first century, central to the scientific study of\ncosmology. The answers, which should become clarified in the next decade or\ntwo, could have profound implications for how we see our own role in the\nuniverse. Since the original publication of Stephen Hawking's {\\it A Brief\nHistory of Time} in 1988, the answers to these questions have progressed as a\nresult of research by the community of active theoretical physicists including\nmyself. To present the underlying ideas requires discussion of a wide range of\ntopics in cosmology, especially the make up of the energy content of the\nuniverse. A brief summary of my conclusions, that of three different\npossibilities concerning the history and future of time, the least likely is\nthe conventional wisdom (time began and will never end) and most likely is a\ncyclic model (time never begins or ends), is in the short final Chapter which\ncould be read first. To understand the reasoning leading to my conclusions\ncould encourage reading of my entire book. My hope in writing this, my first\npopular book, is that it will engender reflection about time. Many a\nnon-scientist may already hold a philosophical opinion about whether time\nbegins and ends. This book's aim is to present some recently discovered\nscientific facts which can focus the reader's consideration of the two short\nquestions in my title.", "Fixed income markets share many features with the equity markets. However\nthere are significant differences as well and many attempts have been done in\nthe past to develop specific tools which describe (and possibly forecasts) the\nbehavior of such markets.\n  For instance, a correct pricing of fixed income securities with fixed cache\nflows requires the knowledge of the {\\it term structure} of interest rates. A\nnumber of techniques have been proposed for estimating and interpreting the\nterm structure, yet solid theoretical foundations and a comparative assessment\nof the results produced by these techniques are not available.\n  In this paper we define the fundamental concepts with a mathematical\nterminology. Besides that, we report about an extensive set of experiments\nwhose scope is to point out the strong and weak points of the most widely used\napproaches in this field.", "The magneto-rotational instability is presently the most promising source of\nturbulent transport in accretion disks. However, some important issues still\nneed to be addressed to quantify the role of MRI in disks; in particular no\nsystematic investigation of the role of the physical dimensionless parameters\nof the problem on the dimensionless transport has been undertaken yet. First,\nwe complete existing investigations on the field strength dependence by showing\nthat the transport in high magnetic pressure disks close to marginal stability\nis highly time-dependent and surprisingly efficient. Second, we bring to light\na significant dependence of the global transport on the magnetic Prandtl\nnumber, with $\\alpha\\propto Pm^\\delta$ for the explored range: $0.12<Pm<8$ and\n$200<Re<6400$ ($\\delta$ being in the range 0.25 to 0.5). We show that the\ndimensionless transport is not correlated to the dimensionless linear growth\nrate, contrarily to a largely held expectation. More generally, these results\nstress the need to control dissipation processes in astrophysical simulations.", "We consider a market where many agents trade many different types of products\nwith each other. We model development of collective modes in this market, and\nquantify these by fluctuations that scale with time with a Hurst exponent of\nabout 0.7. We demonstrate that individual products in the model occationally\nbecome globally accepted means of exchange, and simultaneously become very\nactively traded. Thus collective features similar to money spontaneously\nemerge, without any a priori reason.", "We study the spectral and energetics properties of 47 long-duration gamma-ray\nbursts (GRBs) with known redshift, all of them detected by the Swift satellite.\nDue to the narrow energy range (15-150 keV) of the Swift-BAT detector, the\nspectral fitting is reliable only for fitting models with 2 or 3 parameters. As\nhigh uncertainty and correlation among the errors is expected, a careful\nanalysis of the errors is necessary. We fit both the power law (PL, 2\nparameters) and cut--off power law (CPL, 3 parameters) models to the\ntime-integrated spectra of the 47 bursts, and present the corresponding\nparameters, their uncertainties, and the correlations among the uncertainties.\nThe CPL model is reliable only for 29 bursts for which we estimate the nuf_nu\npeak energy Epk. For these GRBs, we calculate the energy fluence and the rest-\nframe isotropic-equivalent radiated energy, Eiso, as well as the propagated\nuncertainties and correlations among them. We explore the distribution of our\nhomogeneous sample of GRBs on the rest-frame diagram E'pk vs Eiso. We confirm a\nsignificant correlation between these two quantities (the \"Amati\" relation) and\nwe verify that, within the uncertainty limits, no outliers are present. We also\nfit the spectra to a Band model with the high energy power law index frozen to\n-2.3, obtaining a rather good agreement with the \"Amati\" relation of non-Swift\nGRBs.", "We examine the orbits of satellite galaxies identified in a suite of\nN-body/gasdynamical simulations of the formation of $L_*$ galaxies in a LCDM\nuniverse. Most satellites follow conventional orbits; after turning around,\nthey accrete into their host halo and settle on orbits whose apocentric radii\nare steadily eroded by dynamical friction. However, a number of outliers are\nalso present, we find that ~1/3 of satellites identified at $z=0$ are on\nunorthodox orbits, with apocenters that exceed their turnaround radii. This\npopulation of satellites on extreme orbits consists typically of the faint\nmember of a satellite pair that has been ejected onto a highly-energetic orbit\nduring its first approach to the primary. Since the concurrent accretion of\nmultiple satellite systems is a defining feature of hierarchical models of\ngalaxy formation, we speculate that this three-body ejection mechanism may be\nthe origin of (i) some of the newly discovered high-speed satellites around M31\n(such as Andromeda XIV); (ii) some of the distant fast-receding Local Group\nmembers, such as Leo I; and (iii) the oddly isolated dwarf spheroidals Cetus\nand Tucana in the outskirts of the Local Group. Our results suggest that care\nmust be exercised when using the orbits of the most weakly bound satellites to\nplace constraints on the total mass of the Local Group.", "The dynamics of electrons and atoms interacting with intense and ultrashort\noptical pulses presents an important problem in physics that cuts across\ndifferent materials such as semiconductors and metals. The currently available\nlaser pulses, as short as 5 fs, provide a time resolution shorter than the\ndephasing and relaxation times in many materials. This allows for a systematic\nstudy of many-body effects using nonlinear optical spectroscopy. In this review\narticle, we discuss the role of Coulomb correlations in the ultrafast dynamics\nof modulation-doped quantum wells and metal nanoparticles. We focus in\nparticular on the manifestations of non-Markovian memory effects induced by\nstrong electron-hole and electron-plasmon correlations.", "It is presumed that the observed cosmic rays up to about $3\\times 10^{18}$ eV\nare of Galactic origin, the particles being the ones which are found in the\ncomposition of the stellar winds of stars that explode as supernova into the\ninterstellar medium (ISM) or into their winds. These particles are accelerated\nin the supernova shock. In order to obtain the observed cosmic ray spectrum it\nis necessary to take into account the diffusive losses in the Galaxy (which are\nmaking the energy spectrum more steeper). Another modification of the source\nspectrum is due to the fragmentation (spallation) of the cosmic ray particles,\nafter their collision with the ISM atoms. In this paper we are proving that\nsome particles are injected in the supernova shock one or two time ionized,\nand, also, that the contribution of massive stars ($30 M_{\\odot}\\leq M\\leq 50\nM_{\\odot}$) accelerated particles to cosmic rays (where the winds are highly\nenriched in heavy elements) is 1:2 for elements with $Z\\geq 6$. Another goal of\nthis paper is to check if the particles are injected with the same velocity,\nenergy or momentum.", "We calculate eclipsing light curves for accretion flows around a rotating\nblack hole taking into account the atmospheric effects of the companion star.\nIn the cases of no atmospheric effects, the light curves contain the\ninformation of the black hole spin because most of the X-ray photons around 1\nkeV usually come from the blueshifted part of the accretion flow near the black\nhole shadow, and the size and the position of the black hole shadow depend on\nthe spin. In these cases, when most of the emission comes from the vicinity of\nthe event horizon, the light curves become asymmetric at ingress and egress. We\nnext investigate the atmospheric absorption and scattering effects of the\ncompanion stars. By using the solar-type atmospheric model, we have taken into\naccount the atmospheric effects of the companion star, such as the\nphotoionization by HI and HeI. We found that the eclipsing light curves\nobserved at 1 keV possibly contain the information of the black hole spin.\nHowever, in our atmospheric model, the effects of the atmosphere are much\nlarger than the effects of the black hole spin. Therefore, even in the case\nthat the light curves contain the information of the black hole spin, it may be\ndifficult to extract the information of the black hole spin if we do not have\nthe realistic atmospheric profiles, such as the temperature, and the number\ndensities for several elements. Even in such cases, the light-curve asymmetries\ndue to the rotation of the accretion disc exist. Only when we have the reliable\natmospheric model, in principle, the information of the strong-gravity regions,\nsuch as the black hole spin, can be obtained from the eclipsing light curves.", "A new semiclassical approach to linear (L) and nonlinear (NL) one-dimensional\nSchr\\\"odinger equation (SE) is presented. Unlike the usual WKB solution, our\nsolution does not diverge at the classical turning point. For LSE, our\nzeroth-order solution, when expanded in powers of \\hbar, agrees with the usual\nWKB solution. For NLSE, our zeroth-order solution includes quantum corrections\nto the Thomas-Fermi solution, thereby giving a smoothly decaying wave function\ninto the forbidden region.", "I review the status of science with wide field surveys. For many decades\nsurveys have been the backbone of astronomy, and the main engine of discovery,\nas we have mapped the sky at every possible wavelength. Surveys are an\nefficient use of resources. They are important as a fundamental resource; to\nmap intrinsically large structures; to gain the necessary statistics to address\nsome problems; and to find very rare objects. I summarise major recent wide\nfield surveys - 2MASS, SDSS, 2dfGRS, and UKIDSS - and look at examples of the\nexciting science they have produced, covering the structure of the Milky Way,\nthe measurement of cosmological parameters, the creation of a new field\nstudying substellar objects, and the ionisation history of the Universe. I then\nlook briefly at upcoming projects in the optical-IR survey arena - VISTA,\nPanSTARRS, WISE, and LSST. Finally I ask, now we have opened up essentially all\nwavelength windows, whether the exploration of survey discovery space is ended.\nI examine other possible axes of discovery space, and find them mostly to be\ntoo expensive to explore or otherwise unfruitful, with two exceptions : the\nfirst is the time axis, which we have only just begun to explore properly; and\nthe second is the possibility of neutrino astrophysics.", "Observations of stellar activity cycles provide an opportunity to study\nmagnetic dynamos under many different physical conditions. Space-based\nasteroseismology missions will soon yield useful constraints on the interior\nconditions that nurture such magnetic cycles, and will be sensitive enough to\ndetect shifts in the oscillation frequencies due to the magnetic variations. We\nderive a method for predicting these shifts from changes in the Mg II activity\nindex by scaling from solar data. We demonstrate this technique on the\nsolar-type subgiant beta Hyi, using archival International Ultraviolet Explorer\nspectra and two epochs of ground-based asteroseismic observations. We find\nqualitative evidence of the expected frequency shifts and predict the optimal\ntiming for future asteroseismic observations of this star.", "We present a morphological study of galaxies in the A901/902 supercluster\nfrom the COMBO-17 survey. A total of 570 galaxies with photometric redshifts in\nthe range 0.155 < z_phot < 0.185 are visually classified by three independent\nclassifiers to M_V=-18. These morphological classifications are compared to\nlocal galaxy density, distance from the nearest cluster centre, local surface\nmass density from weak lensing, and photometric classification. At high local\ngalaxy densities, log(Sigma_10 /Mpc^2) > 1.5, a classical morphology-density\nrelation is found. A correlation is also found between morphology and local\nprojected surface mass density, but no trend is observed with distance to the\nnearest cluster. This supports the finding that local environment is more\nimportant to galaxy morphology than global cluster properties. The breakdown of\nthe morphological catalogue by colour shows a dominance of blue galaxies in the\ngalaxies displaying late-type morphologies and a corresponding dominance of red\ngalaxies in the early-type population. Using the 17-band photometry from\nCOMBO-17, we further split the supercluster red sequence into old passive\ngalaxies and galaxies with young stars and dust according to the prescription\nof Wolf et al. (2005). We find that the dusty star-forming population describes\nan intermediate morphological group between late-type and early-type galaxies,\nsupporting the hypothesis that field and group spiral galaxies are transformed\ninto S0s and, perhaps, ellipticals during cluster infall.", "We study the structural properties of self-attracting walks in d dimensions\nusing scaling arguments and Monte Carlo simulations. We find evidence for a\ntransition analogous to the \\Theta transition of polymers. Above a critical\nattractive interaction u_c, the walk collapses and the exponents \\nu and k,\ncharacterising the scaling with time t of the mean square end-to-end distance\n<R^2> ~ t^{2 \\nu} and the average number of visited sites <S> ~ t^k, are\nuniversal and given by \\nu=1/(d+1) and k=d/(d+1). Below u_c, the walk swells\nand the exponents are as with no interaction, i.e. \\nu=1/2 for all d, k=1/2 for\nd=1 and k=1 for d >= 2. At u_c, the exponents are found to be in a different\nuniversality class.", "We consider the phase diagram of a classical fluid in the presence of a\nrandom pinning potential of arbitrary strength. Introducing replicas for\naveraging over the quenched disorder, we use the hypernetted chain\napproximation to calculate the correlations in the replicated liquid. The\nfreezing transition of the liquid into a nearly crystalline state is studied\nusing a density functional approach, and the liquid-to-glass transition is\nstudied using a phenomenological replica symmetry breaking approach introduced\nby Mezard and Parisi. The first-order liquid-to-crystal transition is found to\nchange to a continuous liquid-to-glass transition as the strength of the\ndisorder is increased above a threshold value.", "Non-equilibrium dynamics of classical random Ising spin chains are studied\nusing asymptotically exact real space renormalization group. Specifically the\nrandom field Ising model with and without an applied field (and the Ising spin\nglass (SG) in a field), in the universal regime of a large Imry Ma length so\nthat coarsening of domains after a quench occurs over large scales. Two types\nof domain walls diffuse in opposite Sinai random potentials and mutually\nannihilate. The domain walls converge rapidly to a set of system-specific\ntime-dependent positions {\\it independent of the initial conditions}. We obtain\nthe time dependent energy, magnetization and domain size distribution\n(statistically independent). The equilibrium limits agree with known exact\nresults. We obtain exact scaling forms for two-point equal time correlation and\ntwo-time autocorrelations. We also compute the persistence properties of a\nsingle spin, of local magnetization, and of domains. The analogous quantities\nfor the spin glass are obtained. We compute the two-point two-time correlation\nwhich can be measured by experiments on spin-glass like systems. Thermal\nfluctuations are found to be dominated by rare events; all moments of truncated\ncorrelations are computed. The response to a small field applied after waiting\ntime $t_w$, as measured in aging experiments, and the fluctuation-dissipation\nratio $X(t,t_w)$ are computed. For $(t-t_w) \\sim t_w^{\\hat{\\alpha}}$,\n$\\hat{\\alpha} <1$, it equals its equilibrium value X=1, though time\ntranslational invariance fails. It exhibits for $t-t_w \\sim t_w$ aging regime\nwith non-trivial $X=X(t/t_w) \\neq 1$, different from mean field.", "We discuss the current status of a computational approach which allows to\nevaluate the dielectric matrix, and hence electronic excitations like optical\nproperties, including local field and excitonic effects. We introduce a recent\nnumerical development which greatly reduces the use of memory in such type of\ncalculations, and hence eliminates one of the bottlenecks for the application\nto complex systems. We present recent applications of the method, focusing our\ninterest on insulating oxides.", "It is widely accepted that the free energy F(H) of the two-dimensional Ising\nmodel in the ferromagnetic phase T<T_c has an essential branch cut singularity\nat the origin H=0. The phenomenological droplet theory predicts that near the\ncut drawn along the negative real axis H<0, the imaginary part of the free\nenergy per lattice site has the form Im F[exp (\\pm i\\pi |H|)] = \\pm B |H| exp\n(-A/|H|) for small |H|. We verify this prediction in analytical perturbative\ntransfer matrix calculations for the square lattice Ising model for all\ntemperatures 0<T<T_c and arbitrary anisotropy ratio J_1/J_2. We obtain an\nexpression for the constant A which coincides exactly with the prediction of\nthe droplet theory. For the amplitude B we obtain B =\\pi M/18, where M is the\nequilibrium spontaneous magnetization. In addition we find discrete-lattice\ncorrections to the above mentioned phenomenological formula for ImF, which\noscillate in H^{-1}.", "The linearized relativistic magnetohydrodynamic (RMHD) equations describing a\nuniform axially magnetized cylindrical relativistic jet spine embedded in a\nuniform axially magnetized relativistically moving sheath are derived. The\ndisplacement current is retained in the equations so that effects associated\nwith Alfven wave propagation near light speed can be studied. A dispersion\nrelation for the normal modes is obtained. Analytical solutions for the normal\nmodes in the low and high frequency limits are found and a general stability\ncondition is determined. A trans-Alfvenic and even a super-Alfvenic\nrelativistic jet spine can be stable to velocity shear driven Kelvin-Helmholtz\nmodes. The resonance condition for maximum growth of the normal modes is\nobtained in the kinetically and magnetically dominated regimes. Numerical\nsolution of the dispersion relation verifies the analytical solutions and is\nused to study the regime of high sound and Alfven speeds.", "Gamma-Ray Bursts (GRBs) have been detected at GeV energies by EGRET and\nmodels predict emission at > 100 GeV. Milagro is a wide field (2 sr) high duty\ncycle (> 90 %) ground based water Cherenkov detector that records extensive air\nshowers in the energy range 100 GeV to 100 TeV. We have searched for very high\nenergy emission from a sample of 106 gamma-ray bursts (GRB) detected since the\nbeginning of 2000 by BATSE, BeppoSax, HETE-2, INTEGRAL, Swift or the IPN. No\nevidence for emission from any of the bursts has been found and we present\nupper limits from these bursts.", "By calculation and analysis of the bare conduction bands in a large number of\nhole-doped high-temperature superconductors, we have identified the energy of\nthe so-called axial-orbital as the essential, material-dependent parameter. It\nis uniquely related to the range of the intra-layer hopping. It controls the Cu\n4s-character, influences the perpendicular hopping, and correlates with the\nobserved Tc at optimal doping. We explain its dependence on chemical\ncomposition and structure, and present a generic tight-binding model.", "Aims: We analyze the available information on the star BD+43 3654 to\ninvestigate the possibility that it may have had its origin in the massive OB\nassociation Cygnus OB2.\n  Methods: We present new spectroscopic observations allowing a reliable\nspectral classification of the star, and discuss existing MSX observations of\nits associated bow shock and astrometric information not previously studied.\n  Results: Our observations reveal that BD+43 3654 is a very early and luminous\nstar of spectral type O4If, with an estimated mass of (70 +/- 15) solar masses\nand an age of about 1.6 Myr. The high spatial resolution of the MSX\nobservations allows us to determine its direction of motion in the plane of the\nsky by means of the symmetry axis of the well-defined bow shock, which matches\nwell the orientation expected from the proper motion. Tracing back its path\nacross the sky we find that BD+43 3654 was located near the central, densest\nregion of Cygnus OB2 at a time in the past similar to its estimated age.\n  Conclusions: BD+43 3654 turns out to be one of the three most massive runaway\nstars known, and it most likely formed in the central region of Cygnus OB2. A\nrunaway formation mechanism by means of dynamical ejection is consistent with\nour results.", "We present the main results of the PhD Thesis carried out by\nL\\'opez-S\\'anchez (2006), in which a detailed morphological, photometrical and\nspectroscopical analysis of a sample of 20 Wolf-Rayet (WR) galaxies was\nrealized. The main aims are the study of the star formation and O and WR\nstellar populations in these galaxies and the role that interactions between\nlow surface companion objects have in the triggering of the bursts. We analyze\nthe morphology, stellar populations, physical conditions, chemical abundances\nand kinematics of the ionized gas, as well as the star-formation activity of\neach system.", "Using TDPAD experiment and local spin density calculations, we have observed\nlarge 4d moments on isolated Mo atoms at substitutional and octahedral\ninterstitial lattice sites in Yb metal, showing Curie-Weiss local\nsusceptibility and Korringa like spin relaxation rate. As a surprising feature,\ndespite strong hybridization with the Yb neighbours, interstitial Mo atoms show\nhigh moment stability with small Kondo temperature. While, magnetism of Mo, at\nsubstitutional site is consistent with Kondo type antiferromagnetic d-sp\nexchange interaction, we suggest that moment stability at the interstitial site\nis strongly influenced by ferromagnetic polarization of Yb-4f5d band electrons.", "Numerical simulations of Milky-Way size Cold Dark Matter (CDM) halos predict\na steeply rising mass function of small dark matter subhalos and a substructure\ncount that greatly outnumbers the observed satellites of the Milky Way. Several\nproposed explanations exist, but detailed comparison between theory and\nobservation in terms of the maximum circular velocity (Vmax) of the subhalos is\nhampered by the fact that Vmax for satellite halos is poorly constrained. We\npresent comprehensive mass models for the well-known Milky Way dwarf\nsatellites, and derive likelihood functions to show that their masses within\n0.6 kpc (M_0.6) are strongly constrained by the present data. We show that the\nM_0.6 mass function of luminous satellite halos is flat between ~ 10^7 and 10^8\nM_\\odot. We use the ``Via Lactea'' N-body simulation to show that the M_0.6\nmass function of CDM subhalos is steeply rising over this range. We rule out\nthe hypothesis that the 11 well-known satellites of the Milky Way are hosted by\nthe 11 most massive subhalos. We show that models where the brightest\nsatellites correspond to the earliest forming subhalos or the most massive\naccreted objects both reproduce the observed mass function. A similar analysis\nwith the newly-discovered dwarf satellites will further test these scenarios\nand provide powerful constraints on the CDM small-scale power spectrum and warm\ndark matter models.", "AIMS: We investigate whether the morphology of bilateral supernova remnants\n(BSNRs) observed in the radio band is determined mainly either by a non-uniform\ninterstellar medium (ISM) or by a non-uniform ambient magnetic field.\n  METHODS: We perform 3-D MHD simulations of a spherical SNR shock propagating\nthrough a magnetized ISM. Two cases of shock propagation are considered: 1)\nthrough a gradient of ambient density with a uniform ambient magnetic field; 2)\nthrough a homogeneous medium with a gradient of ambient magnetic field\nstrength. From the simulations, we synthesize the synchrotron radio emission,\nmaking different assumptions about the details of acceleration and injection of\nrelativistic electrons.\n  RESULTS: We find that asymmetric BSNRs are produced if the line-of-sight is\nnot aligned with the gradient of ambient plasma density or with the gradient of\nambient magnetic field strength. We derive useful parameters to quantify the\ndegree of asymmetry of the remnants that may provide a powerful diagnostic of\nthe microphysics of strong shock waves through the comparison between models\nand observations.\n  CONCLUSIONS: BSNRs with two radio limbs of different brightness can be\nexplained if a gradient of ambient density or, most likely, of ambient magnetic\nfield strength is perpendicular to the radio limbs. BSNRs with converging\nsimilar radio arcs can be explained if the gradient runs between the two arcs.", "The problem of creating well-collimated beams of atoms escaping from a trap\nis studied. This problem is of high importance for the realization of atom\nlasers. Nonadiabatic dynamics of neutral atoms in nonuniform magnetic fields,\ntypical of quadrupole magnetic traps, has been considered. The main result of\nthis report is that an unusual semiconfining regime of motion is found, when\natoms are confined from one side of an axis but are not confined from another\nside. This regime can be achieved by means of only magnetic fields. The formed\natomic beam can be forwarded in arbitrary direction.", "Using a standing light wave trap, a stable quasi-one-dimensional attractive\ndilute-gas Bose-Einstein condensate can be realized. In a mean-field\napproximation, this phenomenon is modeled by the cubic nonlinear Schr\\\"odinger\nequation with attractive nonlinearity and an elliptic function potential of\nwhich a standing light wave is a special case. New families of stationary\nsolutions are presented. Some of these solutions have neither an analog in the\nlinear Schr\\\"odinger equation nor in the integrable nonlinear Schr\\\"odinger\nequation. Their stability is examined using analytic and numerical methods.\nTrivial-phase solutions are experimentally stable provided they have nodes and\ntheir density is localized in the troughs of the potential. Stable\ntime-periodic solutions are also examined.", "The standard cosmological model is based on general relativity and includes\ndark matter and dark energy. An important prediction of this model is a fixed\nrelationship between the gravitational potentials responsible for gravitational\nlensing and the matter overdensity. Alternative theories of gravity often make\ndifferent predictions for this relationship. We propose a set of measurements\nwhich can test the lensing/matter relationship, thereby distinguishing between\ndark energy/matter models and models in which gravity differs from general\nrelativity. Planned optical, infrared and radio galaxy and lensing surveys will\nbe able to measure $E_G$, an observational quantity whose expectation value is\nequal to the ratio of the Laplacian of the Newtonian potentials to the peculiar\nvelocity divergence, to percent accuracy. We show that this will easily\nseparate alternatives such as $\\Lambda$CDM, DGP, TeVeS and $f(R)$ gravity.", "We report on Monte Carlo studies of the kinetic exchange model for (III,Mn)V\nferromagnetic semiconductors in which S=5/2 local moments, representing Mn^{2+}\nions, are exchange coupled to band electrons. We treat the Mn^{2+}$ spin\norientations as classical degrees of freedom and use the Hybrid Monte Carlo\nalgorithm to explore thermodynamically important Mn spin configurations. The\ncritical temperature T_c of the model is unambiguously signalled in our\nfinite-size simulations by pronounced peaks in fluctuations of both Mn and band\ncarrier total spins. The T_c's we obtain are, over much of the model's\nparameter space, substantially smaller than those estimated using mean-field\ntheory. When mean-field theory fails, short-range magnetic order and finite\n{\\em local} carrier spin polarisation are present for temperatures\nsubstantially larger than T_{c}. For the simplest version of the model, which\nhas a single parabolic band with effective mass m^*, the dependence of T_{c} on\nm^* is sublinear at large masses, in disagreement with the mean-field theory\nresult T_{c} \\propto m^*. For the carrier densities studied, results obtained\nwith a six-band Luttinger model band Hamiltonian are in good agreement with\nthose obtained for a model with a single parabolic band whose effective mass is\nequal to the Kohn-Luttinger model heavy-hole mass.", "We present a systematic classification of the elementary excitations of\nBose-Einstein condensates in cylindrical traps in terms of their shapes. The\nclassification generalizes the concept of families of excitations first\nidentified by Hutchinson and Zaremba (1998) Phys. Rev. A 57 1280 by introducing\na second classification number that allows all possible modes to be assigned to\na family. We relate the energy ordering of the modes to their family\nclassification, and provide a simple model which explains the relationship.", "We study how the binding energy, the vibrational frequencies and the\nadsorption isotherm of CO on Pd(100) are modified when the solid is subject to\nuniform strain. The parameters controlling the thermodynamics of adsorption\n(the adsorption energy, the vibrational frequencies of the adsorbed molecules\nand the interaction energy between the molecules) have been calculated by using\ndensity functional theory. These parameters are then used in a grand canonical\nMonte Carlo simulation that determines the CO coverage when the surface is in\nthermodynamic equilibrium with a CO gas, at a specified pressure and\ntemperature. We find that this is substantially affected by the strain. Our\nresults, along with those obtained by others, suggest that the development of\n\"elastochemistry\", a study of the change in the chemical properties of a\nsurface when subjected to strain, will lead to interesting and measurable\nresults. It also suggests that differences in chemical activity between\nclusters on a support and clusters in gas phase may be partly due to the strain\ninduced when a cluster is placed on the support.", "We present millimeter and radio observations of 13 SDSS quasars at reshifts\nz~6. We observed eleven of them with the Max-Planck Millimeter Bolometer Array\n(MAMBO-2) at the IRAM 30m-telescope at 250 GHz and all of them with the Very\nLarge Array (VLA) at 1.4 GHz. Four sources are detected by MAMBO-2 and six are\ndetected by the VLA at >=3 sigma level. These sources, together with another 6\npublished in previous papers,yield a submillimeter/millimeter and radio\nobserved SDSS quasar sample at z~6. We use this sample to investigate the\nfar-infrared (FIR) andradio properties of optically bright quasars in the early\nuniverse. We compare this sample to lower redshift samples of quasars observed\ninthe submillimeter and millimeter wavelengths ((sub)mm), and find that the\ndistribution of the FIR to B band optical luminosity ratio (L_FIR/L_B) is\nsimilar from z~2 to 6. We find a weak correlation between the FIR luminosity\n(L_FIR) and B band optical luminosity (L_B) byincluding the (sub)mm observed\nsamples at all redshifts. Some strong (sub)mm detections in the z~6 sample have\nradio-to-FIR ratios within the range defined by star forming galaxies, which\nsuggests possible co-eval star forming activity with the powerful AGN in these\nsources. We calculate the rest frame radio to optical ratios (R*_1.4=L_{v,\n1.4GHz}/L_{v, 4400A}) for all of the VLA observed sources in the z~6 quasar\nsample. Only one radio detection in this sample, J083643.85+005453.3, has\nR*_1.4~40 and can be considered radio loud. There are no strong radio sources\n(R*_1.4>=100) among these SDSS quasars at z~6. These data are consistent with,\nalthough do not set strong constraints on, a decreasing radio-loud quasar\nfraction with increasing redshift.", "In previous work we showed that bright atomic solitons can arise in spinor\nBose-Einstein condensates in the form of gap solitons even for repulsive\nmany-body interactions. Here we further explore the properties of atomic gap\nsolitons and show that their internal structure can be used to both excite them\nand control their center-of-mass motion using applied laser and magnetic\nfields. As an illustration we demonstrate a nonlinear atom-optical Mach-Zehnder\ninterferometer based on gap solitons.", "We propose a simple market model where agents trade different types of\nproducts with each other by using money, relying only on local information.\nValue fluctuations of single products, combined with the condition of maximum\nprofit in transactions, readily lead to persistent fluctuations in the wealth\nof individual agents.", "We present a study of the influence of different types of disorder on systems\nin the Ising universality class by employing both a dynamical field theory\napproach and extensive Monte Carlo simulations. We reproduce some well known\nresults for the case of quenched disorder (random temperature and random\nfield), and analyze the effect of four different types of time-dependent\ndisorder scarcely studied so far in the literature. Some of them are of obvious\nexperimental and theoretical relevance (as for example, globally fluctuating\ntemperatures or random fields). All the predictions coming from our field\ntheoretical analysis are fully confirmed by extensive simulations in two and\nthree dimensions, and novel qualitatively different, non-Ising transitions are\nreported. Possible experimental setups designed to explore the described\nphenomenologies are also briefly discussed.", "We study the generation of vortices in rotating axially elongated\nmagneto-optical traps, a situation which has been realized in a recent\nexperiment (K. W. Madison, F. Chevy, W. Wohlleben, J. Dalibard, Phys. Rev.\nLett. 84, 806 (2000)). We predict that at a critical frequency the condensate\nexperiences a symmetry breaking and changes from a convex cloud to a state with\none bended vortex. We also discuss several effects which enlarge the critical\nfrequency with respect to other geometries of the trap: these are, (i) the\nfailure of the Thomas-Fermi approximation on the transverse degrees of freedom\nof the condensate, (ii) the enhancement of the transverse asymmetry of the trap\nby means of rotation and (iii) the yet unobserved bending of the vortex lines.", "We use the coherent state approximation for the skyrmion in the isotropic\nquantum Heisenberg ferromagnet to obtain analytical expression for skyrmion\nhopping integral as a function of distance. It appears the skyrmion hopping is\nrestricted by distances larger than its effective diameter. Some puzzling\nproperties of the orbital skyrmionic modes are discussed. Spin distribution in\nthese states is obtained and effect of quantum spin contraction is\ndemonstrated.The principal possibility of lowering the skyrmion energy due to a\nbonding-like state formation is illustrated.", "We study the dynamics of an incommensurate chain sliding on a periodic\nlattice, modeled by the Frenkel Kontorova hamiltonian with initial kinetic\nenergy, without damping and driving terms. We show that the onset of friction\nat all velocities is due to a novel kind of dissipative parametric resonances,\ninvolving several resonant phonons which are driven by the (dissipationless)\ncoupling of the center of mass motion to the phonons with wavevector related to\nthe modulating potential. We establish quantitative estimates for their\nexistence in finite systems and point out the analogy with the induction\nphenomenon in Fermi-Ulam-Pasta lattices.", "The connection between AGB evolution of stellar populations and infrared vs.\nultraviolet properties of the parent galaxies is reviewed relying on the\nupdated lookout provided by population-synthesis theory. In particular,\nplanetary-nebula events and hot horizontal-branch evolution are assessed in a\nunitary view to outline a plain general picture of galaxy spectrophotometric\nevolution. This will include a brief discussion of relevant phenomena such as\nthe \"UV upturn\" in ellipticals and the stellar mass loss properties along the\ngalaxy morphological sequence.", "We present CaII K and TiII optical spectra of early-type stars taken mainly\nfrom the UVES Paranal Observatory Project, plus HI 21-cm spectra from the\nVila-Elisa and Leiden-Dwingeloo surveys, which are employed to obtain distances\nto intermediate and high velocity clouds. HI emission at a velocity of -117\nkm/s towards the sightline HD 30677 with NHI=1.7x10^19 cm-2 has no\ncorresponding CaII K absorption, which has a signal-to-noise (S/N) ratio of\n610. The star has a spectroscopically determined distance of 2.7-kpc, and hence\nsets this as a firm lower distance limit towards Anti-Centre cloud ACII.\nTowards another sightline (HD 46185), HI at +122 km/s and NHI=1.2x10^19 cm-2 is\nseen. The CaII K spectrum has a S/N = 780, although no absorption is observed\nat the cloud velocity. This similarly places a firm lower distance limit of\n2.9-kpc towards this parcel of gas that may be an intermediate velocity cloud.\nThe lack of intermediate velocity (IV) CaII K absorption towards HD 196426 at a\nS/N = 500 reinforces a lower distance limit of 700-pc towards this part of\nComplex gp, where NHI is 1.1x10^19 cm-2 and velocity is +78 km/s. Additionally,\nno IV CaII K is seen in absorption in the spectrum of HD 19445, which is strong\nin HI with NHI=8x10^19 cm-2 at -42 km/s, placing a firm although uninteresting\nlower distance limit of 39-pc to this part of IV South. Finally, no HV CaII K\nabsorption is seen towards HD 115363 at a S/N = 410, placing a lower distance\nof 3.2-kpc towards the HVC gas at velocity of +224 km/s and NHI=5.2x10^19 cm-2.\nThis gas is in the same region of the sky as complex WE (Wakker 2001), but at\nhigher velocities. The non-detection of CaII K absorption sets a lower distance\nof 3.2-kpc towards the HVC, which is unsurprising if this feature is indeed\nrelated to the Magellanic System.", "Using the path-integral Monte Carlo method, we calculate the energy to form\nsingle and pair vacancies and interstitials in a two-dimensional Wigner crystal\nof electrons. We confirm that the lowest-lying energy defects of a 2D electron\nWigner crystal are interstitials, with a creation energy roughly 2/3 that of a\nvacancy. The formation energy of the defects goes to zero near melting,\nsuggesting that point defects might mediate the melting process. In addition,\nwe find that the interaction between defects is strongly attractive, so that\nmost defects will exist as bound pairs.", "We propose a simple, versatile and fast computational model tounderstand the\ndeviations from the well-known Kolmogorov-Johnson-Mehl-Avrami kinetic\ntheoryfound in metal recrystallization and amorphous semiconductor\ncrystallization. Our model describes in detail the kinetics of the\ntransformation and the grain size distribution of the product material, and is\nin good agreement with the available experimental data. Other morphological and\nkinetic features amenable of experimental observation are outlined, suggesting\nnew directions for further validation of the model.", "Context: The mass-loss rate is a key parameter of massive stars. Adequate\nstellar atmosphere models are required for spectral analyses and mass-loss\ndeterminations. Present models can only account for the inhomogeneity of\nstellar winds in the approximation of small-scale structures that are optically\nthin. This treatment of ``microclumping'' has led to reducing empirical\nmass-loss rates by factors of two and more. Aims: Stellar wind clumps can be\noptically thick in spectral lines. We investigate how this ``macroclumping''\nimpacts on empirical mass-loss rates. Methods: The Potsdam Wolf-Rayet (PoWR)\nmodel atmosphere code is generalized in the ``formal integral'' to account for\nclumps that are not necessarily optically thin. Results: Optically thick clumps\nreduce the effective opacity. This has a pronounced effect on the emergent\nspectrum. Our modeling for the O-type supergiant zeta Puppis reveals that the\noptically thin H-alpha line is not affected by wind porosity, but that the PV\nresonance doublet becomes significantly weaker when macroclumping is taken into\naccount. The reported discrepancies between resonance-line and\nrecombination-line diagnostics can be resolved entirely with the macroclumping\nmodeling without downward revision of the mass-loss rate. Conclusions:\nMass-loss rates inferred from optically thin emission, such as the H-alpha line\nin O stars, are not influenced by macroclumping. The strength of optically\nthick lines, however, is reduced because of the porosity effects. Therefore,\nneglecting the porosity in stellar wind modeling can lead to underestimating\nempirical mass-loss rates.", "Photonic band structure of metal-dielectric and semiconductor-dielectric\nlayered structures are studied in the presence of a strong absorption. It is\nshown that absorption can enlarge some gaps by as much as 50%.", "The Gamma-Ray Large Area Space Telescope (GLAST), scheduled to be launched in\nfall 2007, is the next generation satellite for high-energy gamma-ray\nastronomy. The Large Area Telescope (LAT),\n  GLAST main instrument, with a wide field of view (> 2 sr), a large effective\narea (> 8000 cm^2 at 1 GeV) and 20 MeV - 300 GeV energy range, will provide\nexcellent high energy gamma-ray observations for Dark Matter searches. In this\npaper we examine the potential of the LAT to detect gamma-rays coming from\nWIMPS annihilation in the context of supersymmetry. As an example, two search\nregions are investigated: the galactic center and the galactic satellites.", "The recently updated data of the twin kilohertz quasi-periodic oscillations\n(kHz QPOs) in the neutron star low-mass X-ray binaries are analyzed. The\npower-law fitting $\\nu_{1}=a(\\nu_{2}/1000)^{b}$ and linear fitting\n$\\nu_{2}=A\\nu_{1}+B$ are applied, individually, to the data points of four Z\nsources (GX 17+2, GX 340+0, GX 5-1 and Sco X-1) and four Atoll sources (4U\n0614+09, 4U 1608-52, 4U 1636-53 and 4U 1728-34). The $\\chi^{2}$-tests show that\nthe power-law correlation and linear correlation both can fit data well.