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astro-ph/9305013
Molecular Clouds Close to the Galactic Center
We demonstrate that the accretion disk model for the Galactic Center region by Linden et al (1993a) is applicable for at least one order of magnitude in radius from the Galactic Center (10 ... 100 pc). The viscosity $\nu$ is shown to be weakly dependent on the radius $s$: $\nu \sim s^{0.4}$. Finally, we discuss the inf...
1993-05-12
2007-05-23
[ "astro-ph" ]
Peter L. Biermann, Wolfgang J. Duschl, Susanne von Linden
astro-ph/9305012
The Discovery of Two FU Orionis Objects in L1641
We have obtained spectra of the reflection nebulosity illuminated by two heavily embedded IRAS sources in the L1641 molecular cloud, Re 50 and IC 430 (V883 Ori). Examination of these spectra in combination with their other properties indicates that these objects are FU Orionis objects. Our spectrum of L1551 IRS 5 confi...
1993-05-11
2009-10-22
[ "astro-ph" ]
Karen M. Strom and Stephen E. Strom
astro-ph/9305010
Mixed Dark Matter from Axino Distribution
We study the possibility of mixed dark matter obtained through the phase space distribution of a single particle. An example is offered in the context of SUSY models with a Peccei-Quinn symmetry. Axinos in the 100 keV range can naturally have both thermal and non-thermal components. The latter one arises from the light...
1993-05-11
2009-10-22
[ "astro-ph" ]
S.A. Bonometto, F. Gabbiani, A. Masiero
astro-ph/9305009
Testing for Gaussianity Through the Three Point Temperature Correlation Function
One of the crucial aspects of density perturbations that are produced by the standard inflation scenario is that they are Gaussian where seeds produced by topological defects tend to be non-Gaussian. The three point correlation function of the temperature anisotropy of the cosmic microwave background radiation (CBR) pr...
1993-05-09
2009-10-22
[ "astro-ph" ]
Xiaochun Luo and D.N. Schramm
astro-ph/9305007
Large-Scale Clustering in Bubble Models
We analyze the statistical properties of bubble models for the large-scale distribution of galaxies. To this aim, we realize static simulations, in which galaxies are mostly randomly arranged in the regions surrounding bubbles. As a first test, we realize simulations of the Lick map, by suitably projecting the three-di...
1993-05-07
2015-06-24
[ "astro-ph" ]
Luca Amendola & Stefano Borgani
astro-ph/9305008
Statistics of N-body Simulations I. Equal Masess Before Core Collapse
We study the dynamical evolution of idealised stellar systems by averaging results from many $N$-body simulations, each having modest numbers of stars. For isolated systems with stars of uniform mass, we discuss aspects of evolution up to the point of core collapse: relaxation and its $N$-dependence, the evolution of t...
1993-05-07
2015-06-24
[ "astro-ph" ]
Mirek Giersz and Douglas C. Heggie
astro-ph/9305006
A Hydrodynamical Analysis of the Burning of a Neutron Star
The burning of a neutron star by strange matter is analyzed using relativistic combustion theory with a planar geometry. It is shown that such burning is probably neither slow combustion nor simple detonation. Fast combustion without detonation is possible under certain circumstances, but would involve very efficient h...
1993-05-07
2009-10-22
[ "astro-ph" ]
H. T. Cho, K. -W. Ng, and Achilles D. Speliotopoulos
astro-ph/9305005
AGN and galactic sites of cosmic ray origin
We review recent progress in our understanding of the physics of energetic particles in our Galaxy, in active galaxies such as starburst galaxies, in active galactic nuclei and in the jets and radio hot spots of powerful radio galaxies and radioloud quasars. We propose that cosmic rays originate mainly in three sites, ...
1993-05-06
2016-10-26
[ "astro-ph" ]
Peter L. Biermann (Max-Planck-Institut fuer Radioastronomie, Bonn, Germany)
astro-ph/9305003
Cosmic Rays, II. Evidence for a magnetic rotator Wolf Rayet star origin
Based on 1) a conjecture about the mean free path for particle scattering in perpendicular shock geometries, and 2) a model for Wolf Rayet star winds, we argue that explosions of Wolf Rayet stars can lead through diffusive particle acceleration to particle energies up to 3 10^9 GeV. As a test we first demonstrate that ...
1993