\nMoreover, the comparisons between the data and the theoretical models for kHz\nQPOs are discussed.", "I contrast the profound differences in the ways in which algebra and analysis\nare used in physics. In particular I discuss the fascinating phenomenon that\ntheoretical physicists devote almost all their efforts to algebraic problems\neven though all problems of experimental interest require some methods of\nanalysis.", "We present semi-analytical constraint on the amount of dark matter in the\nmerging bullet galaxy cluster using the classical Local Group timing arguments.\nWe consider particle orbits in potential models which fit the lensing data.\n{\\it Marginally consistent} CDM models in Newtonian gravity are found with a\ntotal mass M_{CDM} = 1 x 10^{15}Msun of Cold DM: the bullet subhalo can move\nwith V_{DM}=3000km/s, and the \"bullet\" X-ray gas can move with\nV_{gas}=4200km/s. These are nearly the {\\it maximum speeds} that are\naccelerable by the gravity of two truncated CDM halos in a Hubble time even\nwithout the ram pressure. Consistency breaks down if one adopts higher end of\nthe error bars for the bullet gas speed (5000-5400km/s), and the bullet gas\nwould not be bound by the sub-cluster halo for the Hubble time. Models with\nV_{DM}~ 4500km/s ~ V_{gas} would invoke unrealistic large amount M_{CDM}=7x\n10^{15}Msun of CDM for a cluster containing only ~ 10^{14}Msun of gas. Our\nresults are generalisable beyond General Relativity, e.g., a speed of\n$4500\\kms$ is easily obtained in the relativistic MONDian lensing model of\nAngus et al. (2007). However, MONDian model with little hot dark matter\n$M_{HDM} \\le 0.6\\times 10^{15}\\msun$ and CDM model with a small halo mass $\\le\n1\\times 10^{15}\\msun$ are barely consistent with lensing and velocity data.", "Two stages of quantum spinodal decomposition is proposed and analyzed for\nthis highly non-equilibrium process. Both time and spatial scales for the\nprocess are found. Qualitative agreement with existing data is found. Some\ncases the agreements are quantitative. Further experimental verifications are\nindicated.", "We investigate an optically driven quantum computer based on electric dipole\ntransitions within coupled single-electron quantum dots. Our quantum register\nconsists of a freestanding n-type pillar containing a series of pair wise\ncoupled asymmetric quantum dots, each with a slightly different energy\nstructure, and with grounding leads at the top and bottom of the pillar.\nAsymmetric quantum wells confine electrons along the pillar axis and a\nnegatively biased gate wrapped around the center of the pillar allows for\nelectrostatic confinement in the radial direction. We self-consistently solve\ncoupled Schrodinger and Poisson equations and develop a design for a\nthree-qubit quantum register. Our results indicate that a single gate electrode\ncan be used to localize a single electron in each of the quantum dots. Adjacent\ndots are strongly coupled by electric dipole-dipole interactions arising from\nthe dot asymmetry, thus enabling rapid computation rates. The dots are tailored\nto minimize dephasing due to spontaneous emission and phonon scattering and to\nmaximize the number of computation cycles. The design is scalable to a large\nnumber of qubits.", "We consider a process in which there are two types of particles, A and B, on\nan infinite one-dimensional lattice. The particles hop to their adjacent sites,\nlike the totally asymmetric exclusion process (ASEP), and have also the\nfollowing interactions: A+B -> B+B and B+A -> B+B, all occur with equal rate.\nWe study this process by imposing four boundary conditions on ASEP master\nequation. It is shown that this model is integrable, in the sense that its\nN-particle S-matrix is factorized into a product of two-particle S-matrices\nand, more importantly, the two-particle S-matrix satisfy quantum Yang-Baxter\nequation. Using coordinate Bethe-ansatz, the N-particle wavefunctions and the\ntwo-particle conditional probabilities are found exactly.\n  Further, by imposing four reasonable physical conditions on two-species\ndiffusion-reaction processes (where the most important ones are the equality of\nthe reaction rates and the conservation of the number of particles in each\nreaction), we show that among the 4096 types of the interactions which have\nthese properties and can be modeled by a master equation and an appropriate set\nof boundary conditions, there are only 28 independent interactions which are\nintegrable. We find all these interactions and also their corresponding wave\nfunctions. Some of these may be new solutions of quantum Yang-Baxter equation.", "OH 231.8+4.2 is a well studied preplanetary nebula (pPN) around a binary\nstellar system that shows a remarkable bipolar outflow. To study the structure\nand kinematics of the inner 10-80 AU nebular regions we performed\nhigh-resolution observations of the H$_2$O 6$_{1,6}$--5$_{2,3}$ and $^{28}$SiO\n$v$=2, $J$=1--0 maser emissions with the Very Long Baseline Array. The absolute\nposition of both emission distributions were recovered using the phase\nreferencing technique, and accurately registered in HST optical images. H$_2$O\nmaser clumps are found to be distributed in two areas of 20 mas in size\nspatially displaced by $\\sim$60 milli-arcseconds along an axis oriented nearly\nnorth-south. SiO masers are tentatively found to be placed between the two\nH$_2$O maser emitting regions, probably indicating the position of the Mira\ncomponent of the system. The SiO maser emission traces an inner equatorial\ncomponent with a diameter of 12 AU, probably a disk rotating around the M-type\nstar. Outwards, we detect in the H$_2$O data a pair of polar caps, separated by\n80 AU. We believe that the inner regions of the nebula probably have been\naltered by the presence of the companion, leading to an equator-to-pole density\ncontrast that may explain the lack of H$_2$O masers and strong SiO maser\nemission in the denser, equatorial regions.", "We investigate the possibility of discriminating between Modified Newtonian\nDynamics (MOND) and Newtonian gravity with dark matter, by studying the\nvertical dynamics of disk galaxies. We consider models with the same circular\nvelocity in the equatorial plane (purely baryonic disks in MOND and the same\ndisks in Newtonian gravity embedded in spherical dark matter haloes), and we\nconstruct their intrinsic and projected kinematical fields by solving the Jeans\nequations under the assumption of a two-integral distribution function. We\nfound that the vertical velocity dispersion of deep-MOND disks can be much\nlarger than in the equivalent spherical Newtonian models. However, in the more\nrealistic case of high-surface density disks this effect is significantly\nreduced, casting doubts on the possibility of discriminating between MOND and\nNewtonian gravity with dark matter by using current observations.", "Multifrequency VLBA observations of the final group of ten objects in a\nsample of FIRST-based compact steep spectrum (CSS) sources are presented. The\nsample was selected to investigate whether objects of this kind could be relics\nof radio-loud AGNs switched off at very early stages of their evolution or\npossibly to indicate intermittent activity. Initial observations were made\nusing MERLIN at 5 GHz. The sources have now been observed with the VLBA at 1.7,\n5 and 8.4 GHz in a snapshot mode with phase-referencing. The resulting maps are\npresented along with unpublished 8.4-GHz VLA images of five sources. Some of\nthe sources discussed here show a complex radio morphology and therefore a\ncomplicated past that, in some cases, might indicate intermittent activity. One\nof the sources studied - 1045+352 - is known as a powerful radio and\ninfrared-luminous broad absorption line (BAL) quasar. It is a young CSS object\nwhose asymmetric two-sided morphology on a scale of several hundred parsecs,\nextending in two different directions, may suggest intermittent activity. The\nyoung age and compact structure of 1045+352 is consistent with the evolution\nscenario of BAL quasars. It has also been confirmed that the submillimetre flux\nof 1045+352 can be seriously contaminated by synchrotron emission.", "The hydrodynamic equations of an ideal fluid formed by a dilute quantum gas\nin a parabolic trapping potential are studied analytically and numerically. Due\nto the appearance of internal modes in the fluid stratified by the trapping\npotential, the spectrum of low-lying modes is found to be dense in the\nhigh-temperature limit, with an infinitely degenerate set of zero-frequency\nmodes. The spectrum for Bose-fluids and Fermi-fluids is obtained and discussed.", "Exploiting the spin resonance of two-dimensional (2D) electrons in SiGe/Si\nquantum wells we determine the carrier-density-dependence of the magnetic\nsusceptibility. Assuming weak interaction we evaluate the density of states at\nthe Fermi level D(E_F), and the screening wave vector, q_TF. Both are constant\nat higher carrier densities n, as for an ideal 2D carrier gas. For n < 3e11\ncm-2, they decrease and extrapolate to zero at n = 7e10 cm-2. Calculating the\nmobility from q_TF yields good agreement with experimental values justifying\nthe approach. The decrease in D(E_F) is explained by potential fluctuations\nwhich lead to tail states that make screening less efficient and - in a\npositive feedback - cause an increase of the potential fluctuations. Even in\nour high mobility samples the fluctuations exceed the electron-electron\ninteraction leading to the formation of puddles of mobile carriers with at\nleast 1 micrometer diameter.", "The critical behavior of collective modes and the collapsing dynamics of\ntrapped Bose-Einstein condensates with attractive interactions are studied\nanalytically and numerically. The time scales of these dynamics both below and\nabove the critical point of the collapse are found to obey power laws with a\nsingle parameter of N/N_c - 1, where N is the number of condensate atoms and\nN_c is the critical number. The collapsing condensate eventually undergoes\nrapid implosion, which occurs several times intermittently, and then the\nimplosion turns to an explosion. The release energy of the explosion is found\nto be proportional to the square of the interaction strength, inversely\nproportional to the three-body recombination rate, and independent of the\nnumber of condensate atoms and the trap frequency.", "We present photometric detections of dust emission at 850 and 450 micron\naround the pre-main sequence M1 dwarf TWA 7 using the SCUBA camera on the James\nClerk Maxwell Telescope. These data confirm the presence of a cold dust disk\naround TWA 7, a member of the TW Hydrae Association. Based on the 850 micron\nflux, we estimate the mass of the disk to be 18 lunar masses (0.2 Earth masses)\nassuming a mass opacity of 1.7 cm^2/g with a temperature of 45 K. This makes\nthe TWA 7 disk (d=55 pc) an order of magnitude more massive than the disk\nreported around AU Microscopii (GL 803), the closest (9.9 pc) debris disk\ndetected around an M dwarf. This is consistent with TWA 7 being slightly\nyounger than AU Mic. We find that the mid-IR and submillimeter data require the\ndisk to be comprised of dust at a range of temperatures. A model in which the\ndust is at a single radius from the star, with a range of temperatures\naccording to grain size, is as effective at fitting the emission spectrum as a\nmodel in which the dust is of uniform size, but has a range of temperatures\naccording to distance. We discuss this disk in the context of known disks in\nthe TW Hydrae Association and around low-mass stars; a comparison of masses of\ndisks in the TWA reveals no trend in mass or evolutionary state (gas-rich vs.\ndebris) as a function of spectral type.", "Anomalously high generation efficiency of coherent higher field-harmonics in\ncollisions between {\\em oppositely charged particles} in the field of\nfemtosecond lasers is predicted. This is based on rigorous numerical solutions\nof a quantum kinetic equation for dense laser plasmas which overcomes\nlimitations of previous investigations.", "We study the kinetics of spin coherence of optically excited electrons in an\nundoped insulating ZnSe/Zn$_{1-x}$Cd$_x$Se quantum well under moderate magnetic\nfields in the Voigt configuration. After clarifying the optical coherence and\nthe spin coherence, we build the kinetic Bloch equations and calculate\ndephasing and relaxation kinetics of laser pulse excited plasma due to\nstatically screened Coulomb scattering and electron hole spin exchange. We find\nthat the Coulomb scattering can not cause the spin dephasing, and that the\nelectron-hole spin exchange is the main mechanism of the spin decoherence.\nMoreover the beat frequency in the Faraday rotation angle is determined mainly\nby the Zeeman splitting, red shifted by the Coulomb scattering and the electron\nhole spin exchange. Our numerical results are in agreement with experiment\nfindings. A possible scenario for the contribution of electron-hole spin\nexchange to the spin dephasing of the $n$-doped material is also proposed.", "We present the results of a deep optical-near-infrared multi-epoch survey\ncovering 2.5 square degrees of the Pleiades open star cluster to search for new\nvery-low-mass brown dwarf members. A significant (~ 5 year) epoch difference\nexists between the optical (CFH12k I-, Z-band) and near infrared (UKIRT WFCAM\nJ-band) observations. We construct I,I-Z and Z,Z-J colour magnitude diagrams to\nselect candidate cluster members. Proper motions are computed for all candidate\nmembers and compared to the background field objects to further refine the\nsample. We recover all known cluster members within the area of our survey. In\naddition, we have discovered 9 new candidate brown dwarf cluster members. The 7\nfaintest candidates have red Z-J colours and show blue near-infrared colours.\nThese are consistent with being L and T-type Pleiads. Theoretical models\npredict their masses to be around 11 Jupiter masses.\n  There is 1 errata for this paper", "We introduce a class of multifractal processes, referred to as Multifractal\nRandom Walks (MRWs). To our knowledge, it is the first multifractal processes\nwith continuous dilation invariance properties and stationary increments. MRWs\nare very attractive alternative processes to classical cascade-like\nmultifractal models since they do not involve any particular scale ratio. The\nMRWs are indexed by few parameters that are shown to control in a very direct\nway the multifractal spectrum and the correlation structure of the increments.\nWe briefly explain how, in the same way, one can build stationary multifractal\nprocesses or positive random measures.", "We present new predictions for the galaxy three-point correlation function\n(3PCF) using high-resolution dissipationless cosmological simulations of a flat\nLCDM Universe which resolve galaxy-size halos and subhalos. We create realistic\nmock galaxy catalogs by assigning luminosities and colors to dark matter halos\nand subhalos, and we measure the reduced 3PCF as a function of luminosity and\ncolor in both real and redshift space. As galaxy luminosity and color are\nvaried, we find small differences in the amplitude and shape dependence of the\nreduced 3PCF, at a level qualitatively consistent with recent measurements from\nthe SDSS and 2dFGRS. We confirm that discrepancies between previous 3PCF\nmeasurements can be explained in part by differences in binning choices. We\nexplore the degree to which a simple local bias model can fit the simulated\n3PCF. The agreement between the model predictions and galaxy 3PCF measurements\nlends further credence to the straightforward association of galaxies with CDM\nhalos and subhalos.", "Context: How planet properties depend on stellar mass is a key diagnostic of\nplanetary formation mechanisms. Aims: This motivates planet searches around\nstars which are significantly more massive or less massive than the Sun, and in\nparticular our radial velocity search for planets around very-low mass stars.\nMethods: As part of that program, we obtained measurements of GJ 674, an M2.5\ndwarf at d=4.5 pc, which have a dispersion much in excess of their internal\nerrors. An intensive observing campaign demonstrates that the excess dispersion\nis due to two superimposed coherent signals, with periods of 4.69 and 35 days.\nResults: These data are well described by a 2-planet Keplerian model where each\nplanet has a ~11 Mearth minimum mass. A careful analysis of the (low level)\nmagnetic activity of GJ 674 however demonstrates that the 35-day period\ncoincides with the stellar rotation period. This signal therefore originates in\na spot inhomogeneity modulated by stellar rotation. The 4.69-day signal on the\nother hand is caused by a bona-fide planet, GJ 674b. Conclusion: Its detection\nadds to the growing number of Neptune-mass planets around M-dwarfs, and\nreinforces the emerging conclusion that this mass domain is much more populated\nthan the jovian mass range. We discuss the metallicity distributions of M dwarf\nwith and without planets and find a low 11% probability that they are drawn\nfrom the same parent distribution. Moreover, we find tentative evidence that\nthe host star metallicity correlates with the total mass of their planetary\nsystem.", "Optical reflection measurements within the highly conducting (a,b)-plane of\nthe organic metal (BEDT-TTF)_4[Ni(dto)_2] reveal the gradual development of a\nsharp feature at around 200 cm as the temperature is reduced below 150 K. Below\nthis frequency a narrow Drude-like response is observed which accounts for the\nmetallic behavior. Since de Haas-von Alphen oscillations at low temperatures\nconfirm band structure calculations of bands crossing the Fermi energy, we\nassign the observed behavior to a two-dimensional metallic state in the\nproximity of a correlation induced metal-insulator transition.", "Suzaku observations of two hard X-ray (> 10 keV) selected nearby Seyfert 2\ngalaxies are presented. Both sources were clearly detected with the PIN Hard\nX-ray Detector up to several tens of keV, allowing for a fairly good\ncharacterization of the broad band X-ray continuum. Both sources are heavily\nobscured, one of which (NGC 5728) being Compton thick, while at lower energies\nthe shape and intensity of the scattered/reflected continuum is very different.\nStrong iron Kalpha lines are detected in both sources. There are also hints for\nthe presence of a broad relativistic iron line in NGC 4992.", "The domain growth processes originating from noise-induced nonequilibrium\nphase transitions are analyzed, both for non-conserved and conserved dynamics.\nThe existence of a dynamical scaling regime is established in the two cases,\nand the corresponding growth laws are determined. The resulting universal\ndynamical scaling scenarios are those of Allen-Cahn and Lifshitz-Slyozov,\nrespectively. Additionally, the effect of noise sources on the behaviour of the\npair correlation function at short distances is studied.", "We present Very Large Array observations at 7 millimeters wavelength that\nresolve the dust emission structure in the disk around the young star TW Hydrae\nat the scale of the ~4 AU (~0.16\") radius inner hole inferred from spectral\nenergy distribution modeling. These high resolution data confirm directly the\npresence of an inner hole in the dust disk and reveal a high brightness ring\nthat we associate with the directly illuminated inner edge of the disk. The\nclearing of the inner disk plausibly results from the dynamical effects of a\ngiant planet in formation. In an appendix, we develop an analytical framework\nfor the interpretation of visibility curves from power-law disk models with\ninner holes.", "We compare theoretical results for the characteristic frequency of the\nRayleigh peak calculated in one-loop order within the field theoretical method\nof the renormalization group theory with experiments and other theoretical\nresults. Our expressions describe the non-asymptotic crossover in temperature,\ndensity and wave vector. In addition we discuss the frequency dependent shear\nviscosity evaluated within the same model and compare our theoretical results\nwith recent experiments in microgravity.", "The rotational motion of an interacting Bose-Einstein condensate confined by\na harmonic trap is investigated by solving the hydrodynamic equations of\nsuperfluids, with the irrotationality constraint for the velocity field. We\npoint out the occurrence of an overcritical branch where the system can rotate\nwith angular velocity larger than the oscillator frequencies. We show that in\nthe case of isotropic trapping the system exhibits a bifurcation from an\naxisymmetric to a triaxial configuration, as a consequence of the interatomic\nforces. The dynamical stability of the rotational motion with respect to the\ndipole and quadrupole oscillations is explicitly discussed.", "Nonlinear hopping absorption of ultrasound and electromagnetic waves in\namorphous and doped semiconductors is considered. It is shown that even at low\namplitudes of the electric (or acoustic) field the nonlinear corrections to the\nrelaxational absorption appear anomalously large. The physical reason for such\nbehavior is that the nonlinear contribution is dominated by a small group of\nclose impurity pairs having one electron per pair. Since the group is small, it\nis strongly influenced by the field. An external magnetic field strongly\ninfluences the absorption by changing the overlap between the pair components'\nwave functions. It is important that the influence is substantially different\nfor the linear and nonlinear contributions. This property provides an\nadditional tool to extract nonlinear effects.", "The effective dc-conductivity problem of isotropic, two-dimensional (2D),\nthree-component, symmetric, regular composites is considered. A simple cubic\nequation with one free parameter for $\\sigma_{e}(\\sigma_1,\\sigma_2,\\sigma_3)$\nis suggested whose solutions automatically have all the exactly known\nproperties of that function. Numerical calculations on four different\nsymmetric, isotropic, 2D, three-component, regular structures show a\nnon-universal behavior of $\\sigma_{e}(\\sigma_1,\\sigma_2,\\sigma_3)$ with an\nessential dependence on micro-structural details, in contrast with the\nanalogous two-component problem. The applicability of the cubic equation to\nthese structures is discussed. An extension of that equation to the description\nof other types of 2D three-component structures is suggested, including the\ncase of random structures.\n  Pacs: 72.15.Eb, 72.80.Tm, 61.50.Ah", "A particle in a random potential with logarithmic correlations in dimensions\n$d=1,2$ is shown to undergo a dynamical transition at $T_{dyn}>0$. In $d=1$\nexact results demonstrate that $T_{dyn}=T_c$, the static glass transition\ntemperature, and that the dynamical exponent changes from $z(T)=2 + 2\n(T_c/T)^2$ at high temperature to $z(T)= 4 T_c/T$ in the glass phase. The same\nformulae are argued to hold in $d=2$. Dynamical freezing is also predicted in\nthe 2D random gauge XY model and related systems. In $d=1$ a mapping between\ndynamics and statics is unveiled and freezing involves barriers as well as\nvalleys. Anomalous scaling occurs in the creep dynamics.", "High dispersion near-infrared spectra have been taken of seven\nhighly-evolved, variable, intermediate-mass (4-6 Msun) AGB stars in the LMC and\nSMC in order to look for C, N and O variations that are expected to arise from\nthird dredge-up and hot-bottom burning. The pulsation of the objects has been\nmodelled, yielding stellar masses, and spectral synthesis calculations have\nbeen performed in order to derive abundances from the observed spectra. For two\nstars, abundances of C, N, O, Na, Al, Ti, Sc and Fe were derived and compared\nwith the abundances predicted by detailed AGB models. Both stars show very\nlarge N enhancements and C deficiencies. These results provide the first\nobservational confirmation of the long-predicted production of primary nitrogen\nby the combination of third dredge-up and hot-bottom burning in\nintermediate-mass AGB stars. It was not possible to derive abundances for the\nremaining five stars: three were too cool to model, while another two had\nstrong shocks in their atmospheres which caused strong emission to fill the\nline cores and made abundance determination impossible. The latter occurrence\nallows us to predict the pulsation phase interval during which observations\nshould be made if successful abundance analysis is to be possible.", "[Abridged] We present an analysis of the scaling relations between X-ray\nproperties and Sunyaev-Zel'dovich (SZ) parameters for a sample of 24 X-ray\nluminous galaxy clusters observed with Chandra and with measured SZ effect.\nThese objects are in the redshift range 0.14--0.82 and have X-ray bolometric\nluminosity L>10^45 erg/s. We perform a spatially resolved spectral analysis and\nrecover the density, temperature and pressure profiles of the ICM, just relying\non the spherical symmetry of the cluster and the hydrostatic equilibrium\nhypothesis. We observe that the correlations among X-ray quantities only are in\nagreement with previous results obtained for samples of high-z X-ray luminous\ngalaxy clusters. On the relations involving SZ quantities, we obtain that they\ncorrelate with the gas temperature with a logarithmic slope significantly\nlarger than the predicted value from the self-similar model. The measured\nscatter indicates, however, that the central Compton parameter y_0 is a proxy\nof the gas temperature at the same level of other X-ray quantities like\nluminosity. Our results on the X-ray and SZ scaling relations show a tension\nbetween the quantities more related to the global energy of the system (e.g.\ngas temperature, gravitating mass) and the indicators of the structure of the\nICM (e.g. gas density profile, central Compton parameter y_0), showing the most\nsignificant deviations from the values of the slope predicted from the\nself-similar model in the L-T, L-M_{tot}, M_{gas}-T, y_0-T relations. When the\nslope is fixed to the self-similar value, these relations consistently show a\nnegative evolution suggesting a scenario in which the ICM at higher redshift\nhas lower both X-ray luminosity and pressure in the central regions than the\nexpectations from self-similar model.", "The point-particle-like Hamiltonian of a biaxial spin particle with external\nmagnetic field along the hard axis is obtained in terms of the potential field\ndescription of spin systems with exact spin-coordinate correspondence. The\nZeeman energy term turns out to be an effective gauge potential which leads to\na nonintegrable pha se of the Euclidean Feynman propagator.\n  The phase interference between clockwise and anticlockwise under barrier\npropagations is recognized explicitly as the Aharonov-Bohm effect. An\nadditional phase which is significant for quantum phase interference is\ndiscovered with the quantum theory of spin systems besides the known phase\nobtained with the semiclassical treatment of spin. We also show the energ y\ndependence of the effect and obtain the tunneling splitting at excited states\nwith the help of periodic instantons.", "We comment on the presence of a bimodality in the distribution of delay time\nbetween the formation of the progenitors and their explosion as type Ia SNe.\nTwo \"flavors\" of such bimodality are present in the literature: a \"weak\"\nbimodality, in which type Ia SNe must explode from both young and old\nprogenitors, and a \"strong\" bimodality, in which about half of the systems\nexplode within 10^8 years from formation. The \"weak\" bimodality is\nobservationally based on the dependence of the rates with the host galaxy SFR,\nwhile the \"strong\" one on the different rates in radio-loud and radio-quiet\nearly-type galaxies. We review the evidence for these bimodalities. Finally, we\nestimate the fraction of SNe which are missed by optical and near-IR searches\nbecause of dust extinction in massive starbursts.", "[Abridged] We present time-series optical photometry of five new CVs\nidentified by the Hamburg Quasar Survey. The eclipses observed in HS 0129+2933,\nHS 0220+0603, and HS 0455+8315 provided very accurate orbital periods of\n3.35129827(65), 3.58098501(34), and 3.56937674(26) h, respectively. HS\n0805+3822 shows grazing eclipses and has a likely orbital period of 3.2169(2)\nh. Time-resolved optical spectroscopy of the new CVs (with the exception of HS\n0805+3822) is also presented. Radial velocity studies provided an orbital\nperiod of 3.55 h for HS 1813+6122, which allowed us to identify the observed\nphotometric signal at 3.39 h as a negative superhump wave. The spectroscopic\nbehaviour clearly identifies these new CVs as new SW Sextantis stars. These new\nadditions increase the number of known SW Sex stars to 35. Almost 40 per cent\nof the total SW Sex population do not show eclipses, invalidating the\nrequirement of eclipses as a defining characteristic of the class and the\nmodels based on a high orbital inclination geometry alone. On the other hand,\nthe predominance of orbital periods in the narrow 3-4.5 h range is becoming\nmore pronounced. In fact, almost half the CVs which populate the 3-4.5 h period\ninterval are definite members of the class. These statistics are confirmed by\nour results from the Hamburg Quasar Survey CVs. Remarkably, 54 per cent of the\nHamburg nova-like variables have been identified as SW Sex stars with orbital\nperiods in the 3-4.5 h range. The observation of this pile-up of systems close\nto the upper boundary of the period gap is difficult to reconcile with the\nstandard theory of CV evolution, as the SW Sex stars are believed to have the\nhighest mass transfer rates among CVs. Finally, we review the full range of\ncommon properties that the SW Sex stars exhibit.", "We present a model of a cw atom laser based on a system of coupled GP\nequations. The model incorporates continuous Raman outcoupling, pumping and\nthree-body recombination. The outcoupled field has minimal atomic density\nfluctuations and is locally monochromatic.", "We present the results of high precision measurements of the thermal\nexpansion of the sintered SiC, SiC-100, intended for use in cryogenic\nspace-telescopes, in which minimization of thermal deformation of the mirror is\ncritical and precise information of the thermal expansion is needed for the\ntelescope design. The temperature range of the measurements extends from room\ntemperature down to $\\sim$ 10 K. Three samples, #1, #2, and #3 were\nmanufactured from blocks of SiC produced in different lots. The thermal\nexpansion of the samples was measured with a cryogenic dilatometer, consisting\nof a laser interferometer, a cryostat, and a mechanical cooler. The typical\nthermal expansion curve is presented using the 8th order polynomial of the\ntemperature. For the three samples, the coefficients of thermal expansion\n(CTE), $\\bar{\\alpha}_{#1}$, $\\bar{\\alpha}_{#2}$, and $\\bar{\\alpha}_{#3}$ were\nderived for temperatures between 293 K and 10 K. The average and the dispersion\n(1 $\\sigma$ rms) of these three CTEs are 0.816 and 0.002 ($\\times 10^{-6}$/K),\nrespectively. No significant difference was detected in the CTE of the three\nsamples from the different lots. Neither inhomogeneity nor anisotropy of the\nCTE was observed. Based on the obtained CTE dispersion, we performed an\nfinite-element-method (FEM) analysis of the thermal deformation of a 3.5 m\ndiameter cryogenic mirror made of six SiC-100 segments. It was shown that the\npresent CTE measurement has a sufficient accuracy well enough for the design of\nthe 3.5 m cryogenic infrared telescope mission, the Space Infrared telescope\nfor Cosmology and Astrophysics (SPICA).", "We present a molecular dynamics study of the collective dynamics of a\nflexible model for the fragile glass-former orthoterphenyl [ S. Mossa, R. Di\nleonardo, G. Ruocco, and M. Sampoli, Phys. Rev. E 62, 612 (2000)]. We study the\nbehavior of the coherent scattering functions, considering the density\nfluctuations of both molecular and phenyl rings centers of mass; moreover we\ndirectly simulate the neutron scattering spectra taking into account both the\ncontributions due to the carbon and hydrogens atoms. We compare our results\nwith the main predictions of the Mode Coupling Theory and with the available\ncoherent neutron scattering experimental data.", "As the likely birthplaces of planets and an essential conduit for the buildup\nof stellar masses, inner disks are of fundamental interest in star and planet\nformation. Studies of the gaseous component of inner disks are of interest\nbecause of their ability to probe the dynamics, physical and chemical\nstructure, and gas content of this region. We review the observational and\ntheoretical developments in this field, highlighting the potential of such\nstudies to, e.g., measure inner disk truncation radii, probe the nature of the\ndisk accretion process, and chart the evolution in the gas content of disks.\nMeasurements of this kind have the potential to provide unique insights on the\nphysical processes governing star and planet formation.", "We present wide-field BVI photometry for about 11,500 stars in the\nlow-metallicity cluster NGC 5466. We have detected the red giant branch bump\nfor the first time, although it is at least 0.2 mag fainter than expected\nrelative to the turnoff. The number of red giants (relative to main sequence\nturnoff stars) is in excellent agreement with stellar models from the\nYonsei-Yale and Teramo groups, and slightly high compared to Victoria-Regina\nmodels. This adds to evidence that an abnormally large ratio of red giant to\nmain-sequence stars is not correlated with cluster metallicity. We discuss\ntheoretical predictions from different research groups and find that the\ninclusion or exclusion of helium diffusion and strong limit Coulomb\ninteractions may be partly responsible.\n  We also examine indicators of dynamical history: the mass function exponent\nand the blue straggler frequency. NGC 5466 has a very shallow mass function,\nconsistent with large mass loss and recently-discovered tidal tails. The blue\nstraggler sample is significantly more centrally concentrated than the HB or\nRGB stars. We see no evidence of an upturn in the blue straggler frequency at\nlarge distances from the center. Dynamical friction timescales indicate that\nthe stragglers should be more concentrated if the cluster's present density\nstructure has existed for most of its history. NGC 5466 also has an unusually\nlow central density compared to clusters of similar luminosity. In spite of\nthis, the specific frequency of blue stragglers that puts it right on the\nfrequency -- cluster M_V relation observed for other clusters.", "We present ground-state calculations for laterally coupled quantum dots\ncontaining 2, 4, and 8 electrons. As our emphasis is on spin effects our\nresults are obtained by applying spin-density functional theory (SDFT). By\nvarying the distance between the centers of the coupled quantum dots, the\ntransition from weak to strong coupling situation is realized. For the\n2-electron system we also apply the Heitler-London approximation and analytical\nconcepts to check the reliability of SDFT calculations in this case. In\naddition we discuss the features of the Coulomb staircase of laterally coupled\nquantum dots in the weak and strong coupling regimes in comparison to that of a\ncircular parabolic quantum dot.", "We present a new application of the traditional thermodynamic Bethe ansatz to\nthe spin-1/2 antiferromagnetic uniform Heisenberg chain and derive exact\nnonlinear integral equations for just {\\em two} functions describing the\nelementary excitations. Using this approach the magnetic susceptibility $\\chi$\nand specific heat C versus temperature T are calculated to high accuracy for\n$5\\times10^{-25}\\leq T/J\\leq 5$. The $\\chi(T)$ data agree very well at low T\nwith the asymptotically exact theoretical low-T prediction of S. Lukyanov,\nNucl. Phys. B {\\bf 522}, 533 (1998). The unknown coefficients of the second and\nthird lowest-order logarithmic correction terms in Lukyanov's theory for C(T)\nare estimated from the C(T) data.", "The measurement of the flavor composition of the neutrino fluxes from\nastrophysical sources has been proposed as a method to study not only the\nnature of their emission mechanisms, but also the neutrino fundamental\nproperties. It is however problematic to reconcile these two goals, since a\nsufficiently accurate understanding of the neutrino fluxes at the source is\nneeded to extract information about the physics of neutrino propagation. In\nthis work we discuss critically the expectations for the flavor composition and\nenergy spectrum from different types of astrophysical sources, and comment on\nthe theoretical uncertainties connected to our limited knowledge of their\nstructure.", "Using an electron spin resonance spectrometer covering a wide range of\nfrequency and magnetic field, we have measured the low energy excitations of\nthe S=1/2 tetragonal antiferromagnets, Sr_{2}CuO_{2}Cl_{2} and\nSr_{2}Cu_{3}O_{4}Cl_{2}. Our observation of in-plane energy gaps of order 0.1\nmeV at zero external magnetic field are consistent with a spin wave\ncalculation, which includes several kinds of quantum fluctuations that remove\nfrustration. Results agree with other experiments and with exchange anisotropy\nparameters determined from a five band Hubbard model.", "In view of the recent experiments of O'Hara, et al. on excitons in Cu_2O, we\nexamine the interconversion between the angular-momentum triplet-state excitons\nand the angular-momentum singlet-state excitons by a spin-exchange process\nwhich has been overlooked in the past. We estimate the rate of this\nparticle-conserving mechanism and find a substantially higher value than the\nAuger process considered so far. Based on this idea, we give a possible\nexplanation of the recent experimental observations, and make certain\npredictions, with the most important being that the singlet-state excitons in\nCu_2O is a very serious candidate for exhibiting the phenomenon of\nBose-Einstein condensation.", "The replicated field theory of the random field Ising model involves the\ncouplings of replicas of different indices. The resulting correlation functions\ninvolve a superposition of different types of long distance behaviours. However\nthe $n=0$ limit allows one to discuss the renormalization group properties in\nspite of this phenomenon. The attraction of pairs of replicas is enhanced under\nrenormalization flow and no stable fixed point is found. Consequently an\ninstability occurs in the paramagnetic region, before one reaches the Curie\nline, signalling the onset of replica symmetry breaking.", "We introduce a {\\it lattice} version of the Calogero Sutherland model adapted\nto describe $1/d^2$ pairwise interacting steps with discrete positions on a\nvicinal surface. The configurational free energy is obtained within a transfer\nmatrix method. The full phase diagram for attractive and for repulsive\ninteraction is deduced. For attraction, critical temperatures of faceting\ntransitions are found to depend on step density.", "We present optical and X-ray data for a sample of serendipitous XMM-Newton\nsources that are selected to have 0.5-2 keV vs 2-4.5 keV X-ray hardness ratios\nwhich are harder than the X-ray background. The sources have 2-4.5 keV X-ray\nflux >= 10^-14 cgs, and in this paper we examine a subsample of 42 optically\nbright (r < 21) sources; this subsample is 100 per cent spectroscopically\nidentified. All but one of the optical counterparts are extragalactic, and we\nargue that the single exception, a Galactic M star, is probably a coincidental\nassociation. The X-ray spectra are consistent with heavily absorbed power laws\n(21.8 < log NH < 23.4), and all of them appear to be absorbed AGN. The majority\nof the sources show only narrow emission lines in their optical spectra,\nimplying that they are type-2 AGN. Only a small fraction of the sources (7/42)\nshow broad optical emission lines, and all of these have NH < 10^23 cm^-2. This\nimplies that ratios of X-ray absorption to optical/UV extinction equivalent to\n> 100 times the Galactic gas-to-dust ratio are rare in AGN absorbers (at most a\nfew percent of the population), and may be restricted to broad absorption-line\nQSOs. Seven objects appear to have an additional soft X-ray component in\naddition to the heavily absorbed power law. We consider the implications of our\nresults in the light of the AGN unified scheme. We find that the soft\ncomponents in narrow-line objects are consistent with the unified scheme\nprovided that > 4 per cent of broad-line AGN have ionised absorbers that\nattenuate their soft X-ray flux by >50 per cent. In at least one of the X-ray\nabsorbed, broad-line AGN in our sample the X-ray spectrum requires an ionised\nabsorber, consistent with this picture.", "The temperature and magnetic field dependences of the electronic specific\nheat in the superconducting mixed state as well as the upper critical field\nhave been measured on a (Y,Lu)Ni2B2C series to study the influence of disorder.\nThe electronic specific heat in the vortex state shows deviations from the\nusual gamma(H) proportional to H-law for conventional superconductors for all\nsamples resulting in a disorder dependent negative curvature of gamma\nproportional to H sup(1-beta). For samples with disorder at the R site beta and\nthe positive curvature exponent alpha of H sub(c2) are reduced but alpha, beta\nremain always positive, as distinct from much stronger disorder due to Pt\nsubstions at the Ni site where alpha, beta rapidly tend to 0. Alpha shows a\nminimum at equal Y and Lu concentration. H sub(c2)(00, T sub(c), the curvatures\nof H sub(c2) and gamma(h), as well as the normal state Sommerfeld constant\ngamma sub(N) are reduced similarly.", "Present expansion stage of the universe is believed to be mainly governed by\nthe cosmological constant, collisionless dark matter and baryonic matter. The\nlatter two components are often modeled as zero-pressure fluids. In our\nprevious work we have shown that to the second-order cosmological\nperturbations, the relativistic equations of the zero-pressure, irrotational,\nmulti-component fluids in a spatially near flat background effectively coincide\nwith the Newtonian equations. As the Newtonian equations only have quadratic\norder nonlinearity, it is practically interesting to derive the potential\nthird-order perturbation terms in general relativistic treatment which\ncorrespond to pure general relativistic corrections. Here, we present pure\ngeneral relativistic correction terms appearing in the third-order\nperturbations of the multi-component zero-pressure fluids. We show that, as in\na single component situation, the third-order correction terms are quite small\n(~ 5 x10^{-5} smaller compared with the relativistic/Newtonian second-order\nterms) due to the weak level anisotropy of the cosmic microwave background\nradiation. Still, there do exist pure general relativistic correction terms in\nthird-order perturbations which could potentially become important in future\ndevelopment of precision cosmology. We include the cosmological constant in all\nour analyses.", "Extensive Monte Carlo simulations are performed in order to evaluate both the\nlocal ($\\theta_{l}$) and global ($\\theta_{g}$) persistence exponents in the\nZiff-Gulari-Barshad (ZGB) (Phy. Rev. Lett. {\\bf 56}, 2553, (1986)) irreversible\nreaction model. In two dimensions and for the second-order irreversible phase\ntransition (IPT) we find, that both the local and the global persistence\nexhibit power-law behavior with a crossover between two different time regimes.\nOn the other hand, at the first-order IPT, characteristic of the ZGB, active\nsites are short lived and the persistence decays more abruptly, not being clear\nwhether it shows power law behavior or not. In order to analyze universality\nissues, we have also studied another model with absorbing states, the contact\nprocess, and evaluated the local persistence exponent in dimensions from 1 to\n4. A striking apparent {\\it super-universality} is reported: the local\npersistence exponent seems to coincide in both one and two dimensional systems.", "We present ground-based B and R-band color-magnitude diagrams (CMDs),\nreaching the oldest main-sequence turnoffs with good photometric accuracy for\ntwelve fields in the Small Magellanic Cloud (SMC). Our fields, located between\n~1 and ~4 degrees from the center of the galaxy, are situated in different\nparts of the SMC such as the \"Wing'' area, and towards the West and South. In\nthis paper we perform a first analysis of the stellar content in our SMC fields\nthrough comparison with theoretical isochrones and color functions (CFs). We\nfind that the underlying spheroidally distributed population is composed of\nboth intermediate-age and old stars and that its age composition does not show\nstrong galacto-centric gradients. The three fields situated toward the east, in\nthe Wing region, show very active current star formation. However, only in the\neastern field closest to the center do we find an enhancement of recent star\nformation with respect to a constant SFR(t). The fields corresponding to the\nwestern side of the SMC present a much less populated young MS, and the CF\nanalysis indicates that the SFR(t) greatly diminished around 2 Gyr ago in these\nparts. Field smc0057, the closest to the center of the galaxy and located in\nthe southern part, shows recent star formation, while the rest of the southern\nfields present few bright MS stars. The structure of the red clump in all the\nCMDs is consistent with the large amount of intermediate-age stars inferred\nfrom the CMDs and color functions. None of the SMC fields presented here are\ndominated by old stellar populations, a fact that is in agreement with the lack\nof a conspicuous horizontal branch in all these SMC CMDs. This could indicate\nthat a disk population is ruling over a possible old halo in all the observed\nfields.", "Within the internal shock scenario we consider different mechanisms of high\nenergy ($>1$ MeV) photon production inside a Gamma Ray Burst (GRB) fireball and\nderive the expected high energy photon spectra from individual GRBs during the\nprompt phase. The photon spectra of leptonic and hadronic origins are compared\nwithin different sets of parameter regimes. Our results suggest that the high\nenergy emission is dominated by the leptonic component if fraction of shock\nenergy carried by electrons is not very small (e.g. $\\epsilon_e > 10^{-3}$).\nFor very small values of $\\epsilon_e$ the hadronic emission component could be\ncomparable to or even exceed the leptonic component in the GeV-TeV regime.\nHowever, in this case a much larger energy budget of the fireball is required\nto account for the same level of the observed sub-MeV spectrum. The fireballs\nare therefore extremely inefficient in radiation. For a canonical fireball bulk\nLorentz factor (e.g. $\\Gamma=400$), emissions above $\\sim 10$ GeV are\nattenuated by two-photon pair production processes. For a fireball with an even\nhigher Lorentz factor, the cutoff energy is higher, and emissions of 10 TeV -\nPeV due to $\\pi^0$-decay can also escape from the internal shocks. The flux\nlevel is however too low to be detected by current TeV detectors, and these\nphotons also suffer attenuation by external soft photons.", "The abnormally intense radiation due to the uniform rotation of electron\naround the equatorial plane of a dielectric sphere is obtained. It takes place\nwhen the sphere surface is at a specific distance from the electron orbit and\nwhen the Cherenkov condition for electron and the matter of the sphere is\nsatisfied.", "Compton scattering of X-rays in the bulk flow of the accretion column in\nmagnetic cataclysmic variables (mCVs) can significantly shift photon energies.\nWe present Monte Carlo simulations based on a nonlinear algorithm demonstrating\nthe effects of Compton scattering on the H-like, He-like and neutral Fe K alpha\nlines produced in the post-shock region of the accretion column. The peak line\nemissivities of the photons in the post-shock flow are taken into consideration\nand frequency shifts due to Doppler effects are also included. We find that\nline profiles are most distorted by Compton scattering effects in strongly\nmagnetized mCVs with a low white dwarf mass and high mass accretion rate and\nwhich are viewed at an oblique angle with respect to the accretion column. The\nresulting line profiles are most sensitive to the inclination angle. We have\nalso explored the effects of modifying the accretion column width and using a\nrealistic emissivity profile. We find that these do not have a significant\noverall effect on the resulting line profiles. A comparison of our simulated\nline spectra with high resolution Chandra/HETGS observations of the mCV GK Per\nindicates that a wing feature redward of the 6.4 keV line may result from\nCompton recoil near the base of the accretion column.", "With the release of the 2MASS All-Sky Point Source Catalog, stellar fluxes\nfrom 2MASS are used to remove the contribution due to Galactic stars from the\nintensity measured by DIRBE in 40 new regions in the North and South Galactic\npolar caps. After subtracting the interplanetary and Galactic foregrounds, a\nconsistent residual intensity of 14.69 +/- 4.49 kJy/sr at 2.2 microns is found.\nAllowing for a constant calibration factor between the DIRBE 3.5 microns and\nthe 2MASS 2.2 microns fluxes, a similar analysis leaves a residual intensity of\n15.62 +/- 3.34 kJy/sr at 3.5 microns. The intercepts of the DIRBE minus 2MASS\ncorrelation at 1.25 microns show more scatter and are a smaller fraction of the\nforeground, leading to a still weak limit on the CIRB of 8.88 +/- 6.26 kJy/sr\n(1 sigma).", "We study the field theories for pinned elastic systems at equilibrium and at\ndepinning. Their $\\beta$-functions differ to two loops by novel ``anomalous''\nterms. At equilibrium we find a roughness $\\zeta=0.20829804 \\epsilon + 0.006858\n\\epsilon^2$ (random bond), $\\zeta=\\epsilon/3$ (random field). At depinning we\nprove two-loop renormalizability and that random field attracts shorter range\ndisorder. We find $\\zeta=\\frac{\\epsilon}{3}(1 + 0.14331 \\epsilon)$,\n$\\epsilon=4-d$, in violation of the conjecture $\\zeta=\\epsilon/3$, solving the\ndiscrepancy with simulations. For long range elasticity\n$\\zeta=\\frac{\\epsilon}{3}(1 + 0.39735 \\epsilon)$, $\\epsilon=2-d$, much closer\nto the experimental value ($\\approx 0.5$ both for liquid helium contact line\ndepinning and slow crack fronts) than the standard prediction 1/3.", "We offer a new proposal for the Monte Carlo treatment of many-fermion systems\nin continuous space. It is based upon Diffusion Monte Carlo with significant\nmodifications: correlated pairs of random walkers that carry opposite signs;\ndifferent functions ``guide'' walkers of different signs; the Gaussians used\nfor members of a pair are correlated; walkers can cancel so as to conserve\ntheir expected future contributions. We report results for free-fermion systems\nand a fermion fluid with 14 $^3$He atoms, where it proves stable and correct.\nIts computational complexity grows with particle number, but slowly enough to\nmake interesting physics within reach of contemporary computers.", "The most massive elliptical galaxies show a prominent multi-modality in their\nglobular cluster system color distributions. Understanding the mechanisms which\nlead to multiple globular cluster sub-populations is essential for a complete\npicture of massive galaxy formation. By assuming that globular cluster\nformation traces the total star formation and taking into account the radial\nvariations in the composite stellar populations predicted by the Pipino &\nMatteucci (2004) multi-zone photo-chemical evolution code, we compute the\ndistribution of globular cluster properties as a function of galactocentric\nradius. We compare our results to the spectroscopic measurements of globular\nclusters in nearby early-type galaxies by Puzia et al. (2006) and show that the\nobserved multi-modality in globular cluster systems of massive ellipticals can\nbe, at least partly, ascribed to the radial variation in the mix of stellar\npopulations. Our model predicts the presence of a super-metal-rich population\nof globular clusters in the most massive elliptical galaxies, which is in very\ngood agreement with the spectroscopic observations. Furthermore, we investigate\nthe impact of other non-linear mechanisms that shape the metallicity\ndistribution of globular cluster systems, in particular the role of\nmerger-induced globular cluster formation and a non-linear color-metallicity\ntransformation, and discuss their influence in the context of our model\n(abridged)", "We analyze all X-ray timing data on 1E 1207.4-5209 in supernova remnant PKS\n1209-51/52 gathered in 2000-2005, and find a highly stable rotation with\nP=424.130451(4) ms and period derivative of (9.6 +/- 9.4)E-17 s/s. This refutes\nprevious claims of large timing irregularities in these data. In the dipole\nspin-down formalism, the 2-sigma upper limit on period derivative implies an\nenergy loss rate < 1.5E32 ergs/s, surface magnetic field strength B_p < 3.5E11\nG, and characteristic age tau > 24 Myr. This tau exceeds the remnant age by 3\norders of magnitude, requiring that the pulsar was born spinning at its present\nperiod. The X-ray luminosity of 1E 1207.4-5209, L(bol) ~= 2E33 ergs/s at 2 kpc,\nexceeds its spin-down energy loss, implying that L(bol) derives from residual\ncooling, and perhaps partly from accretion of supernova debris. The upper limit\non B_p is small enough to favor the electron cyclotron model for at least one\nof the prominent absorption lines in its soft X-ray spectrum. This is the\nsecond demonstrable case of a pulsar born spinning slowly and with a weak\nB-field, after PSR J1852+0040 in Kesteven 79.", "We study the points of degeneracy (diabolical points) in magnetic molecules\nsuch as Mn_{12}-acetate that have an easy axis of four-fold symmetry. This is\ndone for general magnetic field that need not be oriented along a high-symmetry\ndirection. We develop a perturbative technique that gives the diabolical points\nas the roots of a small number of polynomials in the transverse component of\nthe magnetic field and the fourth order basal plane anisotropy. In terms of\nthese roots we obtain approximate analytic formulas that apply to any system\nwith total spin S \\le 10. The analytic results are found to compare reasonably\nwell with exact numerical diagonalization for the case of Mn12. In addition,\nthe perturbation theory shows that the diabolical points may be indexed by the\nmagnetic quantum numbers of the levels involved, even at large transverse\nfields. Certain points of degeneracy are found to be mergers (or near mergers)\nof two or three diabolical points beacuse of the symmetry of the problem.", "Carrier-induced ferromagnetism has been observed in several (III,Mn)V\nsemiconductors. We review the theoretical picture of these ferromagnetic\nsemiconductors that emerges from a model with kinetic-exchange coupling between\nlocalized Mn spins and valence-band carriers. We discuss the applicability of\nthis model, the validity of a mean-field approximation for its interaction term\nwidely used in the literature, and validity limits for the simpler RKKY model\nin which only Mn spins appear explicitly. Our conclusions are based in part on\nour analysis of the dependence of the system's elementary spin excitations on\ncarrier density and exchange-coupling strength. The analogy between this system\nand spin-model ferrimagnets is explored. Finally, we list several extensions of\nthis model that can be important in realistic modeling of specific materials.", "A special limit of an antiferromagnetic XYZ chain was recently shown to\nexhibit interesting bulk as well as surface spin-flop transitions at T=0. Here\nwe provide a complete calculation of the thermodynamics of the bulk transition\nusing a transfer-matrix-renormalization-group (TMRG) method that addresses\ndirectly the thermodynamic limit of quantum spin chains. We also shed some\nlight on certain spinwave anomalies at low temperature predicted earlier by\nJohnson and Bonner.", "We critically examine issues associated with determining the fundamental\nproperties of the black hole and the surrounding accretion disk in an X-ray\nbinary based on modeling the disk X-ray continuum of the source. We base our\nwork mainly on two XMM-Newton observations of GX 339-4, because they provided\nhigh-quality data at low energies (below 1 keV) which are critical for reliably\nmodeling the spectrum of the accretion disk. A key issue examined is the\ndetermination of the so-called \"color correction factor\", which is often\nempirically introduced to account for the deviation of the local disk spectrum\nfrom a blackbody (due to electron scattering). This factor cannot be\npre-determined theoretically because it may vary with, e.g., mass accretion\nrate, among a number of important factors. We follow up on an earlier\nsuggestion to estimate the color correction observationally by modeling the\ndisk spectrum with saturated Compton scattering. We show that the spectra can\nbe fitted well and the approach yields reasonable values for the color\ncorrection factor. For comparison, we have also attempted to fit the spectra\nwith other models. We show that even the high-soft-state continuum (which is\ndominated by the disk emission) cannot be satisfactorily fitted by\nstate-of-the-art disk models. We discuss the implication of the results.", "The physical interpretation of spectropolarimetric observations of lines of\nneutral helium, such as those of the 10830 A multiplet, represents an excellent\nopportunity for investigating the magnetism of plasma structures in the solar\nchromosphere. Here we present a powerful forward modeling and inversion code\nthat permits either to calculate the emergent intensity and polarization for\nany given magnetic field vector or to infer the dynamical and magnetic\nproperties from the observed Stokes profiles. This diagnostic tool is based on\nthe quantum theory of spectral line polarization, which self-consistently\naccounts for the Hanle and Zeeman effects in the most general case of the\nincomplete Paschen-Back effect regime. We also take into account radiative\ntransfer effects. An efficient numerical scheme based on global optimization\nmethods has been applied. Our Stokes inversion code permits a fast and reliable\ndetermination of the global minimum.", "The applicability of time-reversal symmetry to nonlinear optics is discussed,\nboth from macroscopic (Maxwell equations) and microscopic (quantum theoretical)\npoint of view. We find that only spatial operations can be applied for the\nsymmetry classification of nonlinear optical processes in magnetic, in\nparticular antiferromagnetic, materials. An example is given where both\noperations (time reversal and a spatial operation) can yield different results.", "We present the theory for Multiple Energy X-ray Holography (MEXH), using a\nmultipole expansion for the scattered field. We find that light polarization\nplays a crucial role in the reconstruction of the image, and we suggest how to\nuse it in order to eliminate aberration effects. The method we propose is\nalternative to the SWIFT method (scattered-wave--included Fourier transform),\nbut has the advantage that no theoretical calculations are required to redefine\nthe hologram.", "Recent transport experiments have established that two-dimensional electron\nsystems with high-index partial Landau level filling, $\\nu^{*} =\\nu - \\lbrack\n\\nu \\rbrack$, have ground states with broken orientational symmetry. In a\nmean-field theory, the broken symmetry state consists of electron stripes with\nlocal filling factor $\\lbrack \\nu \\rbrack + 1 $, separated by hole stripes with\nfilling factor $\\lbrack \\nu \\rbrack$. We have recently developed a theory of\nthese states in which the electron stripes are treated as one-dimensional\nelectron systems coupled by interactions and described by using a Luttinger\nliquid model. Among other things, this theory predicts non-linearities of\nopposite sign in easy and hard direction resistivities. In this article we\nbriefly review our theory, focusing on its predictions for the dependence of\nnon-linear transport exponents on the separation $d$ between the\ntwo-dimensional electron system and a co-planar screening layer.", "This submission has been withdrawn by arXiv administrators because it is a\nduplicate of 0704.2182.", "The collapsing dynamics of a trapped Bose-Einstein condensate (BEC) with\nattractive interaction are revealed to exhibit two previously unknown\nphenomena. During the collapse, BEC undergoes a series of rapid implosions that\noccur {\\it intermittently} within a very small region. When the sign of the\ninteraction is suddenly switched from repulsive to attractive, e.g., by the\nFeshbach resonance, density fluctuations grow to form various patterns such as\na shell structure.", "The HARPS high-resolution high-accuracy spectrograph is offered to the\nastronomical community since the second half of 2003. Since then, we have been\nusing this instrument for monitoring radial velocities of a large sample of\nSolar-type stars (~1400 stars) in order to search for their possible low-mass\ncompanions. Amongst the goals of our survey, one is to significantly increase\nthe number of detected extra-solar planets in a volume-limited sample to\nimprove our knowledge of their orbital elements distributions and thus obtain\nbetter constraints for planet-formation models.\n  In this paper, we present the HARPS radial-velocity data and orbital\nsolutions for 3 Solar-type stars: HD 100777, HD 190647, and HD 221287. The\nradial-velocity data of HD 100777 is best explained by the presence of a 1.1\nM_Jup planetary companion on a 384--day eccentric orbit (e=0.36). The orbital\nfit obtained for the slightly evolved star HD 190647 reveals the presence of a\nlong-period (P=1038 d) 1.9 M_Jup planetary companion on a moderately eccentric\norbit (e=0.18). HD 221287 is hosting a 3.1 M_Jup planet on a 456--day orbit.\nThe shape of this orbit is not very well constrained because of our non-optimal\ntemporal coverage and because of the presence of abnormally large residuals. We\nfind clues for these large residuals to result from spectral line profile\nvariations probably induced by stellar activity related processes.", "The unusual properties of transition objects (young stars with an optically\nthin inner disc surrounded by an optically thick outer disc) suggest that\nsignificant disc evolution has occured in these systems. We explore the nature\nof these systems by examining their demographics, specifically their stellar\naccretion rates (Mdot) and disc masses (Mdisc) compared to those of accreting T\nTauri stars of comparable age. We find that transition objects in Taurus occupy\na restricted region of the Mdot vs. Mdisc plane. Compared to non-transition\nsingle stars in Taurus, they have stellar accretion rates that are typically\n~10 times lower at the same disc mass and median disc masses ~4 times larger.\nThese properties are anticipated by several proposed planet formation theories\nand suggest that the formation of Jovian mass planets may play a significant\nrole in explaining the origin of at least some transition objects. Considering\ntransition objects as a distinct demographic group among accreting T Tauri\nstars leads to a tighter relationship between disc masses and stellar accretion\nrates, with a slope between the two quantities that is close to the value of\nunity expected in simple theories of disc accretion.", "What is the zero-temperature ordering pattern of a Heisenberg antiferromagnet\nwith large spin length $S$ (and possibly small dilution), on the kagome\nlattice, or others built from corner-sharing triangles and tetrahedra? First, I\nsummarize the uses of effective Hamiltonians to resolve the large ground-state\ndegeneracy, leading to long-range order of the usual kind. Secondly, I discuss\nthe effects of dilution, in particular to {\\it non}-frustration of classical\nground states, in that every simplex of spins is optimally satisfied. Of three\nexplanations for this, the most complete is Moessner-Chalker\nconstraint-counting. Quantum zero-point energy may compete with classical\nexchange energy in a diluted system, creating frustration and enabling a\nspin-glass state. I suggest that the regime of over 97% occupation is\nqualitatively different from the more strongly diluted regime.", "We introduce a new approach to build microscopic engines on the atomic scale\nthat move translationally or rotationally and can perform useful functions such\nas pulling of a cargo. Characteristic of these engines is the possibility to\ndetermine dynamically the directionality of the motion. The approach is based\non the transformation of the fed energy to directed motion through a dynamical\ncompetition between the intrinsic lengths of the moving object and the\nsupporting carrier.", "During accretion a neutron star (NS) is spun up as angular momentum is\ntransported through its surface layers. We study the resulting differentially\nrotating profile, focusing on the impact this has for type I X-ray bursts. The\npredominant viscosity is likely provided by the Tayler-Spruit dynamo. The\nradial and azimuthal magnetic field components have strengths of ~10^5 G and\n~10^10 G, respectively. This leads to nearly uniform rotation at the depths of\ninterest for X-ray bursts. A remaining small shear transmits the accreted\nangular momentum inward to the NS interior. Though this shear gives little\nviscous heating, it can trigger turbulent mixing. Detailed simulations will be\nrequired to fully understand the consequences of mixing, but our models\nillustrate some general features. Mixing has the greatest impact when the\nbuoyancy at the compositional discontinuity between accreted matter and ashes\nis overcome. This occurs at high accretion rates, at low spin frequencies, or\nmay depend on the ashes from the previous burst. We then find two new regimes\nof burning. The first is ignition in a layer containing a mixture of heavier\nelements from the ashes. If ignition occurs at the base of the mixed layer,\nrecurrence times as short as ~5-30 minutes are possible. This may explain the\nshort recurrence time of some bursts, but incomplete burning is still needed to\nexplain these bursts' energetics. When mixing is sufficiently strong, a second\nregime is found where accreted helium mixes deep enough to burn stably,\nquenching X-ray bursts. We speculate that the observed change in X-ray burst\nproperties near one-tenth the Eddington accretion rate is from this mechanism.\nThe carbon-rich material produced by stable helium burning would be important\nfor triggering and fueling superbursts. (abridged)", "We argue that (TMTSF)_2 PF_6 compound under pressure is likely a triplet\nsuperconductor with a vector order parameter d(k) \\equiv (d_a(k) \\neq 0, d_c(k)\n= ?, d_{b'}(k) = 0); |d_a(k)| > |d_c(k)|. It corresponds to an anisotropic spin\nsusceptibility at T=0: \\chi_{b'} = \\chi_0, \\chi_a \\ll \\chi_0, where \\chi_0 is\nits value in a metallic phase. [The spin quantization axis, z, is parallel to a\nso-called b'-axis]. We show that the suggested order parameter explains why the\nupper critical field along the b'-axis exceeds all paramagnetic limiting\nfields, including that for a nonuniform superconducting state, whereas the\nupper critical field along the a-axis (a \\perp b') is limited by the Pauli\nparamagnetic effects [I. J. Lee, M. J. Naughton, G. M. Danner and P. M.\nChaikin, Phys. Rev. Lett. 78, 3555 (1997)]. The triplet order parameter is in\nagreement with the recent Knight shift measurements by I. J. Lee et al. as well\nas with the early results on a destruction of superconductivity by nonmagnetic\nimpurities and on the absence of the Hebel-Slichter peak in the NMR relaxation\nrate.", "We extend the construction of the effective conformal field theory for the\nJain hierarchical fillings proposed in cond-mat/9912287 to the description of a\nquantum Hall fluid at non standard fillings nu=m/(pm+2). The chiral primary\nfields are found by using a procedure which induces twisted boundary conditions\non the m scalar fields; they appear as composite operators of a charged and\nneutral component. The neutral modes describe parafermions and contribute to\nthe ground state wave function with a generalized Pfaffian term. Correlators of\nNe electrons in the presence of quasi-hole excitations are explicitly given for\nm=2.", "Since its launch in 1999, the Far Ultraviolet Spectroscopic Explorer (FUSE)\nhas made over 4600 observations of some 2500 individual targets. The data are\nreduced by the Principal Investigator team at the Johns Hopkins University and\narchived at the Multimission Archive at Space Telescope (MAST). The\ndata-reduction software package, called CalFUSE, has evolved considerably over\nthe lifetime of the mission. The entire FUSE data set has recently been\nreprocessed with CalFUSE v3.2, the latest version of this software. This paper\ndescribes CalFUSE v3.2, the instrument calibrations upon which it is based, and\nthe format of the resulting calibrated data files.", "S255N is a luminous far-infrared source that contains many indications of\nactive star formation but lacks a prominent near-infrared stellar cluster. We\npresent mid-infrared through radio observations aimed at exploring the\nevolutionary state of this region. Our observations include 1.3mm continuum and\nspectral line data from the Submillimeter Array, VLA 3.6cm continuum and 1.3cm\nwater maser data, and multicolor IRAC images from the Spitzer Space Telescope.\nThe cometary morphology of the previously-known UCHII region G192.584-0.041 is\nclearly revealed in our sensitive, multi-configuration 3.6cm images. The 1.3mm\ncontinuum emission has been resolved into three compact cores, all of which are\ndominated by dust emission and have radii < 7000AU. The mass estimates for\nthese cores range from 6 to 35 Msun. The centroid of the brightest dust core\n(SMA1) is offset by 1.1'' (2800 AU) from the peak of the cometary UCHII region\nand exhibits the strongest HC3N, CN, and DCN line emission in the region. SMA1\nalso exhibits compact CH3OH, SiO, and H2CO emission and likely contains a young\nhot core. We find spatial and kinematic evidence that SMA1 may contain further\nmultiplicity, with one of the components coincident with a newly-detected H2O\nmaser. There are no mid-infrared point source counterparts to any of the dust\ncores, further suggesting an early evolutionary phase for these objects. The\ndominant mid-infrared emission is a diffuse, broadband component that traces\nthe surface of the cometary UCHII region but is obscured by foreground material\non its southern edge. An additional 4.5 micron linear feature emanating to the\nnortheast of SMA1 is aligned with a cluster of methanol masers and likely\ntraces a outflow from a protostar within SMA1. Our observations provide direct\nevidence that S255N is forming a cluster of intermediate to high-mass stars.", "We discuss ways in which the ratio of exchange constants along the rungs and\nlegs of a spin-ladder material influences the two-magnon Raman scattering\nspectra and hence can be determined from it. We show that within the\nFleury-Loudon-Elliott approach, the Raman line-shape does not change with\npolarization geometries. This lineshape is well known to be difficult to\ncalculate accurately from theory. However, the Raman scattering intensities do\nvary with polarization geometries, which are easy to calculate. With some\nassumptions about the Raman scattering Hamiltonian, the latter can be used to\nestimate the ratio of exchange constants. We apply these results to Sugai's\nrecent measurements of Raman scattering from spin-ladder materials such as\nLa$_6$Ca$_8$Cu$_{24}$O$_{41}$ and Sr$_{14}$Cu$_{24}$O$_{41}$.", "Statistical properties of billiards with diffusive boundary scattering are\ninvestigated by means of the supersymmetric sigma-model in a formulation\nappropriate for chaotic ballistic systems. We study level statistics,\nparametric level statistics, and properties of electron wavefunctions. In the\nuniversal regime, our results reproduce conclusions of the random matrix\ntheory, while beyond this regime we obtain a variety of system-specific results\ndetermined by the classical dynamics in the billiard. Most notably, we find\nthat level correlations do not vanish at arbitrary separation between energy\nlevels, or if measured at arbitrarily large difference of magnetic fields.\nSaturation of the level number variance indicates strong rigidity of the\nspectrum. To study spatial correlations of wavefunction amplitudes, we\nreanalyze and refine derivation of the ballistic version of the sigma-model.\nThis allows us to obtain a proper matching of universal short-scale\ncorrelations with system-specific ones.", "In their recent paper, Campana et al. (2007) found that 5 bursts, among those\ndetected by Swift, are outliers with respect to the E_peak-E_gamma\n(\"Ghirlanda\") correlation. We instead argue that they are not.", "We use large cosmological N-body simulations to study the subhalo population\nin galaxy group sized halos. In particular, we look for fossil group candidates\nwith typical masses ~10-25% of Virgo cluster but with an order of magnitude\nless substructure. We examine recent claims that the earliest systems to form\nare deficient enough in substructure to explain the luminosity function found\nin fossil groups. Although our simulations show a correlation between the halo\nformation time and the number of subhalos, the maximum suppression of subhalos\nis a factor of 2-2.5, whereas a factor of 6 is required to match fossil groups\nand galaxies. While the number of subhalos depends weakly on the formation\ntime, the slope of the halo substructure velocity function does not. The\nsatellite population within Cold Dark Matter (CDM) halos is self-similar at\nscales between galaxies and galaxy clusters regardless of mass, whereas current\nobservations show a break in self-similarity at a mass scale corresponding to\ngroup of galaxies.", "About 25% of the Milky Way globular clusters (GCs) exhibit unusually extended\ncolor distribution of stars in the horizontal-branch (HB) phase. This\nphenomenon is now best understood as due to the presence of helium enhanced\nsecond generation subpopulations, which has raised a possibility that these\npeculiar GCs might have a unique origin. Here we show that these GCs with\nextended HB are clearly distinct from other normal GCs in kinematics and mass.\nThe GCs with extended HB are more massive than normal GCs, and are dominated by\nrandom motion with no correlation between kinematics and metallicity.\nSurprisingly, however, when they are excluded, most normal GCs in the inner\nhalo show clear signs of dissipational collapse that apparently led to the\nformation of the disk. Normal GCs in the outer halo share their kinematic\nproperties with the extended HB GCs, which is consistent with the accretion\norigin. Our result further suggests heterogeneous origins of GCs, and we\nanticipate this to be a starting point for more detailed investigations of\nMilky Way formation, including early mergers, collapse, and later accretion.", "We present high resolution imaging of the puzzling radio and optical nebula\nG70.7+1.2 with the Keck Observatory's laser guide star adaptive optics (LGS-AO)\nsystem and the Chandra X-ray Observatory. The archival X-ray observations show\na hard (Gamma ~ 1.8), low luminosity (L_X ~ 4 x 10^31 ergs/s) point source at\nthe center of the nebula. Follow-up LGS-AO near-infrared imaging of the Chandra\nerror circle reveals a relatively bright (K' ~ 14 magnitude) counterpart. Both\nits color and brightness are consistent with a heavily obscured B-star or\npossibly a late-G/early-K giant. The most plausible explanation is that this\nnewly discovered X-ray source is a non-accreting B-star/pulsar binary powering\nthe radio and optical nebula. If so, the luminous Be-star discussed in the\nliterature seemingly embedded in the nebula is not the dominant force\nresponsible for shaping G70.7+1.2. Thus, we suggest that G70.7+1.2 is the\nresult of two unrelated objects (a B-star X-ray binary and a Be star)\ninteracting with a dense molecular cloud. With this explanation we believe we\nhave solved the mystery of the origin of G70.7+1.2.", "Bose-Einstein condensates of $^7$Li have been limited in number due to\nattractive interatomic interactions. Beyond this number, the condensate\nundergoes collective collapse. We study theoretically the effect of driving\nlow-lying collective modes of the condensate by a weak asymmetric sinusoidally\ntime-dependent field. We find that driving the radial breathing mode further\ndestabilizes the condensate, while excitation of the quadrupolar surface mode\ncauses the condensate to become more stable by imparting quasi-angular momentum\nto it. We show that a significantly larger number of atoms may occupy the\ncondensate, which can then be sustained almost indefinitely. All effects are\npredicted to be clearly visible in experiments and efforts are under way for\ntheir experimental realization.", "We analyze the optically induced Kondo effect in the absorption spectrum for\na quantum dot with an even number of electrons, for which the Kondo effect does\nnot occur in the ground state. The Kondo exchange couplings generated for\nphoto-excited states can be either antiferromagnetic or ferromagnetic, which\nmay result in different types of the edge singularities, depending on the\nmicroscopic parameters of the dot. We discuss critical properties in the\nspectrum by using low-energy effective field theory.", "We show that a scattering rate which varies with angle around the Fermi\nsurface has the same effect as a periodic Lorentz force on magnetotransport\ncoefficients. This effect, together with the marginal Fermi liquid inelastic\nscattering rate gives a quantitative explanation of the temperature dependence\nand the magnitude of the observed Hall effect and magnetoresistance with just\nthe measured zero-field resistivity as input.", "We argue that the discrepancies observed in HII regions between abundances\nderived from optical recombination lines (ORLs) and collisionally excited lines\n(CELs) might well be the signature of a scenario of the enrichment of the\ninterstellar medium (ISM) proposed by Tenorio-Tagle (1996). In this scenario,\nthe fresh oxygen released during massive supernova explosions is confined\nwithin the hot superbubbles as long as supernovae continue to explode. Only\nafter the last massive supernova explosion, the metal-rich gas starts cooling\ndown and falls on the galaxy within metal-rich droplets. Full mixing of these\nmetal-rich droplets and the ISM occurs during photoionization by the next\ngenerations of massive stars. During this process, the metal-rich droplets give\nrise to strong recombination lines of the metals, leading to the observed\nORL-CEL discrepancy. (The full version of this work is submitted to Astronomy\nand Astrophysics.)", "A few FRI radio galaxies were detected at GeV gamma-rays with CGRO EGRET,\nwith peroperties suggesting that the gamma-ray flux originates from the core.\nHere we discuss the possibility that the extended radio features of radio\ngalaxies could be detected with the LAT, focusing on the particularly promising\ncase of the nearby giant radio galaxy Fornax A.", "We present results of the analysis of cometary X-ray spectra with an extended\nversion of our charge exchange emission model (Bodewits et al. 2006). We have\napplied this model to the sample of 8 comets thus far observed with the Chandra\nX-ray observatory and ACIS spectrometer in the 300-1000 eV range. The surveyed\ncomets are C/1999 S4 (LINEAR), C/1999 T1 (McNaught-Hartley), C/2000 WM1\n(LINEAR), 153P/2002 (Ikeya-Zhang), 2P/2003 (Encke), C/2001 Q4 (NEAT), 9P/2005\n(Tempel 1) and 73P/2006-B (Schwassmann-Wachmann 3) and the observations include\na broad variety of comets, solar wind environments and observational\nconditions. The interaction model is based on state selective, velocity\ndependent charge exchange cross sections and is used to explore how cometary\nX-ray emission depend on cometary, observational and solar wind\ncharacteristics. It is further demonstrated that cometary X-ray spectra mainly\nreflect the state of the local solar wind. The current sample of Chandra\nobservations was fit using the constrains of the charge exchange model, and\nrelative solar wind abundances were derived from the X-ray spectra. Our\nanalysis showed that spectral differences can be ascribed to different solar\nwind states, as such identifying comets interacting with (I) fast, cold wind,\n(II), slow, warm wind and (III) disturbed, fast, hot winds associated with\ninterplanetary coronal mass ejections. We furthermore predict the existence of\na fourth spectral class, associated with the cool, fast high latitude wind.", "Cold dark matter haloes are populated by caustics, which are yet to be\nresolved in N-body simulations or observed in the Universe. Secondary infall\nmodel provides a paradigm for the study of caustics in \"typical\" haloes\nassuming that they have had no major mergers and have grown only by smooth\naccretion. This is a particular characteristic of the smallest dark matter\nhaloes of about 10^{-5} Mo, which although \"atypical\" contain no substructures\nand could have survived until now with no major mergers. Thus using this model\nas the first guidline, we evaluate the neutralino self-annihilation flux for\nthese haloes. Our results show that caustics could leave a distinct sawteeth\nsignature on the differential and cumulative fluxes coming from the outer\nregions of these haloes. The total annihilation signal from the regions away\nfrom the centre can be boosted by about forty percents.", "In two dimensions the microscopic theory, which provides a basis for the\nnaive analogy between a quantized vortex in a superfluid and an electron in an\nuniform magnetic field, is presented. A one-to-one correspondence between the\nrotational states of a vortex in a cylinder and the cyclotron states of an\nelectron in the central gauge is found. Like the Landau levels of an electron,\nthe energy levels of a vortex are highly degenerate. However, the gap between\ntwo adjacent energy levels does not only depend on the quantized circulation,\nbut also increases with the energy, and scales with the size of the vortex.", "We have created spatial dark solitons in two-component Bose-Einstein\ncondensates in which the soliton exists in one of the condensate components and\nthe soliton nodal plane is filled with the second component. The filled\nsolitons are stable for hundreds of milliseconds. The filling can be\nselectively removed, making the soliton more susceptible to dynamical\ninstabilities. For a condensate in a spherically symmetric potential, these\ninstabilities cause the dark soliton to decay into stable vortex rings. We have\nimaged the resulting vortex rings.", "We consider the damping of condensate collective modes at finite temperatures\narising from lack of equilibrium between the condensate and the non-condensate\natoms, an effect that is ignored in the usual discussion of the collisionless\nregion. As a first approximation, we ignore the dynamics of the thermal cloud.\nOur calculations should be applicable to collective modes of the condensate\nwhich are oscillating out-of-phase with the thermal cloud. We obtain a\ngeneralized Stringari equation of motion for the condensate at finite\ntemperatures, which includes a damping term associated with the fact that the\ncondensate is not in diffusive equilibrium with the static thermal cloud. This\ninter-component collisional damping of the condensate modes is comparable in\nmagnitude to the Landau damping considered in the recent literature.", "We present the results of a visible spectroscopic and photometric survey of\nJupiter Trojans belonging to different dynamical families carried out at the\nESO-NTT telescope. We obtained data on 47 objects, 23 belonging to the L5 swarm\nand 24 to the L4 one. These data together with those already published by\nFornasier et al. (2004a) and Dotto et al. (2006), constitute a total sample of\nvisible spectra for 80 objects. The survey allows us to investigate six\nfamilies (Aneas, Anchises, Misenus, Phereclos, Sarpedon, Panthoos) in the L5\ncloud and four L4 families (Eurybates, Menelaus, 1986 WD and 1986 TS6). The\nsample that we measured is dominated by D--type asteroids, with the exception\nof the Eurybates family in the L4 swarm, where there is a dominance of C- and\nP-type asteroids. All the spectra that we obtained are featureless with the\nexception of some Eurybates members, where a drop--off of the reflectance is\ndetected shortward of 5200 A. Similar features are seen in main belt C-type\nasteroids and commonly attributed to the intervalence charge transfer\ntransition in oxidized iron. Our sample comprises fainter and smaller Trojans\nas compared to the literature's data and allows us to investigate the\nproperties of objects with estimated diameter smaller than 40--50 km. The\nanalysis of the spectral slopes and colors versus the estimated diameters shows\nthat the blue and red objects have indistinguishable size distribution. We\nperform a statistical investigation of the Trojans's spectra property\ndistributions as a function of their orbital and physical parameters, and in\ncomparison with other classes of minor bodies in the outer Solar System.\nTrojans at lower inclination appear significantly bluer than those at higher\ninclination, but this effect is strongly driven by the Eurybates family.", "We conduct a systematic examination of the properties of models for\nchemically homogeneous, differentially rotating, main-sequence stars of mass\n1-2 M_sun. The models were constructed using a code based on a reformulation of\nthe self-consistent field method of computing the equilibrium stellar structure\nfor a specified conservative internal rotation law. [abridged] Relative to\nnonrotating stars of the same mass, these models all have reduced luminosities\nand effective temperatures, and flattened photospheric shapes (i.e., decreased\npolar radii) with equatorial radii that can be larger or smaller, depending on\nthe degree of differential rotation. For a fixed ratio of the axial rotation\nrate to the surface equatorial rotation rate, increasingly rapid rotation\ngenerally deepens convective envelopes, shrinks convective cores, and can lead\nto the presence of a convective core (envelope) in a 1 M_sun (2 M_sun) model, a\nfeature that is absent in a nonrotating star of the same mass. The positions of\ndifferentially rotating models for a given mass M in the H-R diagram can be\nshifted in such a way as to approximate the nonrotating ZAMS over ranges in\nluminosity and effective temperature that correspond to a mass interval between\nM and about 0.7 M. We briefly note a few of the implications of these results,\nincluding (i) possible ambiguities arising from similarities between the\nproperties of rotating and nonrotating models of different masses, (ii) a\nreduced radiative luminosity for a young, rapidly rotating Sun, (iii) the\nnuclear destruction of lithium and other light metallic species in the layers\nbeneath an outer convective envelope, and (iv), the excitation of solar-like\noscillations and the operation of a solar-like hydromagnetic dynamo in some\n1.5-2 M_sun stars.", "This chapter summarizes analytic theory and numerical calculations for the\nformation and collisional evolution of KBOs at 20--150 AU. We describe the main\npredictions of a baseline self-stirring model and show how dynamical\nperturbations from a stellar flyby or stirring by a giant planet modify the\nevolution. Although robust comparisons between observations and theory require\nbetter KBO statistics and more comprehensive calculations, the data are broadly\nconsistent with KBO formation in a massive disk followed by substantial\ncollisional grinding and dynamical ejection. However, there are important\nproblems reconciling the results of coagulation and dynamical calculations.\nContrasting our current understanding of the evolution of KBOs and asteroids\nsuggests that additional observational constraints, such as the identification\nof more dynamical families of KBOs (like the 2003 EL61 family), would provide\nadditional information on the relative roles of collisional grinding and\ndynamical ejection in the Kuiper Belt. The uncertainties also motivate\ncalculations that combine collisional and dynamical evolution, a `unified'\ncalculation that should give us a better picture of KBO formation and\nevolution.", "The spin-split Fermi level crossings of the conduction band in Ni are mapped\nout by high-resolution photoemission and compared to the equivalent crossing in\nCu. The area of the quasiparticle peak decreases rapidly below Ef in Ni, but\nnot in Cu. Majority spins have larger spectral weight at Ef than minority\nspins, thereby enhancing the spin-polarization beyond that expected from the\ndensity of states. A large part of the effect can be traced to a rapid\nvariation of the matrix element with {\\bf k} at the point where the s,p-band\nbegins to hybridize with the $dz^2$ state. However, it is quite possible that\nthe intensity drop in Ni is reinforced by a transfer of spectral weight from\nsingle-particle to many-electron excitations. The results suggest that the\nmatrix element should be considered for explaining the enhanced spin\npolarization observed for Ni in spin-polarized tunneling.", "Ground state of the two-dimensional hard-core-boson model subjected to\nexternal magnetic field and quenched random chemical potential is studied\nnumerically. In experiments, magnetic-field-tuned superconductor-insulator\ntransition has already come under through investigation, whereas in computer\nsimulation, only randomness-driven localization (with zero magnetic field) has\nbeen studied so far: The external magnetic field brings about a difficulty that\nthe hopping amplitude becomes complex number (through the gauge twist), for\nwhich the quantum Monte-Carlo simulation fails. Here, we employ the exact\ndiagonalization method, with which we demonstrate that the model does exhibit\nfield-tuned localization transition at a certain critical magnetic field. At\nthe critical point, we found that the DC conductivity is not universal, but is\nsubstantially larger than that of the randomness-driven localization transition\nat zero magnetic field. Our result supports recent experiment by Markovi'c et\nal. reporting an increase of the critical conductivity with magnetic field\nstrengthened.", "For dynamical dark energy cosmologies we carry out a series of N-body\ngravitational simulations, achieving percent level accuracy in the relative\nmass power spectra at any redshift. Such accuracy in the power spectrum is\nnecessary for next generation cosmological mass probes. Our matching procedure\nreproduces the CMB distance to last scattering and delivers subpercent level\npower spectra at z=0 and z~3. We discuss the physical implications for probing\ndark energy with surveys of large scale structure.", "We have derived orbital basis sets from scattering theory. They are expressed\nas polynomial approximations to the energy dependence of a set of partial\nwaves, in quantized form. The corresponding matrices, as well as the\nHamiltonian and overlap matrices, are specified by the values on the energy\nmesh of the screened resolvent and its first energy derivative. These orbitals\nare a generalization of the 3rd-generation linear MTOs and should be useful for\nelectronic-structure calculations in general.", "We study the properties of a simple lattice model of repulsive particles\ndiffusing in a pinning landscape. The behaviour of the model is very similar to\nthe observed physics of vortices in superconductors. We compare and discuss the\nequilibrium phase diagram, creep dynamics, the Bean state profiles, hysteresis\nof magnetisation loops (including the second peak feature), and, in particular,\n``off equilibrium'' relaxations. The model is analytically tractable in replica\nmean field theory and numerically via Monte Carlo simulations. It offers a\ncomprehensive schematic framework of the observed phenomenology.", "We derive correlation coefficients between temperature and line-of-sight\nvelocity as a function of optical depth throughout the solar photosphere for\nthe non-magnetic photosphere and a small area of enhanced magnetic activity.\nThe maximum anticorrelation of about -0.6 between temperature and line-of-sight\nvelocity in the non-magnetic photosphere occurs at log tau5 = -0.4. The\nmagnetic field is another decorrelating factor along with 5-min oscillations\nand seeing.", "X-ray surveys facilitate investigations of the environment of AGNs. Deep\nChandra observations revealed that the AGNs source surface density rises near\nclusters of galaxies. The natural extension of these works is the measurement\nof spatial clustering of AGNs around clusters and the investigation of relative\nbiasing between active galactic nuclei and galaxies near clusters.The major\naims of this work are to obtain a measurement of the correlation length of AGNs\naround clusters and a measure of the averaged clustering properties of a\ncomplete sample of AGNs in dense environments. We present the first measurement\nof the soft X-ray cluster-AGN cross-correlation function in redshift space\nusing the data of the ROSAT-NEP survey. The survey covers 9x9 deg^2 around the\nNorth Ecliptic Pole where 442 X-ray sources were detected and almost completely\nspectroscopically identified. We detected a >3sigma significant clustering\nsignal on scales s<50 h70^-1 Mpc. We performed a classical maximum-likelihood\npower-law fit to the data and obtained a correlation length s_0=8.7+1.2-0.3\nh_70-1 Mpc and a slope gamma=1.7$^+0.2_-0.7 (1sigma errors). This is a strong\nevidence that AGNs are good tracers of the large scale structure of the\nUniverse. Our data were compared to the results obtained by cross-correlating\nX-ray clusters and galaxies. We observe, with a large uncertainty, that the\nbias factor of AGN is similar to that of galaxies.", "A stack of tensionless membranes with nonlinear curvature energy and vertical\nharmonic interaction is studied. At low temperatures, the system forms a\nlamellar phase. At a critical temperature, the stack disorders vertically in a\nmelting-like transition.", "We calculate exactly the density of magnon states of the regularly\nalternating spin-1/2 XX chain with Dzyaloshinskii-Moriya interaction. The\nobtained results permit us to examine the stability of the chain with respect\nto spin-Peierls dimerization. We found that depending on the dependences of\nDzyaloshinskii-Moriya interaction on distortion amplitude it may act either in\nfavour of the dimerization or against the dimerization.", "The recently realized multicomponent Bose-Einstein condensates provide\nopportunities to explore the rich physics brought about by the spin degrees of\nfreedom. For instance, we can study spin waves and phase separation,\nmacroscopic quantum tunneling, Rabi oscillations, the coupling between spin\ngradients and superfluid flow, squeezed spin states, vortices and other\ntopological excitations. Theoretically, there have been already some studies of\nthe ground-state properties of these systems and their line-like vortex\nexcitations. In analogy with nuclear physics or the quantum Hall effect, we\nexplore here the possibility of observing point-like topological excitations or\nskyrmions. These are nontrivial spin textures that in principle can exist in a\nspinor Bose-Einstein condensate. In particular, we investigate the stability of\nskyrmions in a fictitious spin-1/2 condensate of Rb87 atoms. We find that\nskyrmions can exist in this case only as a metastable state, but with a\nlifetime of the order of, or even longer than, the typical lifetime of the\ncondensate itself. In addition to determining the size and the lifetime of the\nskyrmion, we also present its spin texture and finally briefly consider its\ndynamical properties.", "We have investigated the far-infrared dipole modes of a quantum antidot\nsubmitted to a perpendicularly applied magnetic field B. The ground state of\nthe antidot is described within local spin-density functional theory, and the\nspectrum within time-dependent local spin-density functional theory. The\nresults are compared with those corresponding to a quantum dot of similar\nelectronic surface density. The method is able to reproduce two of the more\nsalient experimental features, namely that main bulk and edge modes have the\nsame circular polarization, and that the negative B dispersion edge branch\noscillates, having minima at the B values corresponding to fully occupied\nLandau levels. It fails, however, to yield the unique feature of short-period\nantidot lattices that the energy of the edge magnetoplasmon approaches the\ncyclotron frequency for small B. The existence of anticyclotron polarized bulk\nmodes is discussed, and a detailed account of the dipole spin mode is\npresented.", "This paper has been withdrawn by the authors due to several major changes in\nconcepts and results. New version will follow briefly as a new e-print.", "We look for wide, faint companions around members of the 5 Myr Lambda Orionis\nopen cluster. We used optical, near-infrared, and Spitzer/IRAC photometry. We\nreport the discovery of a very wide very low mass visual binary, LOri167,\nformed by a brown dwarf and a planetary-mass candidate located at 5 arcsec,\nwhich seems to belong to the cluster. We derive Teff of 2125 and 1750 K. If\nthey are members, comparisons with theoretical models indicate masses of 17\n(20-15) Mjup and 8 (13-7) Mjup, with a projected separation of 2000 AU. Such a\nbinary system would be difficult to explain in most models, particularly those\nwhere substellar objects form in the disks surrounding higher mass stars.", "We analyze theoretically the dynamics of aeolian sand ripples. In order to\nput the study in the context we first review existing models. We argue on the\nlocal character of sand ripple formation. Using a hydrodynamical model we\nderive a nonlinear equation for the sand profile. We show how the\nhydrodynamical model may be modified to recover the missing terms that are\ndictated by symmetries. The symmetry and conservation arguments are powerful in\nthat the form of the equation is model-independent. We then present an\nextensive numerical and analytical analysis of the generic sand ripple\nequation. We find that at the initial stage the wavelength of the ripple is\nthat corresponding to the linearly most dangerous mode. At later stages the\nprofile undergoes a coarsening process leading to a significant increase of the\nwavelength. We find that including the next higher order nonlinear term in the\nequation, leads naturally to a saturation of the local slope. We analyze both\nanalytically and numerically the coarsening stage, in terms of a dynamical\nexponent for the mean wavelength increase. We discuss some future lines of\ninvestigations.", "One of the most surprising discoveries of extrasolar planets is the detection\nof planets in moderately close binary star systems. The Jovian-type planets in\nthe two binaries of Gamma Cephei and GJ 86 have brought to the forefront\nquestions on the formation of giant planets and the possibility of the\nexistence of smaller bodies in such dynamically complex environments. The\ndiverse dynamical characteristics of these objects have made scientists wonder\nto what extent the current theories of planet formation can be applied to\nbinaries and multiple star systems. At present, the sensitivity of the\ndetection techniques does not allow routine discovery of Earth-sized bodies in\nbinary systems. However, with the advancement of new techniques, and with the\nrecent launch of CoRoT and the launch of Kepler in late 2008, the detection of\nmore planets (possibly terrestrial-class objects) in such systems is on the\nhorizon. Theoretical studies and numerical modeling of terrestrial and\nhabitable planet formation are, therefore, necessary to gain fundamental\ninsights into the prospects for life in such systems and have great strategic\nimpact on NASA science and missions.", "We consider the dependence magnetization vs. field at zero temperature for\nthe spin-1/2 chains in which the intersite interactions regularly vary from\nsite to site with a period p. In the limiting case when the smallest value of\nthe intersite interactions tends to zero the chain splits into noninteracting\nidentical fragments of p sites and the dependence magnetization vs. field can\nbe examined rigorously. We demonstrate explicitly the appearance of plateaus in\nsuch dependence and discuss a presence of the magnetization values m predicted\nby the condition p(1/2-m)=integer [1]. We comment on the influence of the\nanisotropy in the interspin interaction on the magnetization profiles. Finally,\nwe show how the case of nonzero smallest value of the intersite interactions\ncan be considered.", "We search for and characterize substructures in the projected distribution of\ngalaxies observed in the wide field CCD images of the 77 nearby clusters of the\nWIde-field Nearby Galaxy-cluster Survey (WINGS). This sample is complete in\nX-ray flux in the redshift range 0.04<z<0.07. We search for substructures in\nWINGS clusters with DEDICA, an adaptive-kernel procedure. We test the procedure\non Monte-Carlo simulations of the observed frames and determine the reliability\nfor the detected structures. DEDICA identifies at least one reliable structure\nin the field of 55 clusters. 40 of these clusters have a total of 69\nsubstructures at the same redshift of the cluster (redshift estimates of\nsubstructures are from color-magnitude diagrams). The fraction of clusters with\nsubclusters (73%) is higher than in most studies. The presence of subclusters\naffects the relative luminosities of the brightest cluster galaxies (BCGs).\nDown to L ~ 10^11.2 L_Sun, our observed differential distribution of subcluster\nluminosities is consistent with the theoretical prediction of the differential\nmass function of substructures in cosmological simulations.", "We calculate stable arrangements for a single superfluid vortex pinned to the\nwall of a stationary cylindrical container. We find that, independent of the\ndetails of the pinning site, stable vortices must subtend most of the cell\nhorizontally and cannot be vertical or nearly vertical. More generally, the\ngeometry of a container severely limits the possible vortex configurations,\nmaking macroscopic trapped vortices less common than previously believed.", "The dependence on the temperature of photospheric line-depth ratios (LDRs) in\nthe spectral range 6190-6280 A is investigated by using a sample of 174 ELODIE\nArchive stellar spectra of luminosity class from V to III. The rotational\nbroadening effect on LDRs is also studied. We provide useful calibrations of\neffective temperature versus LDRs for giant and main sequence stars with\n3800<Teff<6000 K and vsini in the range 0-30 km/s. We found that, with the\nexception of very few line pairs, LDRs, measured at a spectral resolution as\nhigh as 42000, depend on vsini and that, by neglecting the rotational\nbroadening effect, one can mistake the Teff determination of 100 K in the worst\ncases.", "We consider the effect of a small cut-off epsilon on the velocity of a\ntraveling wave in one dimension. Simulations done over more than ten orders of\nmagnitude as well as a simple theoretical argument indicate that the effect of\nthe cut-off epsilon is to select a single velocity which converges when epsilon\ntends to 0 to the one predicted by the marginal stability argument. For small\nepsilon, the shift in velocity has the form K(log epsilon)^(-2) and our\nprediction for the constant K agrees very well with the results of our\nsimulations. A very similar logarithmic shift appears in more complicated\nsituations, in particular in finite size effects of some microscopic stochastic\nsystems. Our theoretical approach can also be extended to give a simple way of\nderiving the shift in position due to initial conditions in the\nFisher-Kolmogorov or similar equations.", "We review the present state of theory and experiments on the quantum\ntunneling of magnetization in mesoscopic spin systems. Most attention is paid\nto the relaxation of magnetization in the molecular complexes Mn12 and Fe8. The\nrole of the thermostat (phonons, nuclear spins, dipolar fields) is studied.", "We present a new catalog of star cluster candidates in the nearby spiral\ngalaxy M33. It is based on eight existing catalogs wherein we have\ncross-referenced identifications and endeavored to resolve inconsistencies\nbetween them. Our catalog contains 451 candidates of which 255 are confirmed\nclusters based on HST and high resolution ground-based imaging. The catalog\ncontains precise cluster positions (RA and Dec), magnitudes and colors in the\nUBVRIJHKs filters, metallicities, radial velocities, masses and ages, where\navailable, and galactocentric distances for each cluster. The color\ndistribution of the M33 clusters appears to be similar to those in the Large\nMagellanic Cloud with major peaks at (B-V)o~0.15, and (B-V)o~0.65. The\nintrinsic colors are correlated with cluster ages, which range from 10^{7.5} to\n10^{10.3} years. The age distribution of the star clusters supports the notion\nof rapid cluster disruption with a slope of alpha=-1.09 +/- 0.07 in the\ndN_{cluster}/dt ~ t^{alpha} relation. In addition, comparison to theoretical\nsingle stellar population models suggests the presence of an age-metallicity\nrelation among these clusters with younger clusters being more metal-rich.\nAnalysis of the radial distribution of the clusters yields some evidence that\nyounger clusters (age <~ 1 Gyr) may be more concentrated toward the center of\nM33 than older ones. A similar comparison with the radial profile of the M33\nfield stars shows the clusters to be more centrally concentrated at the greater\nthan 99.9% confidence level. Possible reasons for this are presented and\ndiscussed; however, the overwhelming conclusion seems to be that a more\ncomplete and thorough cluster search is needed covering at least 4 square\ndegrees centered on M33.", "We present new Faraday rotation measures (RMs) for 148 extragalactic radio\nsources behind the southern Galactic plane (253o < l < 356o, |b| < 1.5o), and\nuse these data in combination with published data to probe the large-scale\nstructure of the Milky Way's magnetic field. We show that the magnitudes of\nthese RMs oscillate with longitude in a manner that correlates with the\nlocations of the Galactic spiral arms. The observed pattern in RMs requries the\npresence of at least one large-scale magnetic reversal in the fourth Galactic\nquadrant, located between the Sagittarius- Carina and Scutum-Crux spiral arms.\nTo quantitatively compare our measurements to other recent studies, we consider\nall available extragalactic and pulsar RMs in the region we have surveyed, and\njointly fit these data to simple models in which the large-scale field follows\nthe spiral arms. In the best-fitting model, the magnetic field in the fourth\nGalactic quadrant is directed clockwise in the Sagittarius-Carina spiral arm\n(as viewed from the North Galactic pole), but is oriented counter- clockwise in\nthe Scutum-Crux arm. This contrasts with recent analyses of pulsar RMs alone,\nin which the fourth-quadrant field was presumed to be directed\ncounter-clockwise in the Sagittarius- Carina arm. Also in contrast to recent\npulsar RM studies, our joint modeling of pulsar and extragalactic RMs\ndemonstrates that large numbers of large-scale magnetic field reversals are not\nrequired to account for observations.", "We consider a model of N two-dimensional bosons in a harmonic trap with\ntranslational and rotational invariant, weak two-particle interaction. We\npresent in configuration space a systematical recursive method for constructing\nall wave functions with angular momentum L and corresponding energies and apply\nit to L\\leq 6 for all N. The lower and the upper bounds for interaction energy\nare estimated. We analitically confirm the conjecture of Smith et al. that\nelementary symmetric polynomial is the ground state for repulsive delta\ninteraction, for all N\\geq L up to L\\leq 6. Additionally, we find that there\nexist vanishing-energy solutions for L\\geq N(N-1), signalizing the exclusive\nstatistics. Finally, we consider briefly the case of attractive power-like\npotential r^k, k>-2, and prove that the lowest-energy state is still the one in\nwhich all angular momentum is absorbed by the center-of-mass motion.", "We consider a two-dimensional dilute Bose gas above its superfluid transition\ntemperature. We show that the t-matrix approximation corresponds to the leading\nset of diagrams in the dilute limit, provided the temperature is sufficiently\nlarger than the superfluid transition temperature. Within this approximation,\nwe give an explicit expression for the wave vector and frequency dependence of\nthe self-energy, and calculate the corrections to the chemical potential and\nthe effective mass arising from the interaction. We also argue that the\nbreakdown of the t-matrix approximation, which occurs upon lowering the\ntemperature, provides a simple criterion to estimate the superfluid critical\ntemperature for the two-dimensional dilute Bose gas. The critical temperature\nidentified by this criterion coincides with earlier results obtained by Popov\nand by Fisher and Hohenberg using different methods. Extension of this\nprocedure to the three-dimensional case gives good agreement with recent Monte\nCarlo data.", "The exact solution for a system with two-particle annihilation and\ndecoagulation has been studied. The spectrum of the Hamiltonian of the system\nis found. It is shown that the steady state is two-fold degenerate. The average\nnumber density in each cite <n_i(t)> and the equal time two-point functions\n<n_i(t), n_j(t)> are calculated. Any equal time correlation functions at large\ntimes,\n  $<n_i({\\infty}), n_j({\\infty}), ...>$, is also calculated. The relaxation\nbehaviour of the system toward its final state is investigated and it is shown\nthat generally it is exponential, as it is expected. For the special symmetric\ncase, the relaxation behaviour of the system is a power law. For the asymmetric\ncase, it is shown that the profile of deviation from the final values is an\nexponential function of the position.", "We exploit the analogy with the Quantum Hall (QH) system to study weakly\ninteracting bosons in a harmonic trap. For a $\\delta$-function interaction\npotential the ``yrast'' states with $L\\ge N(N-1)$ are degenerate, and we show\nhow this can be understood in terms of Haldane exclusion statistics. We present\nspectra for 4 and 8 particles obtained by numerical and algebraic methods, and\ndemonstrate how a more general hard-core potential lifts the degeneracies on\nthe yrast line. The exact wavefunctions for N=4 are compared with trial states\nconstructed from composite fermions (CF), and the possibility of using\nCF-states to study the low L region at high N is discussed.", "A ToO observation of the TeV-emitting blazar Mrk 421 with INTEGRAL was\ntriggered in June 2006 by an increase of the RXTE count rate to more than 30\nmCrab. The source was then observed with all INTEGRAL instruments with the\nexception of the spectrometer SPI for a total exposure of 829 ks. During this\ntime several outbursts were observed by IBIS and JEM-X. Multiwavelength\nobservations were immediately triggered and the source was observed at radio,\noptical and X-ray wavelengths up to TeV energies. The data obtained during\nthese observations are analysed with respect to spectral evolution and\ncorrelated variability. Preliminary results of the analysis are presented in\nthis poster.", "The space velocities from the catalog of Nordstrom et al. (2004) are used to\ntrace variations of a number of kinematic parameters of single F and G dwarfs\nas a function of their age. The vertex deviation of disk stars increases from\n7+- 1 to 15+-2 degrees as the mean age decreases from 4.3 to 1.5 Gyr. The\ntwo-dimensional velocity distributions in the UV, UW, and VW planes are\nanalyzed. The evolution of the main peaks in the velocity distributions can be\nfollowed to an average age of approximately 9 Gyr. We find that: (1) in the\ndistributions of the UV velocity components, stars of different types are\nconcentrated toward several stable peaks (the Hyades, Pleiades, and Sirius\nCluster), suggesting that the stars belonging to these formations did not form\nsimultaneously; (2) the peak associated with the Hyades Cluster dominates in\nall age intervals; and (3) the Hyades peak is strongest for stars with an\naverage age of 1.5 Gyr, suggesting that this peak contains a considerable\nfraction of stars from the Hyades cluster. The age dependences of the kinematic\nparameters exhibit a break near 4.5 Gyr, which can be explained as an effect of\nthe different contributions of stars of the thin and thick disks. The Stromberg\nrelation yields a solar LSR velocity of V_{\\odot LSR} = (8.7, 6.2, 7.2)+- (0.5,\n2.2, 0.8) km/s.", "A dynamical price formation model for financial assets is presented. It aims\nto capture the essence of speculative trading where mispricings of assets are\nused to make profits. It is shown that together with the incorporation of the\nconcept of risk aversion of agents the model is able to reproduce several key\ncharacteristics of financial price series. The approach is contrasted to the\nconventional view of price formation in financial economics.", "We present maps of 1.5 square degrees of the Serpens dark cloud at 24, 70,\nand 160\\micron observed with the Spitzer Space Telescope MIPS Camera. More than\n2400 compact sources have been extracted at 24um, nearly 100 at 70um, and 4 at\n160um. We estimate completeness limits for our 24um survey from Monte Carlo\ntests with artificial sources inserted into the Spitzer maps. We compare source\ncounts, colors, and magnitudes in the Serpens cloud to two reference data sets,\na 0.50 deg^2 set on a low-extinction region near the dark cloud, and a 5.3\ndeg^2 subset of the SWIRE ELAIS N1 data that was processed through our\npipeline. These results show that there is an easily identifiable population of\nyoung stellar object candidates in the Serpens Cloud that is not present in\neither of the reference data sets. We also show a comparison of visual\nextinction and cool dust emission illustrating a close correlation between the\ntwo, and find that the most embedded YSO candidates are located in the areas of\nhighest visual extinction.", "We show that an unification of quantum mechanics and general relativity\nimplies that there is a fundamental length in Nature in the sense that no\noperational procedure would be able to measure distances shorter than the\nPlanck length. Furthermore we give an explicit realization of an old proposal\nby Anderson and Finkelstein who argued that a fundamental length in nature\nimplies unimodular gravity. Finally, using hand waving arguments we show that a\nminimal length might be related to the cosmological constant which, if this\nscenario is realized, is time dependent.", "We derive analytic formulas for the power output and critical frequency of\nradiation by electrons accelerated by relativistic kinetic Poynting flux, and\nvalidate these results with Particle-In-Cell plasma simulations. We find that\nthe in-situ radiation power output and critical frequency are much below those\npredicted by the classical synchrotron formulae. We discuss potential\nastrophysical applications of these results.", "Short time-scale radio variations of compact extragalactic radio sources,\nknown as IntraDay Variability, can be explained in at least some sources by a\nsource-extrinsic effect, in which the variations are interpreted as\nscintillation of radio waves caused by the turbulent ISM of the Milky Way. One\nof the most convincing observational arguments in favour of propagation-induced\nvariability is the so called annual modulation of the characteristic\nvariability time-scale, which is due to the orbital motion of the Earth. Data\nfor the recently discovered and highly variable IDV source J1128+5925 are\npresented. We study the frequency and time dependence of the IDV in this\ncompact quasar. We measure the characteristic variability time-scale of the IDV\nthroughout the year, and analyze whether the observed changes in the\nvariability time-scale are consistent with annual modulation. We monitored the\nflux density variability of J1128+5925 with dense time sampling between 2.7 and\n10.45GHz with the 100m Effelsberg radio telescope of the MPIfR and with the 25m\nUrumqi radio telescope. From ten observing sessions, we determine the\nvariability characteristics and time-scales. The observed pronounced changes of\nthe variability time-scale of J1128+5925 are modelled with an anisotropic\nannual modulation model. The observed frequency dependence of the variation is\nin good agreement with the prediction from interstellar scintillation. Adopting\na simple model for the annual modulation model and using also the frequency\ndependence of the IDV, we derive a lower limit to the distance of the\nscattering screen and an upper limit to the scintillating source size. The\nlatter is found to be consistent with the measured core size from VLBI.", "Recent observational and theoretical advances concerning astronomical masers\nin star forming regions are reviewed. Major masing species are considered\nindividually and in combination. Key results are summarized with emphasis on\npresent science and future prospects.", "High resolution low-temperature absorption spectra of 0.2% Pr^3+ doped\nCsCdBr_3 were measured in the spectral region 2000--7000 cm-1. Positions and\nwidths of the crystal field levels within the 3H5, 3H4, 3F2, and 3F3 multiplets\nof the Pr^3+ main center have been determined. Hyperfine structure of several\nspectral lines has been found. Crystal field calculations were carried out in\nthe framework of the semiphenomenological exchange charge model (ECM).\nParameters of the ECM were determined by fitting to the measured total\nsplittings of the 3H4 and 3H6 multiplets and to the observed in this work\nhyperfine splittings of the crystal field levels. One- and two-phonon\nrelaxation rates were calculated using the phonon Green's functions of the\nperfect (CsCdBr_3) and locally perturbed (impurity dimer centers in\nCsCdBr_3:Pr^3+) crystal lattice. Comparison with the measured linewidths\nconfirmed an essential redistribution of the phonon density of states in\nCsCdBr_3 crystals doped with rare-earth ions.", "We present a serendipitous detection of the infrared-bright supernova remnant\n(SNR) B0104-72.3 in the Small Magellanic Cloud by the Infrared Camera (IRC)\nonboard AKARI. An elongated, partially complete shell is detected in all four\nobserved IRC bands covering 2.6-15 um. The infrared shell surrounds radio,\noptical, and X-ray emission associated with the SNR and is probably a radiative\nSNR shell. This is the first detection of a SNR shell in this near/mid-infrared\nwaveband in the Small Magellanic Cloud. The IRC color indicates that the\ninfrared emission might be from shocked H2 molecules with some possible\ncontributions from ionic lines. We conclude that B0104-72.3 is a middle-aged\nSNR interacting with molecular clouds, similar to the Galactic SNR IC 443. Our\nresults highlight the potential of AKARI IRC observations in studying SNRs,\nespecially for diagnosing SNR shocks.", "We first reported evidence for differential rotation of Kappa1 Ceti in Paper\nI. In this paper we demonstrate that the differential rotation pattern closely\nmatches that for the Sun. This result is based on additional MOST\n(Microvariability & Oscillations of STars) observations in 2004 and 2005, to\ncomplement the 2003 observations discussed in Paper I. Using StarSpotz, a\nprogram developed specifically to analyze MOST photometry, we have solved for\nk, the differential rotation coefficient, and P_{EQ}, the equatorial rotation\nperiod using the light curves from all three years. The spots range in latitude\nfrom 10 to 75 degrees and k = 0.090^{+0.006}_{-0.005} -- less than the solar\nvalue but consistent with the younger age of the star. k is also well\nconstrained by the independent spectroscopic estimate of vsini. We demonstrate\nindependently that the pattern of differential rotation with latitude in fact\nconforms to solar.\n  Details are given of the parallel tempering formalism used in finding the\nmost robust solution which gives P_{EQ} = 8.77^{+0.03}_{-0.04} days -- smaller\nthan that usually adopted, implying an age < 750 My. Our values of P_{EQ} and k\ncan explain the range of rotation periods determined by others by spots or\nactivity at a variety of latitudes. Historically, Ca II activity seems to occur\nconsistently between latitudes 50 and 60 degrees which might indicate a\npermanent magnetic feature. Knowledge of k and P_{EQ} are key to understanding\nthe dynamo mechanism and rotation structure in the convective zone as well\nassessing age for solar-type stars. We recently published values of k and\nP_{EQ} for epsilon Eri based on MOST photometry and expect to analyze MOST\nlight curves for several more spotted, solar-type stars.", "The first study of two-dimensional electron gas in surface layers on HgMnTe\nwith inverted bands is carried out experimentally and theoretically. It is\nshown that the structure of investigated capacitance magnetooscillations in\nHgMnTe MOS structures is fully similar to the one in the non-magnetic\nnarrow-gap semiconductor HgCdTe and the sole effect due to exchange interaction\nis the temperature shift of beat nodes. The information about exchange effects\nis obtained only due to our modeling of oscillations, because any pronounced\nchanges in the position of oscillations are not observed and the separate spin\ncomponents are not resolved. The Landau levels are calculated in the framework\nof concept we developed previously for the description of subband dispersions\nin zero magnetic field B=0. The new parameters (like those of $T/\\sqrt{eB}$)\narise in the theory of magnetooscillations in the semiconductors with\nquasirelativistic spectrum in contrast to the case of parabolic bands. The\nmodeling shows that the spin-orbit splitting far exceeds a contribution due to\nexchange interaction. The calculated amplitudes of ``partial'' oscillations for\ndifferent spin branches of spectrum are essentially different in accordance\nwith the observed difference in the intensity of corresponding lines in Fourier\nspectra. The comparison between experiment and theory for different\ntemperatures and parameters of exchange interaction is reported. The dominant\nmechanisms of the scattering responsible for the broadening of Landau levels\nare discussed.", "Intriguing routes to chaos have been experimentally observed in semiconductor\nsuperlattices driven by an ac field. In this work, a theoretical model of time\ndependent transport in ac driven superlattices is numerically solved. In\nagreement with experiments, distorted Poincare maps in the quasiperiodic regime\nare found. They indicate the appearance of very complex attractors and routes\nto chaos as the amplitude of the AC signal increases. Distorted maps are caused\nby the discrete well-to-well jump motion of a domain wall during spiky\nhigh-frequency self-sustained oscillations of the current.", "Recent observations of two nearby SN-less long-duration gamma-ray bursts\n(GRBs), which share no obvious characteristics in their prompt emission,\nsuggest a new phenomenological type of massive stellar death. Here we briefly\nreview the observational properties of these bursts and their proposed hosts,\nand discuss whether a new GRB classification scheme is needed.", "One way to understand the nonthermal history of the universe is by\nestablishing the origins of the unresolved and truly diffuse extragalactic\ngamma rays. Dim blazars and radio/gamma galaxies certainly make an important\ncontribution to the galactic gamma-ray background given the EGRET discoveries,\nand previous treatments are reviewed and compared with a new analysis. Studies\nof the gamma-ray intensity from cosmic rays in star-forming galaxies and from\nstructure formation shocks, as well as from dim GRBs, are briefly reviewed. A\nnew hard gamma-ray source class seems required from the predicted aggregate\nintensity compared with the measured intensity.", "An critical overview of the current state of research in turbulence in\nastrophysical disks.", "The role of the synthesis conditions on the cationic Fe/Mo ordering in\nSr2FeMoO6 double perovskite is addressed. It is shown that this ordering can be\ncontrolled and varied systematically. The Fe/Mo ordering has a profound impact\non the saturation magnetization of the material. Using the appropriate\nsynthesis protocol a record value of 3.7muB/f.u. has been obtained. Mossbauer\nanalysis reveals the existence of two distinguishable Fe sites in agreement\nwith the P4/mmm symmetry and a charge density at the Fe(m+) ions significantly\nlarger than (+3) suggesting a Fe contribution to the spin-down conduction band.\nThe implications of these findings for the synthesis of Sr2FeMoO6 having\noptimal magnetoresistance response are discussed.", "We probe turbulence structure from centimetric to metric scales by\nsimultaneous imagery at mid-infrared and visible wavelengths at the VLT\ntelescope and show that it departs significantly from the commonly used\nKolmogorov model. The data can be fitted by the von Karman model with an outer\nscale of the order of 30 m and we see clear signs of the phase structure\nfunction saturation across the 8-m VLT aperture. The image quality improves in\nthe infrared faster than the standard lambda^{-1/5} scaling and may be\ndiffraction-limited at 30-m apertures even without adaptive optics at\nwavelengths longer than 8 micron.", "We propose a new way to treat nuclear magnetism of solid $^{3}$He. We argue\nthat the magnetic interaction arises indirectly as a consequence of correlated\nzero-point motion of the ions. This motion lowers the energy of the ground\nstate, and results in a coherent state of oscillating electric dipoles.\nDistortion of the electronic wavefunctions leads to hyperfine magnetic\ninteractions with the nuclear spin.\n  Our model describes both the phonon spectra and the nuclear magnetic ordering\nof bcc $^{3}$He using a single parameter, the dipolar interaction energy\n$E_{0}$. The model yields correctly both the u2d2 symmetry of the ordered phase\nand the volume dependence of the magnetic interaction.", "We study the probability of close encounters between stars from a nuclear\ncluster and a massive black hole. The gravitational field of the system is\ndominated by the black hole in its sphere of influence. It is further modified\nby the cluster mean field (a spherical term) and a gaseous disc/torus (an\naxially symmetric term) causing a secular evolution of stellar orbits via Kozai\noscillations. Intermittent phases of large eccentricity increase the chance\nthat stars become damaged inside the tidal radius of the central hole. Such\nevents can produce debris and lead to recurring episodes of enhanced accretion\nactivity. We introduce an effective loss cone and associate it with tidal\ndisruptions during the high-eccentricity phases of the Kozai cycle. By\nnumerical integration of the trajectories forming the boundary of the loss cone\nwe determine its shape and volume. We also include the effect of relativistic\nadvance of pericentre. The potential of the disc has the efffect of enlarging\nthe loss cone and, therefore, the predicted number of tidally disrupted stars\nshould grow by factor of ~10^2. On the other hand, the effect of the cluster\nmean potential together with the relativistic pericentre advance act against\nthe eccentricity oscillations. In the end we expect the tidal disruption events\nto be approximately ten times more frequent in comparison with the model in\nwhich the three effects -- the cluster mean field, the relativistic pericentre\nadvance, and the Kozai mechanism -- are all ignored. The competition of\ndifferent influences suppresses the predicted star disruption rate as the black\nhole mass increases. Hence, the process under consideration is more important\nfor intermediate-mass black holes, M_bh~10^4M_s.", "We present B, R, and Halpha imaging data of 19 large disk galaxies whose\nproperties are intermediate between classical low surface brightness galaxies\nand ordinary high surface brightness galaxies. We use data taken from the\nLowell 1.8m Perkins telescope to determine the galaxies' overall morphology,\ncolor, and star formation properties. Morphologically, the galaxies range from\nSb through Irr and include galaxies with and without nuclear bars. The colors\nof the galaxies vary from B-R = 0.3 - 1.9, and most show at least a slight\nbluing of the colors with increasing radius. The Halpha images of these\ngalaxies show an average star formation rate lower than is found for similar\nsamples with higher surface brightness disks. Additionally, the galaxies\nstudied have both higher gas mass-to-luminosity and diffuse Halpha emission\nthan is found in higher surface brightness samples.", "Local stresses and pressures always exist in glasses.\n  In this letter we consider their effects on the structure and structural\ncorrelations in simple glasses. We find that extreme values of local pressures\nare related to well defined local structures. The correlations related to these\nextreme stresses extend to full system size and decay as a power law with the\ndistance.\n  This result is especially striking, since at large scales, the total density\nfluctuation exhibits exponentially damped decay similar to the decay in simple\nliquids. Thus at medium and large distances, the atoms with extreme values of\nlocal pressures exhibit higher degree of correlation than the rest of the\nsystem. These results were found for glasses with very different short range\nstructure, indicating their general nature.", "NGC 7679 is a nearby luminous infrared Sy2 galaxy in which starburst and AGN\nactivities co-exist. The ionization structure is maintained by both the AGN\npower-law continuum and starburst. The galaxy is a bright X-ray source\npossessing a low X-ray column density N_H < 4 x 10^20 cm^{-2}. The Compton-thin\nnature of such unabsorbed objects infers that the simple formulation of the\nUnified model for SyGs is not applicable in their case. The main goal of this\narticle is to investigate both gas distribution and ionization structure in the\ncircumnuclear region of NGC 7679 in search for the presence of a hidden Sy1\nnucleus, using the [O III] 5007 luminosity as a tracer of AGN activity. The [O\nIII] 5007 image of the NGC 7679 shows elliptical isophotes extended along the\nPA ~ 80 deg in the direction to the counterpart galaxy NGC 7682. The maximum of\nionization by the AGN power-law continuum traced by [O III] 5007/Halpha ratio\nis displaced by ~ 13 arcsec eastward from the nucleus. We conclude that the\ndust and gas in the high ionization direction has a direct view to the central\nAGN engine. This possibly results in dust/star-formation decay. A large\nfraction of the unabsorbed Compton-thin Sy2s with [O III] luminosity > 10^41\nerg s^{-1} possesses a hidden AGN source (abridged).", "For accretion rates Mdot~0.1 Msun/s to a few solar mass black hole the inner\npart of the disk is expected to make a transition from advection dominance to\nneutrino cooling. This transition is characterized by sharp changes of the disk\nproperties. I argue here that during this transition, a modest increase of the\naccretion rate leads to powerful enhancement of the Poynting luminosity of the\nGRB flow and decrease of its baryon loading. These changes of the\ncharacteristics of the GRB flow translate into changing gamma-ray spectra from\nthe photosphere of the flow. The photospheric interpretation of the GRB\nemission explains the observed narrowing of GRB pulses with increasing photon\nenergy and the luminosity-spectral peak relation within and among bursts.", "We use high-resolution hydrodynamic re-simulations to investigate the\nproperties of the thermal Sunyaev-Zel'dovich (SZ) effect from galaxy clusters.\nWe compare results obtained using different physical models for the\nintracluster medium (ICM), and show how they modify the SZ emission in terms of\ncluster profiles and scaling relations. We also produce realistic mock\nobservations to verify whether the results from hydrodynamic simulations can be\nconfirmed. We find that SZ profiles depend marginally on the modelled physical\nprocesses, while they exhibit a strong dependence on cluster mass. The central\nand total SZ emission strongly correlate with the cluster X-ray luminosity and\ntemperature. The logarithmic slopes of these scaling relations differ from the\nself-similar predictions by less than 0.2; the normalization of the relations\nis lower for simulations including radiative cooling. The observational test\nsuggests that SZ cluster profiles are unlikely to be able to probe the ICM\nphysics. The total SZ decrement appears to be an observable much more robust\nthan the central intensity, and we suggest using the former to investigate\nscaling relations.", "Since October 1, 2006, spectroscopic data from the two FORS instruments have\nbeen reduced with a new pipeline, which is based on a bottom-up calibration\napproach. I give a short description of the pipeline and discuss first\nexperiences with automatic data reduction using this software, which has\nsignificantly increased the percentage of processed data for both instruments.\nI will also describe possible new options for Quality Control.", "A failure of chips in a huge amount of modern electronic devices is connected\nas a rule with the undesirable capturing of charge (electrons and holes) by\ntraps in a thin insulating film of silicon oxide in transistors. It leads to a\nbreakdown of transistors or to a destructive change of their characteristics.\nIt is suggested that silicon oxide will be replaced in the next generation of\nnanoscale devices by silicon oxynitride. Therefore, it is very important to\nunderstand the nature of traps in this material. We discuss this nature using\nthe quantum-chemical simulation.", "We report on the creation of Bose-Einstein condensates of $^{87}$Rb in a\nspecially designed hybrid, dipole and magnetic trap. This trap naturally allows\nthe coherent transfer of matter waves into a pure dipole potential waveguide\nbased on a doughnut beam. Specifically, we present studies of the coherence of\nthe ensemble in the hybrid trap and during the evolution in the waveguide by\nmeans of an autocorrelation interferometer scheme. By monitoring the expansion\nof the ensemble in the waveguide we observe a mean field dominated acceleration\non a much longer time scale than in the free 3D expansion. Both the\nautocorrelation interference and the pure expansion measurements are in\nexcellent agreement with theoretical predictions of the ensemble dynamics.", "Density-functional calculations are presented for high-pressure structural\nphases of S and Se. The structural phase diagrams, phonon spectra,\nelectron-phonon coupling, and superconducting properties of the isovalent\nelements are compared. We find that with increasing pressure, Se adopts a\nsequence of ever more closely packed structures (beta-Po, bcc, fcc), while S\nfavors more open structures (beta-Po, simple cubic, bcc). These differences are\nshown to be attributable to differences in the S and Se core states. All the\ncompressed phases of S and Se considered are calculated to have weak to\nmoderate electron-phonon coupling strengths consistent with superconducting\ntransition temperatures in the range of 1 to 20 K. Our results compare well\nwith experimental data on the beta-Po --> bcc transition pressure in Se and on\nthe superconducting transition temperature in beta-Po S. Further experiments\nare suggested to search for the other structural phases predicted at higher\npressures and to test theoretical results on the electron-phonon interaction\nand superconducting properties.", "We report infrared photometry of the extrasolar planet HD 209458b during the\ntime of secondary eclipse (planet passing behind the star). Observations were\nacquired during two secondary eclipses at the NASA Infrared Telescope Facility\n(IRTF) in September 2003. We used a circular variable filter (1.5-percent\nbandpass) centered at 3.8 microns to isolate the predicted flux peak of the\nplanet at this wavelength. Residual telluric absorption and instrument\nvariations were removed by offsetting the telescope to nearby bright comparison\nstars at a high temporal cadence. Our results give a secondary eclipse depth of\n0.0013 +/- 0.0011, not yet sufficient precision to detect the eclipse, whose\nexpected depth is approximately 0.002 - 0.003. We here elucidate the current\nobservational limitations to this technique, and discuss the approach needed to\nachieve detections of hot Jupiter secondary eclipses at 3.8 microns from the\nground.", "Hundreds of substellar companions to solar-type stars will be discovered with\nthe Kepler satellite. Kepler's extreme photometric precision gives access to\nlow-amplitude stellar variability contributed by a variety of physical\nprocesses. We discuss in detail the periodic flux modulations arising from the\ntidal force on the star due to a substellar companion. An analytic expression\nfor the variability is derived in the equilibrium-tide approximation. We\ndemonstrate analytically and through numerical solutions of the linear,\nnonadiabatic stellar oscillation equations that the equilibrium-tide formula\nworks extremely well for stars of mass <1.4 Msun with thick surface convection\nzones. More massive stars with largely radiative envelopes do not conform to\nthe equilibrium-tide approximation and can exhibit flux variations $\\ga$10\ntimes larger than naive estimates. Over the full range of stellar masses\nconsidered, we treat the oscillatory response of the convection zone by\nadapting a prescription that A. J. Brickhill developed for pulsating white\ndwarfs. Compared to other sources of periodic variability, the ellipsoidal\nlightcurve has a distinct dependence on time and system parameters. We suggest\nthat ellipsoidal oscillations induced by giant planets may be detectable from\nas many as ~100 of the 10^5 Kepler target stars. (Abridged)", "We study the equilibrium dynamics of a weakly interacting Bose-Einstein\ncondensate trapped in a box. In our approach we use a semiclassical\napproximation similar to the description of a multi-mode laser. In dynamical\nequations derived from a full N-body quantum Hamiltonian we substitute all\ncreation (and annihilation) operators (of a particle in a given box state) by\nappropriate c-number amplitudes. The set of nonlinear equations obtained in\nthis way is solved numerically. We show that on the time scale of a few\nmiliseconds the system exhibits relaxation - reaches an equilibrium with\npopulations of different eigenstates fluctuating around their mean values.", "We present an algorithm to calculate the linear response of periodic systems\nin the time-dependent density functional thoery, using a real-space\nrepresentation of the electron wave functions and calculating the dynamics in\nreal time. The real-space formulation increases the efficiency for calculating\nthe interaction, and the real-time treatment decreases storage requirements and\nthe allows the entire frequency-dependent response to be calculated at once. We\ngive as examples the dielectric functions of a simple metal, lithium, and an\nelemental insulator, diamond.", "We present predictions for the evolution of the galaxy luminosity function,\nnumber counts and redshift distributions in the IR based on the Lambda-CDM\ncosmological model. We use the combined GALFORM semi-analytical galaxy\nformation model and GRASIL spectrophotometric code to compute galaxy SEDs\nincluding the reprocessing of radiation by dust. The model, which is the same\nas that in Baugh et al (2005), assumes two different IMFs: a normal solar\nneighbourhood IMF for quiescent star formation in disks, and a very top-heavy\nIMF in starbursts triggered by galaxy mergers. We have shown previously that\nthe top-heavy IMF seems to be necessary to explain the number counts of faint\nsub-mm galaxies. We compare the model with observational data from the SPITZER\nSpace Telescope, with the model parameters fixed at values chosen before\nSPITZER data became available. We find that the model matches the observed\nevolution in the IR remarkably well over the whole range of wavelengths probed\nby SPITZER. In particular, the SPITZER data show that there is strong evolution\nin the mid-IR galaxy luminosity function over the redshift range z ~ 0-2, and\nthis is reproduced by our model without requiring any adjustment of parameters.\nOn the other hand, a model with a normal IMF in starbursts predicts far too\nlittle evolution in the mid-IR luminosity function, and is therefore excluded.", "The connected system of Boltzman equations for the interacting system of\nelectrons, positrons and photons in high external electric E and arbitrary\nmagnetic H fields is solved. The consideration is made under the conditions of\narbitrary heating and the mutual drag of carriers and photons.\n  The non-stationary and non-uniform distribution function (DF) of photons for\nthe all considered cases is obtained. It is shown that the DF of photons have\nthe stationary limit for the drift velocities $(\\overset{\\to\n}\\to{u}\\overset{\\to}\\to{q}/\\hbar \\omega_q) <1$ and becomes exponentially grown\nby the time for the drift velocities\n$(\\overset{\\to}\\to{u}\\overset{\\to}\\to{q}/\\hbar \\omega_q) \\geq 1$. It is shown\nthat the mutual drag of carriers and photons leads to the formation of\n''quasi-particles''\\_ the ''electron dressed by photons'' and ''positron\ndressed by photons'', i.e. the mutual drag plays the role of the dressing\nmechanism of carriers and leads to the renormalization of the mass and\nfrequency of photons.\n  As a result of analyses of the phenomena of connected by the mutual drag\nsystem of carriers and photons we receive some fundamental results: a) the\nfiniteness of the mass of photon (i.e. the rest mass of photons do not equal to\nzero); b) reality of takhyons as a quasi-particles with the real mass in\namplifying system (or regime); c) identity of the mechanism of relativity and\nthe Doppler effect which coincides with the renormalization of frequency or\nmass as a result of the mutual drag of carriers and photons at external field\n(force). These conclusions were received as a result of the fact that the\nrelativistic factor enters to the expressions of the DF of photons and other\nphysical expressions in the first order in the form $[ 1-(u^2/c^2) ] ^{-1}$,\ninstead the $[ 1-(u^2/c^2) ] ^{-1/2}$ in Einstein theory. It is shown that the\nrelativistic effect of deceleration of time really taking place for the\nrelaxation time of carriers or for the life time of carriers, or for the period\nof electromagnetic oscillations. The latest is a direct result of the Doppler\neffect. Also it is shown that the velocity of light is an averaged velocity of\nphotons at the ground state, as well as a velocity of sound for the phonons.", "This Letter reports on 3-dimensional simulations of Kerr black hole\nmagnetospheres that obey the general relativistic equations of perfect\nmagnetohydrodynamics (MHD). In particular, we study powerful Poynting flux\ndominated jets that are driven from dense gas in the equatorial plane in the\nergosphere. The physics of which has been previously studied in the simplified\nlimit of an ergopsheric disk. For high spin black holes, $a/M > 0.95$, the\nergospheric disk is prominent in the 3-D simulations and is responsible for\ngreatly enhanced Poynting flux emission. Any large scale poloidal magnetic flux\nthat is trapped in the equatorial region leads to an enormous release of\nelectromagnetic energy that dwarfs the jet energy produced by magnetic flux\nthreading the event horizon. The implication is that magnetic flux threading\nthe equatorial plane of the ergosphere is a likely prerequisite for the central\nengine of powerful FRII quasars.", "The close analogy between cluster percolation and string proliferation in the\ncontext of critical phenomena is studied. Like clusters in percolation theory,\nclosed strings, which can be either finite-temperature worldlines or\ntopological line defects, are described by a distribution parametrized by only\ntwo exponents. On approaching the critical point, the string tension vanishes,\nand the loops proliferate thereby signalling the onset of Bose-Einstein\ncondensation (in case of worldlines) or the disordering of the ordered state\n(in case of vortices). The ideal Bose gas with modified energy spectrum is used\nas a stepping stone to derive general expressions for the critical exponents in\nterms of the two exponents parameterizing the loop distribution near\ncriticality.", "We observed 34 comets using the 24 micron camera on the Spitzer Space\nTelescope. Each image contains the nucleus and covers at least 10^6 km of each\ncomet's orbit. Debris trails due to mm-sized or larger particles were found\nalong the orbits of 27 comets; 4 comets had small-particle dust tails and a\nviewing geometry that made debris trails impossible to distinguish; and only 3\nhad no debris trail despite favorable observing conditions. There are now 30\nJupiter-family comets with known debris trails, of which 22 are reported in\nthis paper for the first time. The detection rate is >80%, indicating that\ndebris trails are a generic feature of short-period comets. By comparison to\norbital calculations for particles of a range of sizes ejected over 2 yr prior\nto observation, we find that particles comprising 4 debris trails are typically\nmm-sized while the remainder of the debris trails require particles larger than\nthis. The lower-limit masses of the debris trails are typically 10^11 g, and\nthe median mass loss rate is 2 kg/s. The mass-loss rate in trail particles is\ncomparable to that inferred from OH production rates and larger than that\ninferred from visible-light scattering in comae.", "One dimensional system of Dirac fermions with a random-varying mass is\nstudied by the transfer-matrix methods which we developed recently. We\ninvestigate the effects of nonlocal correlation of the spatial-varying Dirac\nmass on the delocalization transition. Especially we numerically calculate both\nthe \"typical\" and \"mean\" localization lengths as a function of energy and the\ncorrelation length of the random mass. To this end we introduce an imaginary\nvector potential as suggested by Hatano and Nelson and solve the eigenvalue\nproblem. Numerical calculations are in good agreement with the results of the\nanalytical calculations.", "We present a theory of carrier-induced ferromagnetism in diluted magnetic\nsemiconductors (III_{1-x} Mn_x V) which allows for arbitrary itinerant-carrier\nspin polarization and dynamic correlations. Both ingredients are essential in\nidentifying the system's elementary excitations and describing their\nproperties. We find a branch of collective modes, in addition to the spin waves\nand Stoner continuum which occur in metallic ferromagnets, and predict that the\nlow-temperature spin stiffness is independent of the strength of the exchange\ncoupling between magnetic ions and itinerant carriers. We discuss the\ntemperature dependence of the magnetization and the heat capacity.", "Light and cold extrasolar planets such as OGLE 2005-BLG-390Lb, a 5.5\nEarth-mass planet detected via microlensing, could be frequent in the Galaxy\naccording to some preliminary results from microlensing experiments. These\nplanets can be frozen rocky- or ocean-planets, situated beyond the snow line\nand, therefore, beyond the habitable zone of their system. They can nonetheless\nhost a layer of liquid water, heated by radiogenic energy, underneath an ice\nshell surface for billions of years, before freezing completely. These results\nsuggest that oceans under ice, like those suspected to be present on icy moons\nin the Solar system, could be a common feature of cold low-mass extrasolar\nplanets.", "The extended lobes of radio galaxies are examined as sources of X-ray and\ngamma-ray emission via inverse Compton scattering of 3K background photons. The\nCompton spectra of two exemplary examples, Fornax A and Centaurus A, are\nestimated using available radio measurements in the ~10's MHz - 10's GHz range.\nFor average lobe magnetic fields of >~0.3-1 micro-G, the lobe spectra are\npredicted to extend into the soft gamma-rays making them likely detectable with\nthe GLAST LAT. If detected, their large angular extents (~1 deg and 8 deg) will\nmake it possible to ``image'' the radio lobes in gamma-rays. Similarly, this\nprocess operates in more distant radio galaxies and the possibility that such\nsystems will be detected as unresolved gamma-ray sources with GLAST is briefly\nconsidered.", "Magnetotransport has been investigated in high purity bismuth crystals in\nstatic magnetic fields as high as 20 T and temperatures as low as 25 mK. This\nhigh B/T ratio permits observation of pronounced Shubnikov-de Haas oscillations\nover a wide field range and up to fields where most of the carriers are in the\nlowest Landau level. For transport currents in the bisectrix or binary\ndirections and field in the perpendicular trigonal direction, we have observed\ndoublet splittings centered on each Shubnikov-de Haas oscillation. These\nsplittings exhibit a quadratic dependence on field and disappear before the\nlast oscillation. Our observations allow us to conclude unambiguously that\nalready when the Landau level index is as high as 2 the carriers are fully\npolarized and that the g-factor for holes with the field in the trigonal\ndirection is 35.3(4).", "We derive the equation of motion for the velocity fluctuations of a 2D\ndeformed trapped Bose gas above the critical temperature in the hydrodynamical\nregime. From this equation, we calculate the eigenfrequencies for a few\nlow-lying excitation modes. Using the method of averages, we derive a\ndispersion relation in a deformed trap that interpolates between the\ncollisionless and hydrodynamic regimes. We make use of this dispersion relation\nto calculate the frequencies and the damping rates for monopole and quadrupole\nmode in both the regimes. We also discuss the time evolution of the wave packet\nwidth of a Bose gas in a time dependent as well as time independent trap.", "In the coming decades, research in extrasolar planets aims to advance two\ngoals: 1) detecting and characterizing low-mass planets increasingly similar to\nthe Earth, and 2) improving our understanding of planet formation. We present a\nnew planet detection method that is capable of making large advances towards\nboth of these objectives and describe a modest network of telescopes that is\nable to make the requisite observations. In a system where a known planet\ntransits its host star, a second planet in that system will cause the time\nbetween transits to vary. These transit timing variations can be used to infer\nthe orbital elements and mass of the perturbing planet even if it has a mass\nthat is smaller than the mass of the Earth. This detection technique\ncomplements other techniques because it is most sensitive in mean-motion\nresonances where, due to degeneracies, other techniques have reduced\nsensitivity. Small ground-based observatories have already exceeded the\nphotometric precision necessary to detect sub-Earth mass planets. However, TTV\nplanet searches are currently limited by the relatively small number of\nhigh-precision transit data and insufficient observing time on existing\ntelescopes. These issues will be compounded as the number of known transiting\nplanets suitable for TTV study will increase substantially in the near future.\nA relatively modest investment in a ground-based network of small ($\\sim 0.5\n{\\rm m}$ telescopes could provide the needed coverage and so dramatically\nincrease the effectiveness of transit timing observations.", "Context. The most recent determination of the solar chemical composition,\nusing a time-dependent, 3D hydrodynamical model of the solar atmosphere,\nexhibits a significant decrease of C, N, O abundances compared to their\nprevious values. Solar models that use these new abundances are not consistent\nwith helioseismological determinations of the sound speed profile, the surface\nhelium abundance and the convection zone depth. Aims. We investigate the effect\nof changes of solar abundances on low degree p-mode and g-mode characteristics\nwhich are strong constraints of the solar core. We consider particularly the\nincrease of neon abundance in the new solar mixture in order to reduce the\ndiscrepancy between models using new abundances and helioseismology. Methods.\nThe observational determinations of solar frequencies from the GOLF instrument\nare used to test solar models computed with different chemical compositions. We\nconsider in particular the normalized small frequency spacings in the low\ndegree p-mode frequency range. Results. Low-degree small frequency spacings are\nvery sensitive to changes in the heavy-element abundances, notably neon. We\nshow that by considering all the seismic constraints, including the small\nfrequency spacings, a rather large increase of neon abundance by about (0.5 +/-\n0.05)dex can be a good solution to the discrepancy between solar models that\nuse new abundances and low degree helioseismology, subject to adjusting\nslightly the solar age and the highest abundances. We also show that the change\nin solar abundances, notably neon, considerably affects g-mode frequencies,\nwith relative frequency differences between the old and the new models higher\nthan 1.5%", "Using a theory which treats on equal footing transport of excited electrons\nand electron-phonon scattering, we are able to explain the temperature\ndependence of the relaxation time in Cu as recently observed by Petek, Nagano,\nand Ogawa. We show that the unexpected increase of the relaxation time with\ntemperature results from the drastic change of the electron motion due to the\nefficiency of electron-phonon scattering: the transport is ballistic at low\ntemperature and gets diffusive at room temperature. Finally, our theory also\nreproduces the experimental measurements of the two-photon photoemission (2PPE)\nintensity as a function of the pump-probe delay.", "The status of 38 halo white dwarf candidates identified by Oppenheimer et al.\n(2001) has been intensively discussed by various authors. In analyses\nundertaken to date, trigonometric parallaxes are crucial missing data. Distance\nmeasurements are mandatory to kinematically segregate halo object from disk\nobjects and hence enable a more reliable estimate of the local density of halo\ndark matter residing in such objects.\n  We present trigonometric parallax measurements for 15 candidate halo white\ndwarfs (WDs) selected from the Oppenheimer et al. (2001) list. We observed the\nstars using the ESO 1.56-m Danish Telescope and ESO 2.2-m telescope from August\n2001 to July 2004. Parallaxes with accuracies of 1--2 mas were determined\nyielding relative errors on distances of $\\sim5$% for 6 objects, $\\sim12$% for\n3 objects, and $\\sim20$% for two more objects. Four stars appear to be too\ndistant (probably farther than 100 pc) to have measurable parallaxes in our\nobservations. Distances, absolute magnitudes and revised space velocities were\nderived for the 15 halo WDs from the Oppenheimer et al. (2001) list. Halo\nmembership is confirmed unambiguously for 6 objects while 5 objects may be\nthick disk members and 4 objects are too distant to draw any conclusion based\nsolely on kinematics. Comparing our trigonometric parallaxes with photometric\nparallaxes used in previous work reveals an overestimation of distance as\nderived from photometric techniques. This new data set can be used to revise\nthe halo white dwarf space density, and that analysis will be presented in a\nsubsequent publication.", "We study the growth of a reference network with aging of sites defined in the\nfollowing way. Each new site of the network is connected to some old site with\nprobability proportional (i) to the connectivity of the old site as in the\nBarab\\'{a}si-Albert's model and (ii) to $\\tau^{-\\alpha}$, where $\\tau$ is the\nage of the old site. We consider $\\alpha$ of any sign although reasonable\nvalues are $0 \\leq \\alpha \\leq \\infty$. We find both from simulation and\nanalytically that the network shows scaling behavior only in the region $\\alpha\n< 1$. When $\\alpha$ increases from $-\\infty$ to 0, the exponent $\\gamma$ of the\ndistribution of connectivities ($P(k) \\propto k^{-\\gamma}$ for large $k$) grows\nfrom 2 to the value for the network without aging, i.e. to 3 for the\nBarab\\'{a}si-Albert's model. The following increase of $\\alpha$ to 1 makes\n$\\gamma$ to grow to $\\infty$. For $\\alpha>1$ the distribution $P(k)$ is\nexponentional, and the network has a chain structure.", "SkyMapper is amongst the first of a new generation of dedicated, wide-field\nsurvey telescopes. The 1.3m SkyMapper telescope features a 5.7 square degree\nfield-of-view Cassegrain imager and will see first light in late 2007. The\nprimary goal of the facility is to conduct the Southern Sky Survey a six\ncolour, six epoch survey of the southern sky. The survey will provide\nphotometry for objects between 8th and 23rd magnitude with global photometric\naccuracy of 0.03 magnitudes and astrometry to 50 mas. This will represent a\nvaluable scientific resource for the southern sky and in addition provide a\nbasis for photometric and astrometric calibration of imaging data.", "We analysed the ground state energy of some dimerized spin-1/2 transverse XX\nand Heisenberg chains with Dzyaloshinskii-Moriya (DM) interaction to study the\ninfluence of the latter interaction on the spin-Peierls instability. We found\nthat DM interaction may act either in favour of the dimerization or against it.\nThe actual result depends on the dependence of DM interaction on the distortion\namplitude in comparison with such dependence for the isotropic exchange\ninteraction.", "We present wide-field JHKs-band photometric observations of the three compact\nHII regions G48.9-0.3, G49.0-0.3, and G49.2-0.3 in the active star-forming\nregion W51B. The star clusters inside the three compact HII regions show the\nexcess number of stars in the J-Ks histograms compared with reference fields.\nWhile the mean color excess ratio E(J-H)/E(H-Ks) of the three compact HII\nregions are similar to ~ 2.07, the visual extinctions toward them are somewhat\ndifferent: ~ 17 mag for G48.9-0.3 and G49.0-0.3; ~ 23 mag for G49.2-0.3. Based\non their sizes and brightnesses, we suggest that the age of each compact HII\nregion is =< 2 Myr. The inferred total stellar mass, ~ 1.4 x 10^4 M_sun, of\nW51B makes it one of the most active star forming regions in the Galaxy with\nthe star formation efficiency of ~ 10 %.", "We present estimates of the N-point galaxy, area-averaged, angular\ncorrelation functions $\\bar{\\omega}_{N}$($\\theta$) for $N$ = 2,...,7 for\ngalaxies from the fifth data release of the Sloan Digital Sky Survey. Our\nparent sample is selected from galaxies with $18 \\leq r < 21$, and is the\nlargest ever used to study higher-order correlations. We subdivide this parent\nsample into two volume limited samples using photometric redshifts, and these\ntwo samples are further subdivided by magnitude, redshift, and color (producing\nearly- and late-type galaxy samples) to determine the dependence of\n$\\bar{\\omega}_{N}$($\\theta$) on luminosity, redshift, and galaxy-type. We\nmeasure $\\bar{\\omega}_{N}$($\\theta$) using oversampling techniques and use them\nto calculate the projected, $s_{N}$. Using models derived from theoretical\npower-spectra and perturbation theory, we measure the bias parameters $b_1$ and\n$c_2$, finding that the large differences in both bias parameters ($b_1$ and\n$c_2$) between early- and late-type galaxies are robust against changes in\nredshift, luminosity, and $\\sigma_8$, and that both terms are consistently\nsmaller for late-type galaxies. By directly comparing their higher-order\ncorrelation measurements, we find large differences in the clustering of\nlate-type galaxies at redshifts lower than 0.3 and those at redshifts higher\nthan 0.3, both at large scales ($c_2$ is larger by $\\sim0.5$ at $z > 0.3$) and\nsmall scales (large amplitudes are measured at small scales only for $z > 0.3$,\nsuggesting much more merger driven star formation at $z > 0.3$). Finally, our\nmeasurements of $c_2$ suggest both that $\\sigma_8 < 0.8$ and $c_2$ is negative.", "The intrinsic fraction of broad absorption line quasars (BALQSOs) is\nimportant in constraining geometric and evolutionary models of quasars. We\npresent the fraction of BALQSOs in 2MASS detected quasars within the SDSS DR3\nsample in the redshift range of 1.7 < z < 4.38. The fraction of BALQSOs is\n40.4^{+3.4}_{-3.3}% in the 2MASS 99% database K_s band completeness sample, and\n38.5^{+1.7}_{-1.7}% in the larger 2MASS sample extending below the completeness\nlimit. These fractions are significantly higher than the 26% reported in the\noptical bands for the same parent sample. We also present the fraction of\nBALQSOs as functions of apparent magnitudes, absolute magnitudes, and redshift\nin the 2MASS and SDSS bands. The 2MASS fractions are consistently higher than\nthe SDSS fractions in every comparison, and the BALQSO fractions steadily\nincrease with wavelength from the SDSS u to the 2MASS K_s bands. Furthermore,\nthe i - K_s color distributions of BALQSOs and non-BALQSOs indicate that\nBALQSOs are redder than non-BALQSOs, with a K-S test probability of 2e-12.\nThese results are consistent with the spectral difference between BALQSOs and\nnon-BALQSOs including both the absorption troughs and dust extinction in\nBALQSOs, which leads to significant selection biases against BALQSOs in the\noptical bands. Using a simple simulation incorporating the luminosity function\nof quasars and the amount of obscuration for BALQSOs, we simultaneously fit the\nBALQSO fractions in the SDSS and 2MASS bands. We obtain a true BALQSO fraction\nof 43\\pm2% for luminous quasars (M_{K_s} \\lesssim -30.1 mag).", "Metallic thin film ferromagnets generically possess spiral states that carry\ndissipationless spin currents. We relate the critical values of these\nsupercurrents to micromagnetic material parameters, identify the circumstances\nunder which the supercurrents will be most robust, and propose experiments\nwhich could reveal this new collective transport behavior.", "We have observed the ultra-compact low-mass X-ray binary (LMXB) 1A 1246-588\nwith the Rossi X-ray Timing Explorer (RXTE). In this manuscript we report the\ndiscovery of a kilohertz quasi-periodic oscillation (QPO) in 1A 1246-588. The\nkilohertz QPO was only detected when the source was in a soft high-flux state\nreminiscent of the lower banana branch in atoll sources. Only one kilohertz QPO\npeak is detected at a relatively high frequency of 1258+-2 Hz and at a single\ntrial significance of more than 7 sigma. Kilohertz QPOs with a higher frequency\nhave only been found on two occasions in 4U 0614+09. Furthermore, the frequency\nis higher than that found for the lower kilohertz QPO in any source, strongly\nsuggesting that the QPO is the upper of the kilohertz QPO pair often found in\nLMXBs. The full-width at half maximum is 25+-4 Hz, making the coherence the\nhighest found for an upper kilohertz QPO. From a distance estimate of ~6 kpc\nfrom a radius expansion burst we derive that 1A 1246-588 is at a persistent\nflux of ~0.2-0.3 per cent of the Eddington flux, hence 1A 1246-588 is one of\nthe weakest LMXBs for which a kilohertz QPO has been detected. The\nroot-mean-square (rms) amplitude in the 5-60 keV band is 27+-3 per cent, this\nis the highest for any kilohertz QPO source so far, in line with the general\nanti-correlation between source luminosity and rms amplitude of the kilohertz\nQPO peak identified before. Using the X-ray spectral information we produce a\ncolour-colour diagram. The source behaviour in this diagram provides further\nevidence for the atoll nature of the source.", "The axial next-nearest neighbour Ising (ANNNI) model is studied for thin\nfilms of up to $L= 10$ layers, with a distinct phase diagram for each film\nthickness. The systematics of the ordered phases, as obtained from mean-field\ntheory, Monte Carlo simulations, and low temperature expansions, is discussed.\nResults are compared to those for the ANNNI model in the limit $L\n\\longrightarrow \\infty$.", "We consider quantum superposition states in Bose-Einstein condensates. A\ndecoherence rate for the Schr\\\"odinger cat is calculated and shown to be a\nsignificant threat to this macroscopic quantum superposition of BEC's. An\nexperimental scenario is outlined where the decoherence rate due to the thermal\ncloud is dramatically reduced thanks to trap engineering and \"symmetrization\"\nof the environment. We show that under the proposed scenario the Schroedinger\ncat belongs to an approximate decoherence-free pointer subspace. This paper is\na simplified and more pedagogical version of our previous work, Phys.Rev. A62,\n13607 (2000).", "We present a parameter-free model which estimates the density of excitons in\nCu$_2$O, related to experiments that have tried to create an excitonic\nBose-Einstein condensate. Our study demonstrates that the triplet-state\nexcitons move along adiabats and obey classical statistics, while the\nsinglet-state excitons are a possible candidate for forming a Bose-Einstein\ncondensate. Finally we show that the results of this study do not change\nqualitatively in a two-dimensional exciton gas, which can be realized in a\nquantum well.", "The behavior of collective oscillations of a trapped boson-fermion mixed\ncondensate is studied in the sum rule approach. Mixing angle of bosonic and\nfermionic multipole operators is introduced so that the mixing characters of\nthe low-lying collective modes are studied as functions of the boson-fermion\ninteraction strength. For an attractive boson-fermion interaction, the\nlow-lying monopole mode becomes a coherent oscillation of bosons and fermions\nand shows a rapid decrease in the excitation energy towards the instability\npoint of the ground state. In contrast, the low-lying quadrupole mode keeps a\nbosonic character over a wide range of the interaction strengths. For the\ndipole mode the boson-fermion in-phase oscillation remains to be the eigenmode\nunder the external oscillator potential. For weak repulsive values of the\nboson-fermion interaction strengths we found that an average energy of the\nout-of-phase dipole mode stays lower than the in-phase oscillation.\n  Physical origin of the behavior of the multipole modes against boson-fermion\ninteraction strength is discussed in some detail.", "We report, through experimental observations and computer simulations, that\natomic lattice interlocking can determine whether an object rolls or slides on\na surface. We have quantitatively manipulated carbon nanotubes (CNTs) on a\nvariety of substrates with an atomic force microscope (AFM) and observe rolling\nto occur only on graphite. We measure the forces when the CNT is in-registry\nwith the graphite lattice, and observe rolling only in this lock-in state.\nAtomistic computer simulations identify the energy barriers for sliding and\nrolling, elucidate atomic-scale features of slip-roll motion, and explain the\ndetails of the lateral force data in terms of the intrinsic faceting of\nmultiwall CNTs.", "Accretion-powered X-ray pulsars are among the most luminous X-ray sources in\nthe Galaxy. However, despite decades of theoretical and observational work\nsince their discovery, no satisfactory model for the formation of the observed\nX-ray spectra has emerged. In this paper, we report on a self-consistent\ncalculation of the spectrum emerging from a pulsar accretion column that\nincludes an explicit treatment of the bulk and thermal Comptonization occurring\nin the radiation-dominated shocks that form in the accretion flows. Using a\nrigorous eigenfunction expansion method, we obtain a closed-form expression for\nthe Green's function describing the upscattering of monochromatic radiation\ninjected into the column. The Green's function is convolved with\nbremsstrahlung, cyclotron, and blackbody source terms to calculate the emergent\nphoton spectrum. We show that energization of photons in the shock naturally\nproduces an X-ray spectrum with a relatively flat continuum and a high-energy\nexponential cutoff. Finally, we demonstrate that our model yields good\nagreement with the spectra of the bright pulsar Her X-1 and the low luminosity\npulsar X Per.", "We calculate a grand partition function of the attractive Bose gas in the\ninfinite space within some approximations. Using the idea of the Yang-Lee\nzeros, it is proved that the gas-liquid condensation occurs before the\nconventional condition of the Bose-Einstein condensation is satisfied. Further,\nit is pointed out that Bosons with a zero momentum play a role of a trigger to\nthis gas-liquid condensation. We discuss its implication to the trapped atomic\ngas.", "We performed an experiment on elementary hydrodynamics. The basic system is a\ncylindrical bottle from which water flows through a pin-hole located at the\nbottom of its lateral surface. We measured the speed of the water leaving the\npin-hole, as a function of both the time and the current level of water still\ninside the bottle. The experimental results are compared with the theory. The\ntheoretical treatment is a very simple one based on mass and energy\nconservation, corresponding to a widespread exercise usually adopted in\nuniversity basic disciplines of Physics.\n  We extended the previous experiment to another similar system using two equal\nbottles with equal pin-holes. The water flowing from the first bottle feeds the\nsecond one located below it. The same concepts of mass and energy conservation\nnow lead to a non-trivial differential equation for the lowest bottle dynamics.\nWe solved this equation both numerically and analytically, comparing the\nresults with the experimental data.", "Using the numerical approach for a study of the thermodynamic properties of\nthe nonuniform one-dimensional spin-1/2 isotropic XY model in a transverse\nfield we examine different lattice distortions to reveal which spin-Peierls\nphases are realized in the magnetic chain at zero temperature in the presence\nof external field.", "We present the results of six-epoch Very Long Baseline Array (VLBA)\nobservations of 3C~66A. The high-resolution Very Long Baseline Interferometer\n(VLBI) maps obtained at multi-frequency (2.3, 8.4, and 22.2 GHz) simultaneously\nenabled us to identify the brightest compact component with the core. We find\nthat the spectrum of the core can be reasonably fitted by the synchrotron\nself-absorption model. Our VLBA maps show that the jet of 3C~66A has two\nbendings at about 1.2 and 4 mas from the core. We also give possible\nidentifications of our jet components with the components in previous VLBA\nobservations by analysing their proper motions. We find consistent differences\nof the position from the core in one component between different frequencies at\nsix epochs.", "We present numerically exact energy estimates for two-dimensional electrons\nin a parabolic confinement. By application of an extension of the recently\nintroduced many-body diffusion algorithm, the ground-state energies are\nsimulated very efficiently. The new algorithm relies on partial\nantisymmetrization under permutation of particle coordinates. A comparison is\nmade with earlier theoretical results for that system.", "It has long been speculated that supernova remnants represent a major source\nof cosmic rays in the Galaxy. Observations over the past decade have\nceremoniously unveiled direct evidence of particle acceleration in SNRs to\nenergies approaching the knee of the cosmic ray spectrum. Nonthermal X-ray\nemission from shell-type SNRs reveals multi-TeV electrons, and the dynamical\nproperties of several SNRs point to efficient acceleration of ions.\nObservations of TeV gamma-ray emission have confirmed the presence of energetic\nparticles in several remnants as well, but there remains considerable debate as\nto whether this emission originates with high energy electrons or ions. Equally\nuncertain are the exact conditions that lead to efficient particle\nacceleration.\n  Based on the catalog of EGRET sources, we know that there is a large\npopulation of Galactic gamma-ray sources whose distribution is similar to that\nof SNRs. With the increased resolution and sensitivity of GLAST, the gamma-ray\nSNRs from this population will be identified. Their detailed emission\nstructure, along with their spectra, will provide the link between their\nenvironments and their spectra in other wavebands to constrain emission models\nand to potentially identify direct evidence of ion acceleration in SNRs. Here I\nsummarize recent observational and theoretical work in the area of cosmic ray\nacceleration by SNRs, and discuss the contributions GLAST will bring to our\nunderstanding of this problem.", "The Kilodegree Extremely Little Telescope (KELT) project is a survey for\nplanetary transits of bright stars. It consists of a small-aperture, wide-field\nautomated telescope located at Winer Observatory near Sonoita, Arizona. The\ntelescope surveys a set of 26 x 26 degree fields, together covering about 25%\nof the Northern sky, targeting stars in the range of 8<V<10 mag, searching for\ntransits by close-in Jupiters. This paper describes the system hardware and\nsoftware and discusses the quality of the observations. We show that KELT is\nable to achieve the necessary photometric precision to detect planetary\ntransits around solar-type main sequence stars.", "We propose a MIDEX-class space mission with the goal to find and characterize\nroughly 10,000 transiting planets. When transits occur, a much more detailed\ncharacterization of the planet is possible and so a large data base of\ntransiting planets will provide planets with a large range in periods and radii\nfor follow-up studies. Our survey will be all-sky and focused on stars brighter\nthan V=14.8. Down to V=12, LEAVITT will be able to detect Neptune-sized\nobjects. Because of it's high cadence, LEAVITT is about 100 times more\nsensitive at detecting transits than GAIA, while it will find more than 20\ntimes as many transits as KEPLER. LEAVITT has multi-band photometric capability\nimplemented via a low-resolution dispersive element which can obtain 0.2% (2\nmmag) photometry down to V=14.8. LEAVITT's high multi-band photometric accuracy\nreduces the number of false-positives significantly.", "We consider a Statistical Mechanics approach to granular systems by following\nthe original ideas developed by Edwards. We use the concept of ``inherent\nstates'', defined as the stable configurations in the potential energy\nlandscape, introduced in the context of glasses. Under simplifying assumptions,\nthe equilibrium inherent states can be characterised by a configurational\ntemperature, $1/\\beta$. We link $\\beta$ to Edwards' compactivity and address\nthe problem of its experimental measure. We also discuss the possibility to\ndescribe the time dependent distribution probability in the inherent states\nwith an appropriate master equation.", "Angular momentum can be transferred to a trapped Bose-Einstein condensate by\ndistorting its shape with an external rotating field, provided the rotational\nfrequency is larger than a critical frequency fixed by the energy and angular\nmomentum of the excited states of the system. By using the Gross-Pitaevskii\nequation and sum rules, we explore the dependence of such a critical frequency\non the multipolarity of the excitations and the asymmetry of the confining\npotential. We also discuss its possible relevance for vortex nucleation in\nrotating traps.", "By combining high-resolution HST and wide-field ground based observations, in\nultraviolet and optical bands, we study the Blue Stragglers Star (BSS)\npopulation of the galactic globular cluster M5 (NGC 5904) from its very central\nregions up to its periphery. The BSS distribution is highly peaked in the\ncluster center, decreases at intermediate radii and rises again outward. Such a\nbimodal distribution is similar to those previously observed in other globular\nclusters (M3, 47Tucanae, NGC6752). As for these clusters, dynamical simulations\nsuggest that, while the majority of BSS in M5 could be originated by stellar\ncollisions, a significant fraction (20-40%) of BSS generated by mass transfer\nprocesses in primordial binaries is required to reproduce the observed radial\ndistribution. A candidate BSS has been detected beyond the cluster tidal\nradius. If confirmed, this could represent an interesting case of an\n\"evaporating\" BSS.", "This paper has been withdrawn by the authors.", "We study the influence of weak periodic signals on the transport properties\nof underdamped ratchets. We find that the constant current intervals related to\nthe ratchet, can be significantly enlarged by a weak subharmonic signal which\nis in phase with the internal driver. This stabilization phenomenon is found to\nexist both in absence and in presence of noise. The dependence of this effect\non the phase of the applied signal is also investigated.", "We consider the Brownian motion of a quantum mechanical particle in a\none-dimensional parabolic potential with periodically modulated curvature under\nthe influence of a thermal heat bath. Analytic expressions for the\ntime-dependent position and momentum variances are compared with results of an\niterative algorithm, the so-called quasiadiabatic propagator path integral\nalgorithm (QUAPI). We obtain good agreement over an extended range of\nparameters for this spatially continuous quantum system. These findings\nindicate the reliability of the algorithm also in cases for which analytic\nresults may not be available a priori.", "We investigate the macroscopic quantum tunneling of the attractive\nBose-Einstein condensate. Within the effective Lagrangian framework, we find\nbounce solutions and explicitly calculate the decay rate of the condensate\ntrapped in a cylindrically symmetric potential. In particular, in the case\nwhere the number of condensed bosons is slightly below a certain critical\nnumber, we present a detailed analysis of the bounce solutions and discuss the\napproximations employed in our calculations. The effects of finite temperatures\nand the shape of the trapping potential are evaluated.", "We present a detailed discussion of the crossover from mean-field to Ising\ncritical behavior upon approach of the critical point, both for He3 and Xe. By\ncombining different sets of experimental data, we are able to cover an\nunusually large temperature range on either side of the critical temperature\nT_c. Below T_c, we thus can make an accurate comparison with a recent\ncalculation for the crossover of the coexistence curve. For the regime above\nT_c, an analysis of the compressibility demonstrates that the crossover regime\nin He3 is unexpectedly widened by a subtle interplay between quantum and\ncritical fluctuations.", "(Abridged) I report new light curves and determine the rotations and phase\nfunctions of several large Kuiper Belt objects, including the dwarf planet Eris\n(2003 UB313). (120348) 2004 TY364 shows a light curve which if double-peaked\nhas a period of 11.70+-0.01 hours and peak-to-peak amplitude of 0.22+-0.02\nmagnitudes. (84922) 2003 VS2 has a well defined double-peaked light curve of\n7.41+-0.02 hours with a 0.21+-0.02 magnitude range. (126154) 2001 YH140 shows\nvariability of 0.21+-0.04 magnitudes with a possible 13.25+-0.2 hour\nsingle-peaked period. The seven new KBOs in the sample which show no\ndiscernible variations within the uncertainties on short rotational time scales\nare 2001 UQ18, (55565) 2002 AW197, (119979) 2002 WC19, (120132) 2003 FY128,\n(136108) Eris 2003 UB313, (90482) Orcus 2004 DW, and (90568) 2004 GV9. The\nthree medium to large sized Kuiper Belt objects 2004 TY364, Orcus and 2004 GV9\nshow fairly steep linear phase curves (~0.18 to 0.26 mags per degree) between\nphase angles of 0.1 and 1.5 degrees. The extremely large dwarf planet Eris\n(2003 UB313) shows a shallower phase curve (0.09+-0.03 mags per degree) which\nis more similar to the other known dwarf planet Pluto. It appears the surface\nproperties of the largest dwarf planets in the Kuiper Belt maybe different than\nthe smaller Kuiper Belt objects. This may have to do with the larger objects\nability to hold more volatile ices as well as sustain atmospheres. The absolute\nmagnitudes obtained using the measured phase slopes are a few tenths of\nmagnitudes different from those given by the MPC.", "High-field antiferromagnetic-resonance (AFMR) spectra were obtained in the\nfrequency range 60 GHz < \\nu < 700 GHz and for magnetic fields up to 8 T in\ntwin-free single crystals of La_{0.95}Sr_{0.05}MnO_3. At low temperatures two\nantiferromagnetic modes were detected, which reveal different excitation\nconditions and magnetic field dependencies. No splitting of these modes was\nobserved for any orientation of the static magnetic field excluding the\nphase-separation scenario for this composition. Instead, the full data set\nincluding the anisotropic magnetization can be well described using a\ntwo-sublattice model of a canted antiferromagnetic structure.", "Spectral variability is the main tool for constraining emission models of BL\n  Lac objects. By means of systematic observations of the BL Lac prototype PKS\n2155-304 in the infrared-optical band, we explore variability on the scales of\nmonths, days and hours. We made our observations with the robotic 60 cm\ntelescope REM located at La Silla, Chile. VRIJHK filters were used. PKS\n2155-304 was observed from May to December 2005. The wavelength interval\nexplored, the total number of photometric points and the short integration time\nrender our photometry substantially superior to previous ones for this source.\nOn the basis of the intensity and colour we distinguish three different states\nof the source, each of duration of months, which include all those described in\nthe literature. In particular, we report the highest state ever detected in the\nH band. The source varied by a factor of 4 in this band, much more than in the\nV band (a factor ~2). The source softened with increasing intensity, contrary\nto the general pattern observed in the UV-X-ray bands. On five nights of\nNovember we had nearly continuous monitoring for 2-3 hours. A variability\nepisode with a time scale of ~24 h is well documented, a much more rapid flare\nwith t=1-2 h, is also apparent, but is supported by relatively few points.", "We generalize the Barab\\'{a}si--Albert's model of growing networks accounting\nfor initial properties of sites and find exactly the distribution of\nconnectivities of the network $P(q)$ and the averaged connectivity\n$\\bar{q}(s,t)$ of a site $s$ in the instant $t$ (one site is added per unit of\ntime). At long times $P(q) \\sim q^{-\\gamma}$ at $q \\to \\infty$ and\n$\\bar{q}(s,t) \\sim (s/t)^{-\\beta}$ at $s/t \\to 0$, where the exponent $\\gamma$\nvaries from 2 to $\\infty$ depending on the initial attractiveness of sites. We\nshow that the relation $\\beta(\\gamma-1)=1$ between the exponents is universal.", "We have shown that the lattice-gas model with four repulsive pair interaction\nconstants (corresponding to the four nearest coordination shells) on a simple\ncubic lattice is a sufficient model to describe the main types of cation\nordering in relaxors. The phase diagram, obtained by the cluster variation\nmethod, shows the sequences of transitions between the phases 1:2 - 1:1 -\ndisordered and 1:2 - disordered.", "We present evidence for the formation of dust grains in an unusual Type Ib SN\nbased on late-time spectra of SN 2006jc. The progenitor suffered an LBV-like\noutburst just 2 yr earlier, and we propose that the dust formation is a\nconsequence of the SN blast wave overtaking that LBV-like shell. The key\nevidence for dust formation is (a) the appearance of a red/near-IR continuum\nsource fit by 1600 K graphite grains, and (b) fading of the redshifted sides of\nHe I emission lines, yielding progressively more asymmetric blueshifted lines\nas dust obscures receding material. This provides the strongest case yet for\ndust formation in any SN Ib/c. Both developments occurred between 51 and 75 d\nafter peak, while other SNe observed to form dust did so after a few hundred\ndays. Geometric considerations indicate that dust formed in the dense swept-up\nshell between the forward and reverse shocks, and not in the freely expanding\nSN ejecta. Rapid cooling leading to dust formation may have been aided by\nextremely high shell densities, as indicated by He I line ratios. The brief\nepoch of dust formation is accompanied by He II 4686 emission and enhanced\nX-ray emission. These clues suggest that the unusual dust formation in this\nobject was not due to properties of the SN itself, but instead -- like most\npeculiarities of SN 2006jc -- was a consequence of the dense environment\ncreated by an LBV-like eruption 2 yr before the SN.", "We characterize the molecular environment of candidate massive young stellar\nobjects (MYSOs) signposted by methanol masers. Single pixel observations of 10\ntransitions of HCO^+, CO and CS isotopomers were carried out, using the IRAM\n30m telescope. We studied a sample of 28 targets for which the 6.7GHz maser\nemission positions are known with a sub-arcsecond accuracy. The systemic\nvelocity inferred from the optically thin lines agrees within 3km/s with the\ncentral velocity of the maser emission for most of the sources. About 64% of\nthe sources show line wings in one or more transitions of CO, HCO^+ and CS\nspecies, indicating the presence of molecular outflows. Comparison of the\nwidths of line wings and methanol maser emission suggests that the 6.7GHz maser\nline traces the environment of MYSO of various kinematic regimes. Therefore\nconditions conducive for the methanol maser can exist in the inner parts of\nmolecular clouds or circumstellar discs as well as in the outer parts\nassociated with molecular outflows. Calculations of the physical conditions\nbased on the CO and HCO^+ lines and the CS line intensity ratios refine the\ninput parameters for maser models.", "We report CCD photometry and spectroscopy during 2006 outburst of the dwarf\nnova SDSS J102146.44+234926.3 (SDSS J1021). The photographic plates from the\nMAO, SAI and CrAO plate archives, which cover the position of the SDSS J1021,\nwere inspected for the presence of previous outbursts. We also present the\nBVRcIc photometric calibration of 52 stars in SDSS J1021 vicinity, which have\nV-magnitude in the range of 11.21-17.23m and can serve as comparison stars. The\nlarge amplitude of the SDSS J1021 outburst of 7m, superhumps with a period\nbelow the ''period gap'', rebrightening during the declining stage of\nsuperoutburst, rarity of outbursts and obtained spectrum allow to classify this\nobject as a WZ Sge type dwarf nova.", "Using a widely used stellar population synthesis model, we study the ability\nof using pairs of AB system colours to break the well-known stellar\nage--metallicity degeneracy and give constraints on the two stellar-population\nparameters (age and metallicity). The relative age and metallicity\nsensitivities of AB system colours that relate to u, B, g, V, r, R, i, I, z, J,\nH, and K bands are presented, and the abilities of various colour pairs for\nbreaking the age--metallicity degeneracy are quantified by an uncertainty\nparameter (UP) method. Our results suggest that a few pairs of colours can be\nused to constrain the two above stellar-population parameters. This will be\nvery useful for exploring the stellar populations of distant galaxies. In\ndetail, colour pairs [(r-K), (u-R)] and [(r-K), (u-r)] are shown to be the best\npairs for estimating stellar ages and metallicities. They can constrain two\nstellar-population parameters on average with age uncertainties less than 3.89\nGyr and metallicity uncertainties less than 0.34 dex for typical uncertainties\nin colours. Some other colour pairs, such as [(R-K), (u-R)], [(I-K), (u-R)],\n[(R-K), (u-r)] and [(i-J), (u-R)], can possibly be used for constraining the\ntwo parameters, too. As a whole, our results suggest that colours relating to\nboth UBVRIJHK and ugriz magnitudes are much better than either UBVRIJHK colours\nor ugriz colours for breaking the well-known degeneracy. The results also show\nthat the stellar ages and metallicities of galaxies observed by the Sloan\nDigital Sky Survey (SDSS) and the Two-Micron All-Sky Survey (2MASS) can be\nestimated via photometry data. It is also shown that the colours can be used in\nconjunction with line indices to measure stellar-population parameters.", "We present follow-up observations of pulsating subdwarf B (sdB) stars as part\nof our efforts to resolve the pulsation spectra for use in asteroseismological\nanalyses. This paper reports on multisite campaigns of the pulsating sdB stars\nPG 1618+563B and PG 0048+091. Data were obtained from observatories placed\naround the globe for coverage from all longitudes. For PG 1618+563B, our\nfive-site campaign uncovered a dichotomy of pulsation states: Early during the\ncampaign the amplitudes and phases (and perhaps frequencies) were quite\nvariable while data obtained late in the campaign were able to fully resolve\nfive stable pulsation frequencies. For PG 0048+091, our five-site campaign\nuncovered a plethora of frequencies with short pulsation lifetimes. We find\nthem to have observed properties consistent with stochastically excited\noscillations, an unexpected result for subdwarf B stars. We discuss our\nfindings and their impact on subdwarf B asteroseismology.", "The dielectric constant of a conductor-insulator mixture shows a pronounced\nmaximum above the critical volume concentration. Further experimental evidence\nis presented as well as a theoretical consideration based on a phenomenological\nequation. Explicit expressions are given for the position of the maximum in\nterms of scaling parameters and the (complex) conductances of the conductor and\ninsulator. In order to fit some of the data, a volume fraction dependent\nexpression for the conductivity of the more highly conductive component is\nintroduced.", "We show here that the regularization of the conductivity resulting from the\nbosonic interactions on the `insulating' (quantum disordered) side of an\ninsulator-superconductor transition in 2D gives rise to a metal with a finite\nconductivity, $\\sigma =(2/\\pi) 4 e^2/h$, as temperature tends to zero. The Bose\nmetal is stable to weak disorder and hence represents a concrete example of an\ninteraction-induced metallic phase. Phenomenological inclusion of dissipation\nreinstates the anticipated insulating behaviour in the quantum-disordered\nregime. Hence, we conclude that the traditionally-studied\ninsulator-superconductor transition, which is driven solely by quantum\nfluctuations, corresponds to a superconductor-metal transition. The possible\nrelationship to experiments on superconducting thin films in which a\nlow-temperature metallic phase has been observed is discussed.", "Several recent experimental studies have confirmed the possibility of\nswitching the magnetization direction in the small magnetic domains by pumping\nlarge spin-polarized currents through them. On the basis of equations proposed\nby J.Slonczewski for the case when magnetization of the domains is almost\nuniform, we analyze the stability and switching for two types of magnetic and\nshape anisotropies of a magnetic domain in a nanowire and find qualitatively\ndifferent behavior, including different shapes of bistable regions. Our study\nis analytic as opposed to recent numeric work. Assumed anisotropies can be\nrealized in experiments and our predictions can be used to experimentally test\nthe theory of spin-transfer torques. Such test would be especially interesting\nsince alternative approaches are discussed in the literature.", "Reaction-diffusion problems are often described at a macroscopic scale by\npartial derivative equations of the type of the Fisher or\nKolmogorov-Petrovsky-Piscounov equation. These equations have a continuous\nfamily of front solutions, each of them corresponding to a different velocity\nof the front. By simulating systems of size up to N=10^(16) particles at the\nmicroscopic scale, where particles react and diffuse according to some\nstochastic rules, we show that a single velocity is selected for the front.\nThis velocity converges logarithmically to the solution of the F-KPP equation\nwith minimal velocity when the number N of particles increases. A simple\ncalculation of the effect introduced by the cutoff due to the microscopic scale\nallows one to understand the origin of the logarithmic correction.", "We derive an explicit relationship between the moment of inertia and the\nquadrupole response function of an interacting gas confined in a harmonic trap.\nThe relationship holds for both Bose and Fermi systems and is well suited to\nreveal the effects of irrotationality of the superfluid motion. Recent\nexperimental results on the scissors mode are used to extract the value of the\nmoment of inertia of a trapped Bose gas and to point out the deviations from\nthe rigid value due to superfluidity.", "Recent X-ray surveys have provided a large number of high-luminosity,\nobscured Active Galactic Nuclei (AGN), the so-called Type 2 quasars. Despite\nthe large amount of multi-wavelength supporting data, the main parameters\nrelated to the black holes harbored in such AGN are still poorly known. Here we\npresent the results obtained for a sample of eight Type 2 quasars in the\nredshift range 0.9-2.1 selected from the HELLAS2XMM survey, for which we used\nKs-band, Spitzer IRAC and MIPS data at 24 micron to estimate bolometric\ncorrections, black hole masses, and Eddington ratios.", "A restricted dynamics, previously introduced in a kinetic model for\nrelaxation phenomena in linear polymer chains, is used to study the dynamic\ncritical exponent of one-dimensional Ising models. Both the alternating\nisotopic chain and the alternating-bond chain are considered. In contrast with\nwhat occurs for the Glauber dynamics, in these two models the dynamic critical\nexponent turns out to be the same. The alternating isotopic chain with the\nrestricted dynamics is shown to lead to Nagel scaling for temperatures above\nsome critical value. Further support is given relating the Nagel scaling to the\nexistence of multiple (simultaneous) relaxation processes, the dynamics\napparently not playing the most important role in determining such scaling.", "Aims and Methods: We present the results of VLBI observations of nineteen\nGHz-Peaked-Spectrum (GPS) radio sources at 1.6 GHz. Of them, 15 sources are\nselected from the Parkes Half Jansky (PHJ) sample (Snellen 2002), 4 others are\nfrom our previous observation list. We aimed at imaging the structure of GPS\nsources, searching for Compact Symmetric Objects (CSOs) and studying the\nabsorption for the convex radio spectra of GPS sources.\n  Results: We obtained total intensity 1.6 GHz VLBI images of 17 sources for\nthe first time. Of them, 80% show mini-double-lobe radio structure, indicating\nthat they are CSOs or candidates, and their host AGNs could be edge-on to us.\nThis result suggests that there is a high incidence of mini double-lobe sources\n(or CSOs) in the PHJ sample. The sources J0323+0534, J1135-0021, J1352+0232,\nJ2058+0540, J2123-0112 and J2325-0344 with measured redshift, showing\ndouble-lobe structure with sizes of <1 kpc, are classified as CSOs. Three\nsources J1057+0012, J1600-0037 and J1753+2750 are considered as core-jet\nsources according to their morphologies and flux variability.", "Based on our sample of 10095 galaxies with bulge-disc decompositions we\nderive the empirical B-band internal attenuation--inclination relation for\ngalaxy discs and their associated central bulges. Our results agree well with\nthe independently derived dust models of Tuffs et al., leading to a direct\nconstraint on the mean opacity of spiral discs of Tau_B^f = 3.8 +/- 0.7\n(central face-on B-band opacity). Depending on inclination, the B-band\nattenuation correction varies from 0.2 -- 1.1 mag for discs and from 0.8 -- 2.6\nmag for bulges. We find that, overall, 37 per cent of all B-band photons\nproduced in discs in the nearby universe are absorbed by dust, a figure that\nrises to 71 per cent for bulge photons. The severity of internal dust\nextinction is such that one must incorporate internal dust corrections in all\noptical studies of large galaxy samples. This is particularly pertinent for\noptical HST comparative evolutionary studies as the dust properties will also\nbe evolving. We use the new results to revise our recent estimates of the\nspheroid and disc luminosity functions. From our best fitting dust models we\nderive a redshift zero cosmic dust density of rho_{dust} ~ (5.3 +/- 1.7) x\n10^5, h M_{odot} Mpc^-3. This implies that (0.0083 +/- 0.0027), h per cent of\nthe baryons in the Universe are in the form of dust and (11.9 +/- 1.7), h per\ncent (Salpeter-`lite' IMF) are in the form of stars (~58 per cent reside in\ngalaxy discs, ~10 per cent in red elliptical galaxies, ~29 per cent in\nclassical galaxy bulges and the remainder in low luminosity blue spheroid\nsystems/components). [Abridged]", "Our recent studies on Co-clusters embedded in various matrices reveal that\nthe co-deposition technique (simultaneous deposition of two beams : one for the\npre-formed clusters and one for the matrix atoms) is a powerful tool to prepare\nmagnetic nanostructures with any couple of materials even though they are\nmiscible. We study, both sharply related, structure and magnetism of the Co/Nb\nsystem. Because such a heterogeneous system needs to be described at different\nscales, we used microscopic and macroscopic techniques but also local selective\nabsorption ones. We conclude that our clusters are 3 nm diameter f.c.c\ntruncated octahedrons with a pure cobalt core and a solid solution between Co\nand Nb located at the interface which could be responsible for the magnetically\ninactive monolayers we found. The use of a very diluted Co/Nb film, further\nlithographed, would allow us to achieve a pattern of microsquid devices in view\nto study the magnetic dynamics of a single-Co cluster.", "Following deep astrometric and photometric study of the cluster NGC2682\n(M67), we are able to accurately determine its fundamental parameters. Being an\nold and rich cluster, M67 is a relevant object for the analysis of the Galactic\ndisk evolution. M67 is well studied but the lack of a wide and deep Stromgren\nphotometric study makes our results worthwhile. The brightest stars of the open\ncluster M67 were used as uvby-Hbeta standard stars in our studies of NGC1817\nand NGC2548, and the extension of the field covered, as well as the amount of\nobservations, allowed to obtain the best set of Stromgren data ever published\nfor this cluster. We discuss the results of our CCD uvby-Hbeta\nintermediate-band photometry, covering an area of about 50'x50' down to V 19.\nMoreover, a complete membership segregation based on astrometric and\nphotometric criteria is obtained. The photometric analysis of a selected sample\nof stars yields a reddening value of E(b-y)= 0.03\\pm0.03, a distance modulus of\nV_0-M_V= 9.7\\pm0.2 and [Fe/H]= 0.01\\pm0.14. Through isochrone fitting we found\nan age of log t= 9.6\\pm0.1 (4.2\\pm0.2 Gyr). A clump of approximately 60 stars\naround V= 16, (b-y)= 0.4 could be interpreted as a population of\npre-cataclysmic variable stars (if members), or as a stream of field G-type\nstars placed at twice the distance of the cluster (if non-members).", "The past three decades of investigation on nuclear physics and pulsar\nastrophysics have seen gradual recognition that elastodynamic approach to the\ncontinuum mechanics of nuclear matter provides proper account of macroscopic\nmotions of degenerate Fermi-matter constituting interior of the nuclear\nmaterial objects, the densest of all known today. This paper focuses on one\ntheoretical issue of this development which is concerned with oscillatory\nbehavior of a viscoelastic solid globe in the regime of quasistatic,\nforce-free, non-compressional oscillations less investigated in the literature\ncompared to oscillations in the regime of standing shear waves. We show that in\nthis case the problem of computing frequency and lifetime of spheroidal and\ntorsional modes of non-radial shear vibrations damped by viscosity can be\nunambiguously resolved by working from the energy balance equation and taking\nadvantage of the Rayleigh's variational method. The efficiency of this method\nis demonstrated by solid globe models of nuclear physics and pulsar\nastrophysics dealing with oscillations of a spherical mass of a viscoelastic\nFermi-solid with homogeneous and non-homogeneous profiles of the bulk density,\nthe shear modulus, and the shear viscosity.", "Here we report the first inelastic neutron scattering study of the magnetic\nexcitations in the incommensurate phase of a spin-Peierls material. The results\non CuGeO3 provide direct evidence of a finite excitation gap, two sharp\nmagnetic excitation branches and a very low-lying excitation which is\nidentified as a phason mode, the Goldstone mode of the incommensurate soliton\nlattice.", "The past two Decadal Surveys in Astronomy and Astrophysics recommended the\ncompletion of a space-based interferometry mission, known today as SIM\nPlanetQuest, for its unique ability to detect and characterize nearby rocky\nplanets (Bahcall 1991, McKee & Taylor 2001), as well as contributions to a\nbroad range of problems in astrophysics. Numerous committees of the National\nResearch Council as well as NASA Roadmaps have similarly highlighted SIM as the\none technology that offers detection and characterization of rocky planets\naround nearby stars and which is technically ready. To date, SIM remains the\nonly program with the capability of detecting and confirming rocky planets in\nthe habitable zones of nearby solar-type stars. Moreover, SIM measures masses\nand three-dimensional orbits of habitable planets around nearby stars (within\n25 pc); these are the only stars for which follow-up by other techniques is\nfeasible, such as space-based spectroscopy, ground-based interferometry, and of\ncourse TPF.", "An effective intra- and inter-ladder charge-spin hamiltonian for the\nquarter-filled ladder compound $\\alpha'$-NaV$_2$O$_5$ has been derived by using\nthe standard canonical transformation method. In the derivation, it is clear\nthat a finite inter-site Coulomb repulsion is needed to get a meaningful result\notherwise the perturbation becomes ill-defined. Various limiting cases\ndepending on the values of the model parameters have been analyzed in detail\nand the effective exchange couplings are estimated. We find that the effective\nintra-ladder exchange may become ferromagnetic for the case of zig-zag charge\nordering in a purely electronic model.\n  We estimate the magnitude of the effective inter-rung Coulomb repulsion in a\nladder and find it to be about one-order of magnitude too small in order to\nstabilize charge-ordering.", "We have studied structural, magnetic and transport properties as a function\nof temperature and magnetic field in the electron doped manganite YxCa1-xMnO3,\nfor 0<x<0.25. We found that in the paramagnetic regime, the magnetic\nsusceptibility, \\chi, deviates substantially from a Curie-Weiss law for x>0.\nWith a simple model where antiferromagnetic (AF) superexchange and\nferromagnetic (FM) double exchange (DE) compete, we fit the experimental\n\\chi(x, T) obtaining parameter values which indicate that the FM-DE interaction\nis about twice as intense as the AF interaction. In the ordered phase, the\nH-dependence of the magnetization M(x,T) is explained in terms of magnetic\npolarons. We propose that the displacement of the eg electrons (in the G-type\nAF background) causes the alignement of the polaron with H. Signatures of\npolaronic behavior were also found in the x and T dependence of the electric\nresistivity.", "We present the results of a search for ultra-compact dwarf galaxies (UCDs) in\nsix different galaxy groups: Dorado, NGC1400, NGC0681, NGC4038, NGC4697 and\nNGC5084. We searched in the apparent magnitude range 17.5 < b_j < 20.5 (except\nNGC5084: 19.2 < b_j < 21.0). We found 1 definite plus 2 possible UCD candidates\nin the Dorado group and 2 possible UCD candidates in the NGC1400 group. No UCDs\nwere found in the other groups. We compared these results with predicted\nluminosities of UCDs in the groups according to the hypothesis that UCDs are\nglobular clusters formed in galaxies. The theoretical predictions broadly agree\nwith the observational results, but deeper surveys are needed to fully test the\npredictions.", "We study the ground-state spin correlations in the gapless incommensurate\nregime of a S=1/2 XXZ chain and a two-leg antiferromagnetic ladder under a\nmagnetic field, in which the gapless excitations form a Tomonaga-Luttinger (TL)\nliquid. We calculate numerically the two-spin correlation functions and the\nlocal magnetization in the two models using the density-matrix\nrenormalization-group method. By fitting the numerical results for an open XXZ\nchain of 100 spins to correlation functions of a Gaussian model, we determine\nthe TL-liquid parameter K and the amplitudes of the correlation functions. The\nvalue of K estimated from the fits is in excellent agreement with the exact\nvalue obtained from the Bethe ansatz. We apply the same method to the open\nladder consisting of 200 spins and determine the dependence of K on the\nmagnetization M. The K-M relation changes drastically depending on the ratio of\nthe coupling constants in the leg and rung directions. We also discuss\nimplications of these results to experiments on the nuclear spin relaxation\nrate 1/T_1 and dynamical spin structure factors.", "The intrinsic distribution of spectral indices in GeV energies of\ngamma-ray--loud blazars is a critical input in determining the spectral shape\nof the unresolved blazar contribution to the diffuse extragalactic gamma-ray\nbackground, as well as an important test of blazar emission theories. We\npresent a maximum-likelihood method of determining the intrinsic spectral index\ndistribution (ISID) of a population of gamma-ray emitters which accounts for\nerror in measurement of individual spectral indices, and we apply it to EGRET\nblazars. We find that the most likely Gaussian ISID for EGRET blazars has a\nmean of 2.27 and a standard deviation of 0.20. We additionally find some\nindication that FSRQs and BL Lacs may have different ISIDs (with BL Lacs being\nharder). We also test for spectral index hardening associated with blazar\nvariability for which we find no evidence. Finally, we produce simulated GLAST\nspectral index datasets and perform the same analyses. With improved statistics\ndue to the much larger number of resolvable blazars, GLAST data will help us\ndetermine the ISIDs with much improved accuracy. Should any difference exist\nbetween the ISIDs of BL Lacs and FSRQs or between the ISIDs of blazars in the\nquiescent and flaring states, GLAST data will be adequate to separate these\nISIDs at a significance better than 3 sigma.", "We have imaged a $\\sim$6 arcminute$^2$ region in the Bo\\\"otes Deep Field\nusing the 350 $\\mu$m-optimised second generation Submillimeter High Angular\nResolution Camera (SHARC II), achieving a peak 1$\\sigma$ sensitivity of $\\sim$5\nmJy. We detect three sources above 3$\\sigma$, and determine a spurious source\ndetection rate of 1.09 in our maps. In the absence of $5\\sigma$ detections, we\nrely on deep 24 $\\mu$m and 20 cm imaging to deduce which sources are most\nlikely to be genuine, giving two real sources. From this we derive an integral\nsource count of 0.84$^{+1.39}_{-0.61}$ sources arcmin$^{-2}$ at $S>13$ mJy,\nwhich is consistent with 350 $\\mu$m source count models that have an\nIR-luminous galaxy population evolving with redshift. We use these constraints\nto consider the future for ground-based short-submillimetre surveys.", "Van Marle et al. (2005) showed that circumstellar absorption lines in early\nType Ib/c supernova and gamma-ray burst afterglow spectra may reveal the\nprogenitor evolution of the exploding Wolf-Rayet star. While the quoted paper\ndeals with Wolf-Rayet stars which evolved through a red supergiant stage, we\ninvestigate here the initially more massive Wolf-Rayet stars which are thought\nto evolve through a Luminous Blue Variable (LBV) stage. We perform hydrodynamic\nsimulations of the evolution of the circumstellar medium around a 60 Msol star,\nfrom the main sequence through the LBV and Wolf-Rayet stages, up to core\ncollapse. We then compute the column density of the circumstellar matter as a\nfunction of radial velocity, time and angle. This allows a comparison with the\nnumber and blue-shifts, of absorption components in the spectra of LBVs,\nWolf-Rayet stars, Type Ib/c supernovae and gamma-ray burst afterglows. Our\nsimulation for the post-LBV stage shows the formation of various absorption\ncomponents, which are, however, rather short lived; they dissipate on time\nscales shorter than 50,000yr. As the LBV stage is thought to occur at the\nbeginning of core helium burning, the remaining Wolf-Rayet life time is\nexpected to be one order of magnitude larger. When interpreting the absorption\ncomponents in the afterglow spectrum of GRB-021004 as circumstellar, it can be\nconcluded that the progenitor of this source did most likely not evolve through\nan LBV stage. However, a close binary with late common-envelope phase (Case C)\nmay produce a circumstellar medium that closely resembles the LBV to Wolf-Rayet\nevolution, but with a much shorter Wolf-Rayet period.", "We investigate the evolution of binary fractions in star clusters using\nN-body models of up to 100000 stars. Primordial binary frequencies in these\nmodels range from 5% to 50%. Simulations are performed with the NBODY4 code and\ninclude a full mass spectrum of stars, stellar evolution, binary evolution and\nthe tidal field of the Galaxy. We find that the overall binary fraction of a\ncluster almost always remains close to the primordial value, except at late\ntimes when a cluster is near dissolution. A critical exception occurs in the\ncentral regions where we observe a marked increase in binary fraction with time\n-- a simulation starting with 100000 stars and 5% binaries reached a core\nbinary frequency as high as 40% at the end of the core-collapse phase\n(occurring at 16 Gyr with ~20000 stars remaining). Binaries are destroyed in\nthe core by a variety of processes as a cluster evolves, but the combination of\nmass-segregation and creation of new binaries in exchange interactions produces\nthe observed increase in relative number. We also find that binaries are cycled\ninto and out of cluster cores in a manner that is analogous to convection in\nstars. For models of 100000 stars we show that the evolution of the core-radius\nup to the end of the initial phase of core-collapse is not affected by the\nexact value of the primordial binary frequency (for frequencies of 10% or\nless). We discuss the ramifications of our results for the likely primordial\nbinary content of globular clusters.", "We derive solutions for the twin wall linking two tetragonal variants of the\ncubic-tetragonal ferroelastic transformation, including for the first time the\ndilatational and shear energies and strains. Our solutions satisfy the\ncompatibility relations exactly and are obtained at all temperatures. They\nrequire four non-vanishing strains except at the Barsch-Krumhansl temperature\nTBK (where only the two deviatoric strains are needed). Between the critical\ntemperature and TBK, material in the wall region is dilated, while below TBK it\nis compressed. In agreement with experiment and more general theory, the twin\nwall lies in a cubic 110-type plane. We obtain the wall energy numerically as a\nfunction of temperature and we derive a simple estimate which agrees well with\nthese values.", "We study analytically and numerically the problem of two particles with a\nlong range attractive interaction on a two-dimensional (2d) lattice with\ndisorder. It is shown that below some critical disorder the interaction creates\ndelocalized coupled states near the Fermi level. These states appear inside\nwell localized noninteracting phase and have a form of two-particle ring which\ndiffusively propagates over the lattice.", "We combine the Density Matrix Technique (DMRG) with Green Function Monte\nCarlo (GFMC) simulations. The DMRG is most successful in 1-dimensional systems\nand can only be extended to 2-dimensional systems for strips of limited width.\nGFMC is not restricted to low dimensions but is limited by the efficiency of\nthe sampling. This limitation is crucial when the system exhibits a so-called\nsign problem, which on the other hand is not a particular obstacle for the\nDMRG. We show how to combine the virtues of both methods by using a DMRG\nwavefunction as guiding wave function for the GFMC. This requires a special\nrepresentation of the DMRG wavefunction to make the simulations possible within\nreasonable computational time. As a test case we apply the method to the\n2-dimensional frustrated Heisenberg antiferromagnet. By supplementing the\nbranching in GFMC with Stochastic Reconfiguration (SR) we get a stable\nsimulation with a small variance also in the region where the fluctuations due\nto minus sign problem are maximal. The sensitivity of the results to the choice\nof the guiding wavefunction is extensively investigated. We analyse the model\nas a function of the ratio of the next-nearest to nearest neighbor coupling\nstrength. We observe in the frustrated regime a pattern of the spin\ncorrelations which is in-between dimerlike and plaquette type ordering, states\nthat have recently been suggested. It is a state with strong dimerization in\none direction and weaker dimerization in the perpendicular direction.", "The light curves produced by all-sky monitors, such as the Rossi X-ray Timing\nExplorer All-Sky Monitor and the Swift Burst Alert Telescope (BAT), generally\nhave non-uniform error bars. In searching for periodic modulation in this type\nof data using power spectra it can be important to use appropriate weighting of\ndata points to achieve the best sensitivity. It was recently demonstrated that\nfor Swift BAT data a simple weighting scheme can actually sometimes reduce the\nsensitivity of the power spectrum depending on source brightness. Instead, a\nmodified weighting scheme, based on the Cochran semi-weighted mean, gives\nimproved results independent of source brightness. We investigate the benefits\nof weighting power spectra in period searches using simulated GLAST LAT\nobservations of gamma-ray binaries.", "In the context of measuring structure and morphology of intermediate redshift\ngalaxies with recent HST/ACS surveys, we tune, test, and compare two widely\nused fitting codes (GALFIT and GIM2D) for fitting single-component Sersic\nmodels to the light profiles of both simulated and real galaxy data. We find\nthat fitting accuracy depends sensitively on galaxy profile shape. Exponential\ndisks are well fit with Sersic models and have small measurement errors,\nwhereas fits to de Vaucouleurs profiles show larger uncertainties owing to the\nlarge amount of light at large radii. We find that both codes provide reliable\nfits and little systematic error, when the effective surface brightness is\nabove that of the sky. Moreover, both codes return errors that significantly\nunderestimate the true fitting uncertainties, which are best estimated with\nsimulations. We find that GIM2D suffers significant systematic errors for\nspheroids with close companions owing to the difficulty of effectively masking\nout neighboring galaxy light; there appears to be no work around to this\nimportant systematic in GIM2D's current implementation. While this crowding\nerror affects only a small fraction of galaxies in GEMS, it must be accounted\nfor in the analysis of deeper cosmological images or of more crowded fields\nwith GIM2D. In contrast, GALFIT results are robust to the presence of neighbors\nbecause it can simultaneously fit the profiles of multiple companions thereby\ndeblending their effect on the fit to the galaxy of interest. We find GALFIT's\nrobustness to nearby companions and factor of >~20 faster runtime speed are\nimportant advantages over GIM2D for analyzing large HST/ACS datasets. Finally\nwe include our final catalog of fit results for all 41,495 objects detected in\nGEMS.", "The high multiplicity of massive stars in dense, young clusters is\nestablished early in their evolution. The mechanism behind this remains\nunresolved. Recent results suggest that massive protostars may capture\ncompanions through disk interactions with much higher efficiency than their\nsolar mass counterparts. However, this conclusion is based on analytic\ndeterminations of capture rates and estimates of the robustness of the\nresulting binaries. We present the results of coupled n-body and SPH\nsimulations of star-disk encounters to further test the idea that disk-captured\nbinaries contribute to the observed multiplicity of massive stars.", "We present an {\\it ab initio} analysis of electron conduction through a\n$C_{60}$ molecular device. Charge transfer from the device electrodes to the\nmolecular region is found to play a crucial role in aligning the lowest\nunoccupied molecular orbital (LUMO) of the $C_{60}$ to the Fermi level of the\nelectrodes. This alignment induces a substantial device conductance of $\\sim\n2.2 \\times (2e^2/h)$. A gate potential can inhibit charge transfer and\nintroduce a conductance gap near $E_F$, changing the current-voltage\ncharacteristics from metallic to semi-conducting, thereby producing a field\neffect molecular current switch.", "We use the Newtonian limit of a general scalar-tensor theory around a\nbackground field to study astrophysical effects. The gravitational theory\nmodifies the standard Newtonian potential by adding a Yukawa term to it, which\nis quantified by two theoretical parameters: $\\lambda$, the lenghtscale of the\ngravitational interaction and its strength, $\\alpha$. Within this formalism we\nfirstly present a numerical study on the formation of bars in isolated\ngalaxies. We have found for positive $\\alpha$ that the modified gravity\ndestabilizes the galactic discs and leads to rapid bar formation in isolated\ngalaxies. Values of $\\lambda$ in the range $\\approx 8$ -- 14 kpc produce\nstrongest bars in isolated models. Then, we extent this work by considering\ntidal effects due to interacting galaxies. We send two spirals to collide and\nstudy the bar properties of the remnant. We characterize the bar kinematical\nproperties in terms of our parameters ($\\lambda, \\alpha$).", "A detailed calculation of the finite temperature dynamic structure function\nof the free Bose gas is presented and discussed. After a short derivation of\nthe expressions describing the exact response $S(q,\\omega;T)$ and the Impulse\nApproximation (IA) $S_{IA}(q,\\omega;t)$, their main properties and their\nevolution with q and T are analyzed. The lowest order energy weighted sum rules\nof both $S(q,\\omega;T)$ and $S_{IA}(q,\\omega;T)$ are also derived and\ncommented. Finally, the $q\\to\\infty$ asymptotic behavior is analyzed and\ndiscussed in terms of scaling laws.", "In many applications, transport of particles can be described by the\ndiffusion equation, or its convective-diffusion generalizations, in part of\nthree-dimensional space. In particular, in surface deposition or in growth of\naggregates or sediments, particles in the suspension outside the surface or\naggregate boundary can be considered as diffusing under the influence of\napplied forces, such as the double-layer interactions or gravity. However, the\ndiffusion equation cannot be used at the substrate or inside the aggregate. One\nconvenient and widely used approach has been to impose boundary conditions at\nthe surface, to supplement and completely define the diffusion problem outside\nit. This short survey describes some theoretical results on the use of such\nboundary conditions and their physical interpretation.", "A Landau model is used to study the phase behavior of the surface layer for\nmagnetic and cholesteric liquid crystal systems that are at or near a Lifshitz\npoint marking the boundary between modulated and homogeneous bulk phases. The\nmodel incorporates surface and bulk fields and includes a term in the free\nenergy proportional to the square of the second derivative of the order\nparameter in addition to the usual term involving the square of the first\nderivative. In the limit of vanishing bulk field, three distinct types of\nsurface ordering are possible: a wetting layer, a non-wet layer having a small\ndeviation from bulk order, and a different non-wet layer with a large deviation\nfrom bulk order which decays non-monotonically as distance from the wall\nincreases. In particular the large deviation non-wet layer is a feature of\nsystems at the Lifshitz point and also those having only homogeneous bulk\nphases.", "In this paper, we provide a simple, ``generic'' interpretation of\nmultifractal scaling laws and multiplicative cascade process paradigms in terms\nof volatility correlations. We show that in this context 1/f power spectra, as\nobserved recently by Bonanno et al., naturally emerge. We then propose a simple\nsolvable ``stochastic volatility'' model for return fluctuations. This model is\nable to reproduce most of recent empirical findings concerning financial time\nseries: no correlation between price variations, long-range volatility\ncorrelations and multifractal statistics. Moreover, its extension to a\nmultivariate context, in order to model portfolio behavior, is very natural.\nComparisons to real data and other models proposed elsewhere are provided.", "We here develop an improved way of using a rotating star as a clock, set it\nusing the Sun, and demonstrate that it keeps time well. This technique, called\ngyrochronology, permits the derivation of ages for solar- and late-type main\nsequence stars using only their rotation periods and colors. The technique is\nclarified and developed here, and used to derive ages for illustrative groups\nof nearby, late-type field stars with measured rotation periods. We first\ndemonstrate the reality of the interface sequence, the unifying feature of the\nrotational observations of cluster and field stars that makes the technique\npossible, and extends it beyond the proposal of Skumanich by specifying the\nmass dependence of rotation for these stars. We delineate which stars it cannot\ncurrently be used on. We then calibrate the age dependence using the Sun. The\nerrors are propagated to understand their dependence on color and period.\nRepresentative age errors associated with the technique are estimated at ~15%\n(plus possible systematic errors) for late-F, G, K, & early-M stars. Ages\nderived via gyrochronology for the Mt. Wilson stars are shown to be in good\nagreement with chromospheric ages for all but the bluest stars, and probably\nsuperior. Gyro ages are then calculated for each of the active main sequence\nfield stars studied by Strassmeier and collaborators where other ages are not\navailable. These are shown to be mostly younger than 1Gyr, with a median age of\n365Myr. The sample of single, late-type main sequence field stars assembled by\nPizzolato and collaborators is then assessed, and shown to have gyro ages\nranging from under 100Myr to several Gyr, and a median age of 1.2Gyr. Finally,\nwe demonstrate that the individual components of the three wide binaries\nXiBooAB, 61CygAB, & AlphaCenAB yield substantially the same gyro ages.", "By basing on observations of skeletal structures of the Sun and assuming that\nsome of them are located inside of star, and also that a filamentary (linear)\nmatter (whose a model earlier was put forward by B.U. Rodionov) is in basis of\nthese internal structures the author consider possible processes of images\nformation of these structures inside the Sun and theirs coming out into space\nand also gives an elementary estimations of its parameters, which allow: i) to\nform their images in a flux of electronic neutrinos; ii) to carry out these\nimages from within of the Sun into space; iii) to develop these images in form\nof a concomitant flux of soft x-ray, which next is recorded by telescope of\nsoft x-ray. It is supposed the processes considered here, actually, can be\naccepted as future base of neutrino astronomy with high spatial resolution.", "The in-plane optical conductivity of UPd_2Al_3 was measured at temperatures\n$2 {\\rm K}<T<300$ K in the spectral range from 1 cm^{-1} to 40 cm^{-1} (0.14\nmeV to 5 meV). As the temperature decreases below 25 K a well pronounced\npseudogap of 0.2 meV develops in the optical response. In addition we observe a\nnarrow conductivity peak at zero frequency which at 2 K is less than 1 cm^{-1}\nwide but which contains only a fraction of the delocalized carriers. The gap in\nthe electronic excitations might be an inherent feature of the heavy fermioin\nground state.", "We examine the absorption spectrum of electromagnetic radiation from\nexcitons, where an exciton in the $1s$ state absorbs a photon and makes a\ntransition to the $2p$ state. We demonstrate that the absorption spectrum\ndepends strongly on the quantum degeneracy of the exciton gas, and that it will\ngenerally manifest many-body effects. Based on our results we propose that\nabsorption of infrared radiation could resolve recent contradictory\nexperimental results on excitons in Cu$_2$O.", "We consider a Callan-Symanzik and a Wilson Renormalization Group approach to\nthe infrared problem for interacting fermions in one dimension with\nbackscattering. We compute the third order (two-loop) approximation of the beta\nfunction using both methods and compare it with the well known multiplicative\nGell-Mann Low approach. We point out a previously unnoticed qualitative\ndependence of the third order fixed point on an arbitrary dimensionless\nparameter, which strongly suggest the spurious nature of the fixed point.", "We present a survey of mid-infrared gas-phase lines toward a sample of 76\ncircumstellar disks around low mass pre-main sequence stars from the Spitzer\n\"Cores to Disks\" legacy program. We report the first detections of [Ne II] and\n[Fe I] toward classical T Tauri stars in ~20% respectively ~9% of our sources.\nThe observed [Ne II] line fluxes and upper limits are consistent with [Ne II]\nexcitation in an X-ray irradiated disk around stars with X-ray luminosities\nL_X=10^{29}-10^{31} erg s^{-1}. [Fe I] is detected at ~10^-5-10^-4 L_Sun, but\nno [S I] or [Fe II] is detected down to ~10^{-6} L_Sun. The [Fe I] detections\nindicate the presence of gas-rich disks with masses of >~0.1 M_J. No H_2 0-0\nS(0) and S(1) disk emission is detected, except for S(1) toward one source.\nThese data give upper limits on the warm (T~100-200K) gas mass of a few Jovian\nmasses, consistent with recent T Tauri disk models which include gas heating by\nstellar radiation. Compact disk emission of hot (T>~500K) gas is observed\nthrough the H_2 0-0 S(2) and/or S(3) lines toward ~8% of our sources. The line\nfluxes are, however, higher by more than an order of magnitude than those\npredicted by recent disk models, even when X-ray and excess UV radiation are\nincluded. Similarly the [Ne II]/H_2 0-0 S(2) ratios for these sources are lower\nthan predicted, consistent with the presence of an additional hot molecular gas\ncomponent not included in current disk models. Oblique shocks of stellar winds\ninteracting with the disk can explain many aspects of the hot gas emission, but\nare inconsistent with the non-detection of [S I] and [Fe II] lines.", "The Ge spectrometer of the RHESSI satellite is sensitive to Gamma Ray Bursts\n(GRBs) from about 40 keV up to 17 MeV, thus ideally complementing the Swift/BAT\ninstrument whose sensitivity decreases above 150 keV. We present preliminary\nresults of spectral fits of RHESSI GRB data. After describing our method, the\nRHESSI results are discussed and compared with Swift and Konus.", "We present VLA and PdBI subarcsecond images (0.15\"-0.6\") of the\nradiocontinuum emission at 7 mm and of the SO2 J=19_{2,18}-18_{3,15} and\nJ=27_{8,20}-28_{7,21} lines toward the Cepheus A HW2 region. The SO2 images\nreveal the presence of a hot core internally heated by an intermediate mass\nprotostar, and a circumstellar rotating disk around the HW2 radio jet with size\n600AUx100AU and mass of 1M_sun. Keplerian rotation for the disk velocity\ngradient of 5 kms-1 requires a 9 M_sun central star, which cannot explain the\ntotal luminosity observed in the region. This may indicate that the disk does\nnot rotate with a Keplerian law due to the extreme youth of this object. Our\nhigh sensitivity radiocontinuum image at 7 mm shows in addition to the ionized\njet, an extended emission to the west (and marginally to the south) of the HW2\njet, filling the south-west cavity of the HW2 disk. From the morphology and\nlocation of this free-free continuum emission at centimeter and millimeter\nwavelengths (spectral index of 0.4-1.5), we propose that the disk is\nphotoevaporating due to the UV radiation from the central star. All this\nindicates that the Cepheus A HW2 region harbors a cluster of massive stars.\nDisk accretion seems to be the most plausible way to form massive stars in\nmoderate density/luminosity clusters.", "A systematic approach for the construction of a density functional for van\nder Waals interactions that also accounts for saturation effects is described,\ni.e. one that is applicable at short distances. A very efficient method to\ncalculate the resulting expressions in the case of flat surfaces, a method\nleading to an order reduction in computational complexity, is presented.\nResults for the interaction of two parallel jellium slabs are shown to agree\nwith those of a recent RPA calculation (J.F. Dobson and J. Wang, Phys. Rev.\nLett. 82, 2123 1999). The method is easy to use; its input consists of the\nelectron density of the system, and we show that it can be successfully\napproximated by the electron densities of the interacting fragments. Results\nfor the surface correlation energy of jellium compare very well with those of\nother studies. The correlation-interaction energy between two parallel jellia\nis calculated for all separations d, and substantial saturation effects are\npredicted.", "We present single pointing observations of SiO, HCO$^+$ and H$^{13}$CO$^+$\nfrom the James Clerk Maxwell Telescope towards 23 massive star forming regions\npreviously known to contain molecular outflows and ultracompact HII regions. We\ndetected SiO towards 14 sources and suggest that the non-detections in the\nother nine sources could be due to those outflows being older and without\nongoing shocks to replenish the SiO. We serendipitously detected SO$_2$ towards\n17 sources in the same tuning as HCO$^+$. We detected HCO$^+$ towards all\nsources, and suggest that it is tracing infall in nine cases. For seven infall\ncandidates, we estimate mass infall rates between 1$\\times10^{-2}$ and\n2$\\times10^{-5}$ M$_{\\odot}$ yr$^{-1}$. Seven sources show both SiO detections\n(young outflows) and HCO$^+$ infall signatures. We also find that the abundance\nof H$^{13}$CO$^+$ tends to increase along with the abundance of SiO in sources\nfor which we could determine abundances. We discuss these results with respect\nto current theories of massive star formation via accretion. From this survey,\nwe suggest that perhaps both models of ionized accretion and halted accretion\nmay be important in describing the evolution of a massive protostar (or\nprotostars) beyond the formation of an HII region.", "We present optical spectroscopy of nine cataclysmic binary stars, mostly\ndwarf novae, obtained primarily to determine orbital periods Porb. The stars\nand their periods are LX And, 0.1509743(5) d; CZ Aql, 0.2005(6) d; LU Cam,\n0.1499686(4) d; GZ Cnc, 0.0881(4) d; V632 Cyg, 0.06377(8) d; V1006 Cyg,\n0.09903(9) d; BF Eri, 0.2708804(4) d; BI Ori, 0.1915(5) d; and FO Per, for\nwhich Porb is either 0.1467(4) or 0.1719(5) d.\n  Several of the stars proved to be especially interesting. In BF Eri, we\ndetect the absorption spectrum of a secondary star of spectral type K3 +- 1\nsubclass, which leads to a distance estimate of approximately 1 kpc. However,\nBF Eri has a large proper motion (100 mas/yr), and we have a preliminary\nparallax measurement that confirms the large proper motion and yields only an\nupper limit for the parallax. BF Eri's space velocity is evidently large, and\nit appears to belong to the halo population. In CZ Aql, the emission lines have\nstrong wings that move with large velocity amplitude, suggesting a\nmagnetically-channeled accretion flow. The orbital period of V1006 Cyg places\nit squarely within the 2- to 3-hour \"gap\" in the distribution of cataclysmic\nbinary orbital periods.", "We carry out and analyze new multi-color photometry of the Galactic globular\ncluster (GC) M75 in UBVI and focus on the brighter sequences of the color-\nmagnitude diagram (CMD), with particular emphasis on their location in U-based\nCMD. Specifically, we study the level both of the horizontal (HB) and red giant\nbranches (RGB) relative to the main-sequence turnoff (TO) in the U magnitude.\nAlong with the presented photometry of M75, we use our collection of\nphotometric data on GCs belonging to the metal-poor range, [Fe/H]zw<-1.1 dex,\nobtained from observations with different equipment, but calibrated by standard\nstars situated in the observed cluster fields. We confirm our earlier finding,\nand extend it to a larger magnitude range.We demonstrate that DeltaU_{TO}^{BHB}\nexpressing the difference in U magnitude between the TO point and the level of\nthe blue HB, near its red boundary, of the metal-poor GCs observed with the\nEMMI camera of the NTT/ESO telescope is about 0.4-0.5 mag smaller as compared\nto GCs observed with the 100\" telescope and 1.3 m Warsaw telescope of the Las\nCampanas Observatory. At the same time, Delta U_{TO}^{RGB}, the difference in U\nmagnitude between the TO and RGB inflection (brightest) points, does not show\nsuch an apparent dependence on the characteristics of U filters used, but it\ndepends on cluster metallicity. We have shown, for the first time, the\ndependence of the parameter DeltaU_{TO}^{RGB} on [Fe/H] and have estimated its\nanalytical expression, by assuming a linear relation between the parameter and\nmetallicity. Its slope, Delta U_{TO}^{RGB}/Delta [Fe/H]~1.2 mag/dex, is approx.\na factor of two steeper than that of the dependence of the RGB bump position in\nthe V magnitude on metallicity. The asymptotic giant branch (AGB) clump and\nfeatures of the RGB luminosity function (LF) of M75 are also discussed.", "Kibble and Zurek have provided a unifying causal picture for the appearance\nof topological defects like cosmic strings or vortices at the onset of phase\ntransitions in relativistic QFT and condensed matter systems respectively.\nThere is no direct experimental evidence in QFT, but in condensed matter the\npredictions are largely, but not wholly, supported in superfluid experiments on\nliquid helium. We provide an alternative picture for the initial appearance of\nstrings/vortices that is commensurate with all the experimental evidence from\ncondensed matter and consider some of its implications for QFT.", "We study numerically the stress distribution on the interface between two\nthick elastic media bounded by interfaces that include spatially correlated\nasperities. The interface roughness is described using the self-affine\ntopography that is observed over a very wide range of scales from fractures to\nfaults. We analyse the correlation properties of the normal stress distribution\nwhen the rough surfaces have been brought into full contact. The self affinity\nof the rough surfaces is described by a Hurst exponent H. We find that the\nnormal stress field is also self affine, but with a Hurst exponent H-1.\nFluctations of the normal stress are shown to be important, especially at local\nscales with anti-persistent correlations.", "We report Spitzer Space Telescope photometry of eleven externally-polluted\nwhite dwarfs. Of the nine stars for which we have IRAC photometry, we find that\nGD 40, GD 133 and PG 1015+161 each has an infrared excess that can be\nunderstood as arising from a flat, opaque, dusty disk. GD 56 also has an\ninfrared excess characteristic of circumstellar dust, but a flat-disk model\ncannot reproduce the data unless there are grains as warm as 1700 K and perhaps\nnot even then. Our data support the previous suggestion that the metals in the\natmosphere of GD 40 are the result of accretion of a tidally-disrupted asteroid\nwith a chondritic composition.", "The 6.4 day classical Cepheid AW Per is a spectroscopic binary with a period\nof 40 years. Analyzing the centroids of HST/STIS spectra obtained in November\n2001, we have determined the angular separation of the binary system. Although\nwe currently have spatially resolved data for a single epoch in the orbit, the\nsuccess of our approach opens the possibility of determining the inclination,\nsini, for the system if the measurements are repeated at additional epochs.\nSince the system is potentially a double lined spectroscopic binary, the\ncombination of spectroscopic orbits for both components and the visual orbit\nwould give the distance to the system and the masses of its components, thereby\nproviding a direct measurement of a Cepheid mass.", "We have analysed four ASCA observations (1994--1995, 1996--1997) and three\nXMM-Newton observations (2005) of this source, in all of which the source is in\nhigh/soft state. We modeled the continuum spectra with relativistic disk model\nkerrbb, estimated the spin of the central black hole, and constrained the\nspectral hardening factor f_col and the distance. If kerrbb model applies, for\nnormally used value of f_col, the distance cannot be very small, and f_col\nchanges with observations.", "We have obtained CCD BVI imaging of the old open clusters Berkeley 32 and\nKing 11. Using the synthetic colour-magnitude diagram method with three\ndifferent sets of stellar evolution models of various metallicities, with and\nwithout overshooting, we have determined their age, distance, reddening, and\nindicative metallicity, as well as distance from the Galactic centre and height\nfrom the Galactic plane. The best parameters derived for Berkeley 32 are:\nsubsolar metallicity (Z=0.008 represents the best choice, Z=0.006 or 0.01 are\nmore marginally acceptable), age = 5.0-5.5 Gyr (models with overshooting;\nwithout overshooting the age is 4.2-4.4 Gyr with poorer agreement),\n(m-M)_0=12.4-12.6, E(B-V)=0.12-0.18 (with the lower value being more probable\nbecause it corresponds to the best metallicity), Rgc ~ 10.7-11 kpc, and |Z| ~\n231-254 pc. The best parameters for King 11 are: Z=0.01, age=3.5-4.75 Gyr,\n(m-M)_0=11.67-11.75, E(B-V)=1.03-1.06, Rgc ~ 9.2-10 kpc, and |Z| ~ 253-387 pc.", "The majority of the globular clusters associated with the Sagittarius dwarf\ngalaxy are faint. In this respect it differs significantly from the globular\ncluster systems surrounding typical giant galaxies. The observation that most\nof globular clusters in the outer halo of the Galaxy are also sub-luminous may\nbe understood by assuming that these clusters once also belonged to faint\ncluster-rich dwarf systems that were subsequently captured and destroyed by the\nMilky Way System.", "We present high sensitivity Very Long Baseline Interferometry (VLBI)\nobservations 806 days after the gamma-ray burst of 2003 March 29 (GRB030329).\nThe angular diameter of the radio afterglow is measured to be 0.347 +- 0.09\nmas, corresponding to 0.99 +- 0.26 pc at the redshift of GRB030329 (z =\n0.1685). The evolution of the image size favors a uniform external density over\nan R^-2 wind-like density profile (at distances of R >~10^18 cm from the\nsource), although the latter cannot be ruled out yet. The current apparent\nexpansion velocity of the image size is only mildly relativistic, suggesting a\nnon-relativistic transition time of t_NR ~ 1 yr. A rebrightening, or at least a\nsignificant flattening in the flux decay, is expected within the next several\nyears as the counter-jet becomes visible (this has not yet been observed). An\nupper limit of <1.9c is set on the proper motion of the flux centroid.", "Accreting T Tauri stars are observed to be less luminous in X-rays than\nnon-accretors, an effect that has been detected in various star forming\nregions. To explain this we have combined, for the first time, a radiative\ntransfer code with an accretion model that considers magnetic fields\nextrapolated from surface magnetograms obtained from Zeeman-Doppler imaging.\nSuch fields consist of compact magnetic regions close to the stellar surface,\nwith extended field lines interacting with the disc. We study the propagation\nof coronal X-rays through the magnetosphere and demonstrate that they are\nstrongly absorbed by the dense gas in accretion columns. The reduction in the\nobserved X-ray emission depends on the field geometry, which may explain why\naccreting T Tauri stars show a larger scatter in their observed X-ray\nluminosity compared to non-accreting stars.", "We report evidence for a planetary companion around the nearby young star HD\n70573. The star is a G type dwarf located at a distance of 46 pc with age\nestimation between 20 and 300 Myrs. We carried out spectroscopic observations\nof this star with FEROS at the 2.2 m MPG/ESO telescope at La Silla. Our\nspectroscopic analysis yields a spectral type of G1-1.5V and an age of about\n100 Myrs. Variations in stellar radial velocity of HD 70573 have been monitored\nsince December 2003 until January 2007. The velocity accuracy of FEROS within\nthis period is about 10 m/s. HD 70573 shows a radial velocity variation with a\nperiod of 852 +/- 12 days and a semi-amplitude of 149 +/- 6 m/s. The period of\nthis variation is significantly longer than its rotational period, which is 3.3\ndays. Based on the analysis of the Ca II K emission line, Halpha and Teff\nvariation as stellar activity indicators as well as the lack of a correlation\nbetween the bisector velocity span and the radial velocity, we can exclude the\nrotational modulation and non-radial pulsations as the source of the\nlong-period radial velocity variation. Thus, the presence of a low-mass\ncompanion around the star provides the best explanation for the observed radial\nvelocity variation. Assuming a primary mass m1=1.0 +/- 0.1 Msun for the host\nstar, we calculated a minimum mass of the companion m2sini of 6.1 Mjup, which\nlies in the planetary mass regime, and an orbital semi-major axis of 1.76 AU.\nThe orbit of the planet has an eccentricity of e=0.4. The planet discovery\naround the young star HD 70573 gives an important input for the study of debris\ndisks around young stars and their relation to the presence of planets.", "We discuss the dynamics of ultracold atoms in an optical potential\naccelerated by gravity. The positions and widths of the Wannier-Stark ladder of\nresonances are obtained as metastable states. The metastable Wannier-Bloch\nstates oscillate in a single band with the Bloch period. The width of the\nresonance gives the rate transition to the continuum.", "Collective phenomena in strongly nonequilibrium systems interacting with\nelectromagnetic field are considered. Such systems are described by complicated\nnonlinear differential or integro-differential equations. The aim of this\nreview is to show that many nonlinear collective phenomena can be successfully\ntreated by a recently developed method called the Scale Separation Approach\nwhose name is due to the idea of separating different characteristic space-time\nscales existing in nonequilibrium statistical systems. This approach is rather\ngeneral and can be applied to various nonequilibrium physical problems, several\nof which are discussed here. The problems considered not only serve as\nillustrations of the method but are quite important by themselves presenting\ninteresting physical effects, such as Collective Liberation of Light, Turbulent\nPhoton Filamentation, Superradiant Spin Relaxation, Negative Electric Current,\nand Magnetic Semiconfinement of Atoms.", "We introduce VErsatile SPectral Analysis (VESPA): a new method which aims to\nrecover robust star formation and metallicity histories from galactic spectra.\nVESPA uses the full spectral range to construct a galaxy history from synthetic\nmodels. We investigate the use of an adaptative parametrization grid to recover\nreliable star formation histories on a galaxy-by-galaxy basis. Our goal is\nrobustness as opposed to high resolution histories, and the method is designed\nto return high time resolution only where the data demand it. In this paper we\ndetail the method and we present our findings when we apply VESPA to synthetic\nand real Sloan Digital Sky Survey (SDSS) spectroscopic data. We show that the\nnumber of parameters that can be recovered from a spectrum depends strongly on\nthe signal-to-noise, wavelength coverage and presence or absence of a young\npopulation. For a typical SDSS sample of galaxies, we can normally recover\nbetween 2 to 5 stellar populations. We find very good agreement between VESPA\nand our previous analysis of the SDSS sample with MOPED.", "The Sun was recently predicted to be an extended source of gamma-ray\nemission, produced by inverse-Compton scattering of cosmic-ray electrons with\nthe solar radiation. The emission was predicted to contribute to the diffuse\nextragalactic background even at large angular distances from the Sun. While\nthis emission is expected to be readily detectable in future by GLAST, the\nsituation for available EGRET data is more challenging. We present a detailed\nstudy of the EGRET database, using a time dependent analysis, accounting for\nthe effect of the emission from 3C 279, the moon, and other sources, which\ninterfere with the solar signal. The technique has been tested on the moon\nsignal, with results consistent with previous work. We find clear evidence for\nemission from the Sun and its vicinity. The observations are compared with our\nmodel for the extended emission.", "We demonstrate that the corrections to the classical Kelvin image theory due\nto finite electron screening length $\\lambda$, recently discussed by Roulet and\nSaint Jean, Am. J. Phys. 68(4) 319, is amenable to an exact closed form\nsolution in terms of an integral involving Bessel functions. An improper choice\nof boundary conditions is rectified as well, enabling also a complete solution\nfor all potentials - both inside and outside the metal surface.", "Using a prototype model, we study the influence of gauge fluctuations on\nfermion pairing order parameter which has the gauge symmetry, and demonstrate\nthat the gauge fluctuations can destroy the long range order of the fermion\npairing order parameter, and make it only have short range correlation. If this\nparameter is a superconducting order parameter, we show that the Meissner\neffect of the system keeps intact, and the system is in the superconducting\nstate even though the long range order of the superconducting order parameter\nis destroied by the gauge fluctuations. Our calculations support that the\npseudo-gap region of the high Tc cuprate superconductivity is a spin pseudo-gap\nregion rather than an electron pre-paired region.", "We analyze the observations of the transient X-ray pulsar 4U 0115+63 with the\nRXTE and INTEGRAL observatories in a wide X-ray (3-100 keV) energy band during\nits intense outbursts in 1999 and 2004. The energy of the fundamental harmonic\nof the cyclotron resonance absorption line near the maximum of the X-ray flux\nfrom the source (luminosity range 5x10^{37} - 2x10^{38} erg/s) is ~11 keV. When\nthe pulsar luminosity falls below ~5x10^{37} erg/s, the energy of the\nfundamental harmonic is displaced sharply toward the high energies, up to ~16\nkeV. Under the assumption of a dipole magnetic field configuration, this change\nin cyclotron harmonic energy corresponds to a decrease in the height of the\nemitting region by ~2 km, while other spectral parameters, in particular, the\ncutoff energy, remain essentially constant. At a luminosity ~7x10^{37} erg/s,\nfour almost equidistant cyclotron line harmonics are clearly seen in the\nspectrum. This suggests that either the region where the emission originates is\ncompact or the emergent spectrum from different (in height) segments of the\naccretion column is uniform. We have found significant pulse profile variations\nwith energy, luminosity, and time. In particular, we show that the profile\nvariations from pulse to pulse are not reduced to a simple modulation of the\naccretion rate specified by external conditions.", "Young energetic pulsars will likely be the largest class of Galactic sources\nobserved by GLAST, with many hundreds detected. Many will be unknown as radio\npulsars, making pulsation detection dependent on radio and/or x-ray\nobservations or on blind periodicity searches of the gamma-rays. Estimates for\nthe number of pulsars GLAST will detect in blind searches have ranged from tens\nto many hundreds. I argue that the number will be near the low end of this\nrange, partly due to observations being made in a scanning as opposed to a\npointing mode. This paper briefly reviews how blind pulsar searches will be\nconducted using GLAST, what limits these searches, and how the computations and\nstatistics scale with various parameters.", "We report the discovery of 14 quasars in the vicinity of HE2347-4342, one of\nthe two quasars whose intergalactic HeII forest has been resolved with FUSE. By\nanalysing the HI and the HeII opacity variations separately, no transverse\nproximity effect is detected near three foreground quasars of HE2347-4342:\nQSOJ23503-4328 (z=2.282, $\\vartheta=3.59$ arcmin), QSOJ23500-4319 (z=2.302,\n$\\vartheta=8.77$ arcmin) and QSOJ23495-4338 (z=2.690, $\\vartheta=16.28$\narcmin). This is primarily due to line contamination and overdensities probably\ncreated by large-scale structure. By comparing the HI absorption and the\ncorresponding HeII absorption, we estimated the fluctuating spectral shape of\nthe extragalactic UV radiation field along this line of sight. We find that the\nUV spectral shape near HE2347-4342 and in the projected vicinity of the three\nforeground quasars is statistically harder than expected from UV background\nmodels dominated by quasars. In addition, we find three highly ionised metal\nline systems near the quasars. However, they do not yield further constraints\non the shape of the ionising field. We conclude that the foreground quasars\nshow a transverse proximity effect that is detectable as a local hardening of\nthe UV radiation field, although the evidence is strongest for QSOJ23495-4338.\nThus, the relative spectral hardness traces the proximity effect also in\noverdense regions prohibiting the traditional detection in the HI forest.\nFurthermore, we emphasise that softening of quasar radiation by radiative\ntransfer in the intergalactic medium is important to understand the observed\nspectral shape variations. From the transverse proximity effect of\nQSOJ23495-4338 we obtain a lower limit on the quasar lifetime of ~25 Myr.", "At semiconductor-metal junctions, the Schottky barrier height is generally\nfixed by \"Fermi-level pinning\". We find that when a semiconducting carbon\nnanotube is end-contacted to a metal (the optinal geometry for nanodevices),\nthe behavior is radically different. Even when the Fermi level is fully\n\"pinned\" at the interface, the turn-on voltage is that expected for the\nunpinned junction. Thus the threshold may be adjusted for optimal device\nperformance, which is not possible in planar contacts. Similar behavior is\nexpected at heterojunctions between nanotubes and semiconductors.", "We apply the theory of elasticity to study the effects of skyrmion mass on\nlattice dynamics in quantum Hall systems. We find that massive Skyrme lattices\nbehave like a Wigner crystal in the presence of a uniform perpendicular\nmagnetic field. We make a comparison with the microscopic Hartree-Fock results\nto characterize the mass of quantum Hall skyrmions at $\\nu=1$ and investigate\nhow the low temperature phase of Skyrme lattices may be affected by the\nskyrmion mass.", "We study the population of satellite galaxies formed in a suite of\nN-body/gasdynamical simulations of galaxy formation in a LCDM universe. We find\nlittle spatial or kinematic bias between the dark matter and the satellite\npopulation. The velocity dispersion of the satellites is a good indicator of\nthe virial velocity of the halo: \\sigma_{sat}/V_{vir}=0.9 +/- 0.2. Applied to\nthe Milky Way and M31 this gives V_{vir}^{MW}=109 +/- 22$ km/s and\nV_{vir}^{M31} = 138 +/- 35 km/s, respectively, substantially lower than the\nrotation speed of their disk components. The detailed kinematics of simulated\nsatellites and dark matter are also in good agreement. By contrast, the stellar\nhalo of the simulated galaxies is kinematically and spatially distinct from the\npopulation of surviving satellites. This is because the survival of a satellite\ndepends on mass and on time of accretion; surviving satellites are biased\ntoward low-mass systems that have been recently accreted by the galaxy. Our\nresults support recent proposals for the origin of the systematic differences\nbetween stars in the Galactic halo and in Galactic satellites: the elusive\n``building blocks'' of the Milky Way stellar halo were on average more massive,\nand were accreted (and disrupted) earlier than the population of dwarfs that\nhas survived self-bound until the present.", "The duality approach in 2-{\\it dim} two-component regular checkerboards was\nextended onto piezoelectricity and piezomagnetism problems. There are found a\nrelation for effective piezoelectric and piezomagnetic modules for the\ncheckerboard with $p6^{\\prime} mm^{\\prime}$-plane symmetry group ({\\em\ndichromatic triangle}).\n  \\pacs{Pacs: 73.50.Bk,Jt, 75.70.Ak, 77.65.-j, 77.84.Lf}", "Discovered in 1995 at the Caltech Submillimeter Observatory (CSO), the\nvibrationally-excited water maser line at 658 GHz (455 micron) is seen in\noxygen-rich giant and supergiant stars. Because this maser can be so strong (up\nto thousands of Janskys), it was very helpful during the commissioning phase of\nthe highest frequency band (620-700 GHz) of the Submillimeter Array (SMA)\ninterferometer. From late 2002 to early 2006, brief attempts were made to\nsearch for emission from additional sources beyond the original CSO survey.\nThese efforts have expanded the source count from 10 to 16. The maser emission\nappears to be quite compact spatially, as expected from theoretical\nconsiderations; thus these objects can potentially be used as atmospheric phase\ncalibrators. Many of these objects also exhibit maser emission in the\nvibrationally-excited SiO maser at 215 GHz. Because both maser lines likely\noriginate from a similar physical region, these objects can be used to test\ntechniques of phase transfer calibration between millimeter and submillimeter\nbands. The 658 GHz masers will be important beacons to assess the performance\nof the Atacama Large Millimeter Array (ALMA) in this challenging high-frequency\nband.", "Precise resonant experiments on Fe$_{8}$ magnetic clusters have been\nconducted down to 1.2 K at various tranverse magnetic fields, using a\ncylindrical resonator cavity with 40 different frequencies between 37 GHz and\n110 GHz. All the observed resonances for both single crystal and oriented\npowder, have been fitted by the eigenstates of the hamiltonian ${\\cal\nH}=-DS_z^2+ES_x^2-g\\mu_B{\\bf H}\\cdot {\\bf S}$. We have identified the\nresonances corresponding to the coherent quantum oscillations for different\norientations of spin S = 10.", "Spielman et al. have recently observed a large zero-bias peak in the tunnel\nconductance of a bi-layer system in a quantum Hall ferromagnet state. We argue\nthat disorder-induced topological defects in the pseudospin order parameter\nlimit the peak size and destroy the predicted Josephson effect. We predict that\nthe peak would be split and shifted by an in-plane magnetic field in a way that\nmaps the dispersion relation of the ferromagnet's Goldstone mode. We also\npredict resonant structures in the DC I-V characteristic under bias by an {\\em\nac} electric field.", "We report the detection of a radial velocity companion to SDSS\nJ091709.55+463821.8, the lowest mass white dwarf currently known with\nM~0.17Msun. The radial velocity of the white dwarf shows variations with a\nsemi-amplitude of 148.8 km/s and a period of 7.5936 hours, which implies a\ncompanion mass of M > 0.28Msun. The lack of evidence of a companion in the\noptical photometry forces any main-sequence companion to be smaller than\n0.1Msun, hence a low mass main sequence star companion is ruled out for this\nsystem. The companion is most likely another white dwarf, and we present\ntentative evidence for an evolutionary scenario which could have produced it.\nHowever, a neutron star companion cannot be ruled out and follow-up radio\nobservations are required to search for a pulsar companion.", "The orbits of stars close to a massive black hole are nearly Keplerian\nellipses. Such orbits exert long term torques on each other, which lead to an\nenhanced angular momentum relaxation known as resonant relaxation. Under\ncertain conditions, this process can modify the angular momentum distribution\nand affect the interaction rates of the stars with the massive black hole more\nefficiently than non-resonant relaxation. The torque on an orbit exerted by the\ncluster depends on the eccentricity of the orbit. In this paper, we calculate\nthis dependence and determine the resonant relaxation timescale as a function\nof eccentricity. In particular, we show that the component of the torque that\nchanges the magnitude of the angular momentum is linearly proportional to\neccentricity, so resonant relaxation is much more efficient on eccentric orbits\nthan on circular orbits.", "We propose a new method for calculating total energies of systems of\ninteracting electrons, which requires little more computational resources than\nstandard density-functional theories. The total energy is calculated within the\nframework of many-body perturbation theory by using an efficient model of the\nself-energy, that nevertheless retains the main features of the exact operator.\nThe method shows promising performance when tested against quantum Monte Carlo\nresults for the linear response of the homogeneous electron gas and structural\nproperties of bulk silicon.", "The X-ray transient XMMU J174716.1-281048 was serendipitously discovered with\nXMM-Newton in 2003. It lies about 0.9 degrees off the Galactic Centre and its\nspectrum shows a high absorption (~8 x 10E22 cm^(-2)). Previous X-ray\nobservations of the source field performed in 2000 and 2001 did not detect the\nsource, indicative of a quiescent emission at least two orders of magnitude\nfainter. The low luminosity during the outburst (~5 x 10E34 erg/s at 8 kpc)\nindicates that the source is a member of the ``very faint X-ray transients''\nclass. On 2005 March 22nd the INTEGRAL satellite caught a possible type-I X-ray\nburst from the new INTEGRAL source IGR J17464-2811, classified as fast X-ray\ntransient. This source was soon found to be positionally coincident, within the\nuncertainties, with XMMU J174716.1-281048. Here we report data analysis of the\nX-ray burst observed with the IBIS and JEM-X telescopes and confirm the type-I\nburst nature. We also re-analysed XMM-Newton and Chandra archival observations\nof the source field. We discuss the implications of these new findings,\nparticularly related to the source distance as well as the source\nclassification.", "We present measurements on nanomechanical resonators operating in the radio\nfrequency range. We apply a setup which allows the comparison of two schemes of\ndisplacement detection for mechanical resonators, namely conventional power\nreflection measurements of a probing signal and direct detection by capacitive\ncoupling via a gate electrode. For capacitive detection, we employ an on-chip\npreamplifier, which enables direct measurements of the resonator's\ndisplacement. We observe that the response of the mechanical resonator depends\non the detection technique applied, which is verified in model calculations. We\nshow results on the detection of subharmonics.-Paper withdrawn", "Microlensing is a proven extrasolar planet search method that has already\nyielded the detection of four exoplanets. These detections have changed our\nunderstanding of planet formation ``beyond the snowline'' by demonstrating that\nNeptune-mass planets with separations of several AU are common. Microlensing is\nsensitive to planets that are generally inaccessible to other methods, in\nparticular cool planets at or beyond the snowline, very low-mass (i.e.\nterrestrial) planets, planets orbiting low-mass stars, free-floating planets,\nand even planets in external galaxies. Such planets can provide critical\nconstraints on models of planet formation, and therefore the next generation of\nextrasolar planet searches should include an aggressive and well-funded\nmicrolensing component. When combined with the results from other complementary\nsurveys, next generation microlensing surveys can yield an accurate and\ncomplete census of the frequency and properties of planets, and in particular\nlow-mass terrestrial planets.", "Unbiased angular diameter measurements are required for accurate distances to\nCepheids using the interferometric Baade Wesselink method (IBWM). The precision\nof this technique is currently limited by interferometric measurements at the\n1.5% level. At this level, the center-to-limb darkening (CLD) and the presence\nof circumstellar envelopes (CSE) seem to be the two main sources of bias. The\nobservations we performed aim at improving our knowledge of the interferometric\nvisibility profile of Cepheids. In particular, we assess the systematic\npresence of CSE around Cepheids in order determine accurate distances with the\nIBWM free from CSE biased angular diameters. We observed a Cepheid (Y Oph) for\nwhich the pulsation is well resolved and a non-pulsating yellow supergiant\n(alpha Per) using long-baseline near-infrared interferometry. We interpreted\nthese data using a simple CSE model we previously developed. We found that our\nobservations of alpha Per do not provide evidence for a CSE. The measured CLD\nis explained by an hydrostatic photospheric model. Our observations of Y Oph,\nwhen compared to smaller baseline measurements, suggest that it is surrounded\nby a CSE with similar characteristics to CSE found previously around other\nCepheids. We have determined the distance to Y Oph to be d=491+/-18 pc.\nAdditional evidence points toward the conclusion that most Cepheids are\nsurrounded by faint CSE, detected by near infrared interferometry: after\nobserving four Cepheids, all show evidence for a CSE. Our CSE non-detection\naround a non-pulsating supergiant in the instability strip, alpha Per, provides\nconfidence in the detection technique and suggests a pulsation driven mass-loss\nmechanism for the Cepheids.", "We define a new set of excitations in the XY model which we call ``fractional\nvortices''. In the frustrated XY model containing $\\pi$ bonds, we make the\nansatz that the ground state configurations can be characterized by pairs of\noppositely charged fractional vortices. For a chain of $\\pi$ bonds, the ground\nstate energy and the phase configurations calculated on the basis of this\nansatz agree well with the results from direct numerical simulations. Finally,\nwe discuss the possible connection of these results to some recent experiments\nby Kirtley {\\it et al} [Phys. Rev. B {\\bf 51}, R12057 (1995)] on high-T$_c$\nsuperconductors where fractional flux trapping was observed along certain grain\nboundaries.", "An analysis of the relation between radio surface brightness and diameter,\nso-called Sigma-D relation, for planetary nebulae (PNe) is presented: i) the\ntheoretical Sigma-D relation for the evolution of bremsstrahlung surface\nbrightness is derived; ii) contrary to the results obtained earlier for the\nGalactic supernova remnant (SNR) samples, our results show that the updated\nsample of Galactic PNe does not severely suffer from volume selection effect -\nMalmquist bias (same as for the extragalactic SNR samples) and; iii) we\nconclude that the empirical Sigma-D relation for PNe derived in this paper is\nnot useful for valid determination of distances for all observed PNe with\nunknown distances.", "We report on the discovery of six new ZZ Ceti stars. They were selected as\ncandidates based on preparatory photometric observations of objects from the\nHamburg Quasar Survey (HQS), and based on the spectra of the Supernova Ia\nProgenitor Survey (SPY). Time-series photometry of 19 candidate stars was\ncarried out at the Nordic Optical Telescope (NOT) at Roque de Los Muchachos\nObservatory, Spain. The new variables are relatively bright, 15.4<B<16.6. Among\nthem is WD1150-153, which is the third ZZ Ceti star that shows photospheric\nCaII in its spectrum.", "We study the dynamic response of a [111] quantum impurity, such as lithium or\ncyanide in alkali halides, with respect to an external field coupling to the\nelastic quadrupole moment. Because of the particular level structure of a\neight-state system on a cubic site, the elastic response function shows a\nbiexponential relaxation feature and a van Vleck type contribution with a\nresonance frequency that is twice the tunnel frequency $\\Delta/\\hbar$. This\nbasically differs from the dielectric response that does not show relaxation.\nMoreover, we show that the elastic response of a [111] impurity cannot be\nreduced to that of a two-level system. In the experimental part, we report on\nrecent sound velocity and internal friction measurements on KCl doped with\ncyanide at various concentrations. At low doping (45 ppm) we find the dynamics\nof a single [111] impurity, whereas at higher concentrations (4700 ppm) the\nelastic response rather indicates strongly correlated defects. Our theoretical\nmodel provides a good description of the temperature dependence of $\\delta v/v$\nand $Q^{-1}$ at low doping, in particular the relaxation peaks, the absolute\nvalues of the amplitude, and the resonant contributions. From our fits we\nobtain the value of the elastic deformation potential $\\gamma_t=0.192$ eV.", "We review the X-ray studies of the highest redshift quasars, focusing on the\nresults obtained with Chandra and XMM-Newton. Overall, the X-ray and broad-band\nproperties of z>4 quasars and local quasars are similar, suggesting that the\nsmall-scale X-ray emission regions of AGN are insensitive to the significant\nchanges occurring at z=0-6.", "We describe a simple and accurate framework for modeling the statistical\nbehavior of both fully developed turbulence and short-term dynamics of\nfinancial markets based on the formalism of Tsallis' generalized non-extensive\nthermostatistics. Within this framework, we show that intermittency and\nnon-extensivity are naturally linked by the entropic parameter q. Our results,\nconcerning both probability density functions and structure functions exponents\nare in very good agreement with experimental data.", "We extend standard k.p theory to take into account periodic perturbations\nwhich are rapidly oscillating with a wavelength of a few lattice constants. Our\ngeneral formalism allows us to explicitly consider the Bragg reflections due to\nthe perturbation-induced periodicity. As an example we calculate the effective\nmasses in the lowest two conduction bands of spontaneously ordered GaInP_2 as a\nfunction of the degree of ordering. Comparison of our results for the lowest\nconduction band to available experimental data and to first principle\ncalculations shows good agreement.", "Context. Searching for planets in open clusters allows us to study the\neffects of dynamical environment on planet formation and evolution.\n  Aims. Considering the strong dependence of planet frequency on stellar\nmetallicity, we studied the metal rich old open cluster NGC 6791 and searched\nfor close-in planets using the transit technique.\n  Methods. A ten-night observational campaign was performed using the\nCanada-France-Hawaii Telescope (3.6m), the San Pedro M\\'artir telescope (2.1m),\nand the Loiano telescope (1.5m). To increase the transit detection probability\nwe also made use of the Bruntt et al. (2003) eight-nights observational\ncampaign. Adequate photometric precision for the detection of planetary\ntransits was achieved.\n  Results. Should the frequency and properties of close-in planets in NGC 6791\nbe similar to those orbiting field stars of similar metallicity, then detailed\nsimulations foresee the presence of 2-3 transiting planets. Instead, we do not\nconfirm the transit candidates proposed by Bruntt et al. (2003). The\nprobability that the null detection is simply due to chance coincidence is\nestimated to be 3%-10%, depending on the metallicity assumed for the cluster.\n  Conclusions. Possible explanations of the null-detection of transits include:\n(i) a lower frequency of close-in planets in star clusters; (ii) a smaller\nplanetary radius for planets orbiting super metal rich stars; or (iii)\nlimitations in the basic assumptions. More extensive photometry with 3-4m class\ntelescopes is required to allow conclusive inferences about the frequency of\nplanets in NGC 6791.", "We make use of new near and mid-IR photometry of the Pleiades cluster in\norder to help identify proposed cluster members. We also use the new photometry\nwith previously published photometry to define the single-star main sequence\nlocus at the age of the Pleiades in a variety of color-magnitude planes.\n  The new near and mid-IR photometry extend effectively two magnitudes deeper\nthan the 2MASS All-Sky Point Source catalog, and hence allow us to select a new\nset of candidate very low mass and sub-stellar mass members of the Pleiades in\nthe central square degree of the cluster. We identify 42 new candidate members\nfainter than Ks =14 (corresponding to 0.1 Mo). These candidate members should\neventually allow a better estimate of the cluster mass function to be made down\nto of order 0.04 solar masses.\n  We also use new IRAC data, in particular the images obtained at 8 um, in\norder to comment briefly on interstellar dust in and near the Pleiades. We\nconfirm, as expected, that -- with one exception -- a sample of low mass stars\nrecently identified as having 24 um excesses due to debris disks do not have\nsignificant excesses at IRAC wavelengths. However, evidence is also presented\nthat several of the Pleiades high mass stars are found to be impacting with\nlocal condensations of the molecular cloud that is passing through the Pleiades\nat the current epoch.", "Clumping in the winds of massive stars may significantly reduce empirical\nmass-loss rates, and which in turn may have a large impact on our understanding\nof massive star evolution. Here, we investigate wind-clumping through the\nlinear polarization induced by light scattering off the clumps. Through the use\nof an analytic wind clumping model, we predict the time evolution of the linear\npolarimetry over a large parameter space. We concentrate on the Luminous Blue\nVariables, which display the greatest amount of polarimetric variability and\nfor which we recently conducted a spectropolarimetric survey. Our model results\nindicate that the observed level of polarimetric variability can be reproduced\nfor two regimes of parameter space: one of a small number of massive,\noptically-thick clumps; and one of a very large number of low-mass clumps.\nAlthough a systematic time-resolved monitoring campaign is required to\ndistinguish between the two scenarios, we currently favour the latter, given\nthe short timescale of the observed polarization variability. As the\npolarization is predicted to scale linearly with mass-loss rate, we anticipate\nthat all hot stars with very large mass-loss rates should display polarimetric\nvariability. This is consistent with recent findings that intrinsic\npolarization is more common in stars with strong H$\\alpha$ emission.", "We investigate the dissipation of magnetic flux in primordial star-forming\nclouds throughout their collapse including the run-away collapse phase as well\nas the accretion phase. We solve the energy equation and the non-equilibrium\nchemical reactions in the collapsing gas, in order to obtain the radial\ndistribution of the ionized fraction during the collapse. As a result, we find\nthe ionized fraction is high enough for the magnetic field to couple with the\ngas throughout the evolution of the cloud. This result suggests that the jet\nformation from protostars as well as the activation of magneto-rotational\ninstability in the accretion disk are enabled in the presence of the\ncosmological seed magnetic flux proposed by Langer et al.(2003).", "Radiation from acoustic sources located inside randomly-layered structures is\nstudied using the transfer matrix method. It is shown that in contrast to the\nperiodically layered cases where the radiation can be either enhanced or\ninhibited depending on the frequency, and the characteristics and the material\ncomposition of the structures, in the random structures the radiation is always\ninhibited. The degree of inhibition depends on the acoustic frequency, number\nof random layers, and the randomness and acoustic parameters of the structures.\nBoth spherically and cylindrically random structures are considered. The\nresults point to the possibility of designing sonic waveguide devices which\nwill not suffer from the energy loss caused by radiation, thus allowing\neffective energy confinement or long-range energy propagation.", "The linear and nonlinear dynamical susceptibilities of a two level system are\ncalculated as it undergoes a transition to a decoherent state. Analogously to\nthe Glover-Tinkham-Ferrell sum rule of superconductivity, spectral weight in\nthe linear susceptibility is continuously transferred from a finite frequency\nresonance to nearly zero frequency, corresponding to a broken symmetry in the\nthermodynamic limit. For this reason, the behavior of the present model (the\nMermin model) differs significantly from the spin-boson model. The third order\nnonlinear susceptibility, corresponding to two-photon absorption, has an\nunexpected non-monotonic behavior as a function of the environmental coupling,\nreaching a maximum within the decoherent phase of the model. Both linear and\nnonlinear susceptibilities may be expressed in a universal form.", "We consider a weakly-interacting, harmonically-trapped Bose-Einstein\ncondensed gas under rotation and investigate the connection between the\nenergies obtained from mean-field calculations and from exact diagonalizations\nin a subspace of degenerate states. From the latter we derive an approximation\nscheme valid in the thermodynamic limit of many particles. Mean-field results\nare shown to emerge as the correct leading-order approximation to exact\ncalculations in the same subspace.", "By combining high-resolution (HST-WFPC2) and wide-field ground based (2.2m\nESO-WFI) and space (GALEX) observations, we have collected a multi-wavelength\nphotometric data base (ranging from the far UV to the near infrared) of the\ngalactic globular cluster NGC1904 (M79). The sample covers the entire cluster\nextension, from the very central regions up to the tidal radius. In the present\npaper such a data set is used to study the BSS population and its radial\ndistribution. A total number of 39 bright ($m_{218}\\le 19.5$) BSS has been\ndetected, and they have been found to be highly segregated in the cluster core.\nNo significant upturn in the BSS frequency has been observed in the outskirts\nof NGC 1904, in contrast to other clusters (M 3, 47 Tuc, NGC 6752, M 5) studied\nwith the same technique. Such evidences, coupled with the large radius of\navoidance estimated for NGC 1904 ($r_{avoid}\\sim 30$ core radii), indicate that\nthe vast majority of the cluster heavy stars (binaries) has already sunk to the\ncore. Accordingly, extensive dynamical simulations suggest that BSS formed by\nmass transfer activity in primordial binaries evolving in isolation in the\ncluster outskirts represent only a negligible (0--10%) fraction of the overall\npopulation.", "Pinpointing the progenitors of long duration gamma-ray bursts (LGRBs) remains\nan extremely important question, although it is now clear that at least a\nfraction of LGRBs originate in the core collapse of massive stars in type Ic\nsupernovae, the pathways to the production of these stars, and their initial\nmasses, remain uncertain. Rotation is thought to be vital in the creation of\nLGRBs, and it is likely that black hole creation is also necessary. We suggest\nthat these two constraints can be met if the GRB progenitors are very massive\nstars (>20 solar masses) and are formed in tight binary systems. Using simple\nmodels we compare the predictions of this scenario with observations and find\nthat the location of GRBs on their host galaxies are suggestive of\nmain-sequence masses in excess of 20 solar masses, while 50% of the known\ncompact binary systems may have been sufficiently close to have had the\nnecessary rotation rates for GRB creation. Thus, massive stars in compact\nbinaries are a likely channel for at least some fraction of LGRBs.", "Based on the tight binding method with hopping integral between the\nnearest-neighbor atoms, an oscillator strength $\\int_0^{\\infty} \\d \\omega {\\rm\nRe} \\sigma (\\omega)$ is discussed for armchair and metallic zigzag carbon\nnanotubes. The formulae of the oscillator strength are derived for both types\nof nanotubes and are compared with the result obtained by a linear chain model.\nIn addition, the doping dependence is investigated in the absence of Coulomb\ninteraction. It is shown that the oscillator strength of each carbon nanotube\nshows qualitatively the same doping dependence, but the fine structure is\ndifferent due to it's own peculiar band structure. Some relations independent\nof the radius of the tube are derived, and a useful formula for determining the\namount of doping is proposed.", "We report new detailed surface U, B, V, R, and I photometry of 81 stellar\nstructures in the disk of the barred galaxy NGC 3367. The images show many\ndifferent structures indicating that star formation is going on in the most\npart of the disk. NGC 3367 is known to have a very high concentration of\nmolecular gas distribution in the central regions of the galaxy and bipolar\nsynchrotron emission from the nucleus with two lobes (at 6 kpc) forming a\ntriple structure similar to a radio galaxy. We have determined the U, B, V, R,\nand I magnitudes and U - B, B - V, U - V, and V - I colors for the central\nregion (nucleus), a region which includes supernovae 2003 AA, and 79 star\nassociations throughout NGC 3367. Estimation of ages of star associations is\nvery difficult due to several factors, among them: filling factor, metallicity,\nspatial distribution of each structure and the fact that we estimated the\nmagnitudes with a circular aperture of 16 pixels in diameter, equivalent to\n$6''.8\\sim1.4$ kpc. However, if the colors derived for NGC 3367 were similar to\nthe colors expected of star clusters with theoretical evolutionary star tracks\ndeveloped for the LMC and had a similar metallicity, NGC 3367 show 51 percent\nof the observed structures with age type SWB I (few tens of Myrs), with seven\nsources outside the bright surface brightness visible disk of NGC 3367.", "We investigate the plasma flow properties inside a Supergranular (SG) cell,\nin particular its interaction with small scale magnetic field structures. The\nSG cell has been identified using the magnetic network (CaII wing brightness)\nas proxy, applying the Two-Level Structure Tracking (TST) to high spatial,\nspectral and temporal resolution observations obtained by IBIS. The full 3D\nvelocity vector field for the SG has been reconstructed at two different\nphotospheric heights. In order to strengthen our findings, we also computed the\nmean radial flow of the SG by means of cork tracing. We also studied the\nbehaviour of the horizontal and Line of Sight plasma flow cospatial with\ncluster of bright CaII structures of magnetic origin to better understand the\ninteraction between photospheric convection and small scale magnetic features.\nThe SG cell we investigated seems to be organized with an almost radial flow\nfrom its centre to the border. The large scale divergence structure is probably\ncreated by a compact region of constant up-flow close to the cell centre. On\nthe edge of the SG, isolated regions of strong convergent flow are nearby or\ncospatial with extended clusters of bright CaII wing features forming the knots\nof the magnetic network.", "We characterize in details the aging properties of the ferroelectric phase of\nK Ta_{1-x} Nb_x O_3 (KTN), where both rejuvenation and (partial) memory are\nobserved. In particular, we carefully examine the frequency dependence of\nseveral quantities that characterize aging, rejuvenation and memory. We find a\nmarked subaging behaviour, with an a.c. dielectric susceptiblity scaling as\n$\\omega \\sqrt{t_w}$, where $t_w$ is the waiting time. We suggest an\ninterpretation in terms of pinned domain walls, much along the lines proposed\nfor aging in a disordered ferromagnet, where both domain wall reconformations\nand overall (cumulative) domain growth are needed to rationalize the\nexperimental findings.", "Following the synthesis of aligned single-wall carbon nanotubes in the\nchannels of AlPO4-5 zeolite single crystals, we present the first X-ray\ndiffraction and diffuse scattering results. They can be analysed in terms of a\npartial filling of the zeolite channels by nanotubes with diameter around 4A.\nThe possible selection of only one type of nanotube during the synthesis, due\nto the constraints imposed by the zeolite host, is discussed.", "A semi-classical theory of coherent light scattering from an elongated sample\nof cold atoms exposed to an off-resonant laser beam is presented. The model,\nwhich is a direct extension of that of the collective atomic recoil laser\n(CARL), describes the emission of two superradiant pulses along the sample's\nmajor axis simultaneous with the formation of a bidimensional atomic grating\ninside the sample. It provides a simple physical picture of the recent\nobservation of collective light scattering from a Bose-Einstein condensate [S.\nInouye et al., Science N.285, p. 571 (1999)]. In addition, the model provides\nan analytical description of the temporal evolution of the scattered light\nintensity which shows good quantitative agreement with the experimental results\nof Inouye et al.", "In He-3 superfluids quantized vorticity can take many different forms: It can\nappear as distributed periodic textures, as sheets, or as lines. In the\nanisotropic He-3A phase in most cases the amplitude of the order parameter\nremains constant throughout the vortex structure and only its orientation\nchanges in space. In the quasi-isotropic He-3B phase vortex lines have a hard\ncore where the order parameter has reduced, but finite amplitude. The different\nstructures have been firmly identified, based on both measurement and\ncalculation. What parallels can be drawn from this information to the new\nunconventional superconductors or Bose-Einstein condensates?", "A 3D layered system of charges with logarithmic interaction parallel to the\nlayers and random dipoles is studied via a novel variational method and an\nenergy rationale which reproduce the known phase diagram for a single layer.\nIncreasing interlayer coupling leads to successive transitions in which charge\nrods correlated in N>1 neighboring layers are nucleated by weaker disorder. For\nlayered superconductors in the limit of only magnetic interlayer coupling, the\nmethod predicts and locates a disorder-induced defect-unbinding transition in\nthe flux lattice. While N=1 charges dominate there, N>1 disorder induced defect\nrods are predicted for multi-layer superconductors.", "The heat capacity of some ferrimagnets has additional structures like a\nshoulder in the Schottky-like peak, or emergence of a second peak when an\nexternal magnetic field is applied. It is shown here that as long as spin\nwave-spin wave interactions are ignored in a ferrimagnet, the ferromagnetic and\nantiferromagnetic elementary excitation spectra give rise to two independent\nheat capacity peaks, one enveloped by the other, which add up to give the peak\nfor the total system. Taking this into account helps understand the additional\nstructures in the peaks. Moreover, the classification of ferrimagnets into\npredominantly antiferromagnetic, ferromagnetic, or a mixture of the two is\nshown to be validated by studying them under additional influences like\ndimerization and frustration. Because these two are shown to influence the\nferromagnetic and antiferromagnetic dispersion relations - and hence the\nquantities like heat capacity and magnetic susceptibility - by different\namounts, the characterisation of ferrimagnetic systems ($1,1/2$), ($3/2,1$) and\n($3/2,1/2$) is brought out more clearly. Both these influences enhance\nantiferromagnetic character.", "Context: The transient hard X-ray source IGR J11321-5311 was discovered by\nINTEGRAL on June 2005, during observations of the Crux spiral arm. To date,\nthis is the only detection of the source to be reported by any X/gamma-ray\nmission. Aims: To characterize the behaviour and hence the nature of the source\nthrough temporal and spectral IBIS analysis. Methods: Detailed spectral and\ntemporal analysis has been performed using standard INTEGRAL software OSA\nv.5.1. Results: To date, IGR J11321-5311 has been detected only once. It was\nactive for about 3.5 hours, a short and bright flare lasting about 1.5 hours is\nevident in the IBIS light curve. It reached a peak flux of about 80 mCrab or\n2.2x10E-9 erg cmE-2 sE-1 (20--300 keV),corresponding to a peak luminosity of\n1.1x10E37 erg sE-1 (assuming a distance of 6.5 kpc). During the outburst, the\nsource was detected with a significance of 18 sigma (20--300 keV) and 8 sigma\n(100--300 keV). The spectrum of the total outburst activity (17--300 keV) is\nbest fitted by the sum of a power law (Gamma=0.55+/-0.18) plus a black body\n(kT=1.0{+0.2}_{-0.3} keV), with no evidence for a break up to 300 keV. A\nspectral analysis at Science Window level revealed an evident hardening of the\nspectrum through the outburst. The IBIS data were searched for pulsations with\nno positive result. Conclusions: The X-ray spectral shape and the flaring\nbehaviour favour the hypothesis that IGR J11321-5311 is an Anomalous X-ray\nPulsar, though a different nature can not be firmly rejected at the present\nstage.", "The environment of high-redshift galaxies is characterized by both\nwind-driven outflowing gas and gravitationally infalling streams. To\ninvestigate such galaxy-IGM interplay we have generated synthetic optical\nabsorption line spectra piercing the volume surrounding a starbursting analog\nof a Lyman Break Galaxy selected in a $z \\approx 3$ output from a SPH\nsimulation, including a detailed treatment of mechanical feedback from winds.\nDistributions for several observable species (HI, CIII, CIV, SiII, SiIII, SiIV,\nOVI, OVII, and OVIII) have been derived by post-processing the simulation\noutputs. The hot wind material is characterized by the presence of\nhigh-ionization species such as OVI, OVII, and OVIII (the latter two observable\nonly in X-ray bands); the colder ($T<10^{5.5}$ K) infalling streams can be\ninstead identified by the combined presence of SiII, SiIII, and CIII optical\nabsorption together with OVI that surrounds the cooler gas clumps. However,\nboth line profile and Pixel Optical Depth analysis of the synthetic spectra\nshow that the intergalactic filament in which the wind-blowing galaxy is\nembedded produces absorption signatures that closely mimic those of the wind\nenvironment. We conclude that may be difficult to clearly identify wind-blowing\ngalaxies and their complex gaseous environment at high redshift in optical QSO\nabsorption-line spectra based solely on the observed ion absorption patterns."], "train_labels": ["astro-ph", "astro-ph", "astro-ph", "astro-ph", "cond-mat", "astro-ph", "astro-ph", "cond-mat", "astro-ph", "astro-ph", "cond-mat", "astro-ph", "astro-ph", "cond-mat", "cond-mat", "astro-ph", "cond-mat", "astro-ph", "cond-mat", "astro-ph", "cond-mat", "astro-ph", "astro-ph", "astro-ph", "astro-ph", "astro-ph", "astro-ph", "astro-ph", "astro-ph", "cond-mat", "cond-mat", "astro-ph", "cond-mat", "cond-mat", "cond-mat", "cond-mat", "astro-ph", "astro-ph", "astro-ph", "astro-ph", "astro-ph", "astro-ph", "cond-mat", "cond-mat", "astro-ph", "cond-mat", "astro-ph", "cond-mat", "astro-ph", "cond-mat", "astro-ph", "cond-mat", "cond-mat", "astro-ph", "cond-mat", "cond-mat", "astro-ph", "cond-mat", "cond-mat", "astro-ph", "cond-mat", "astro-ph", 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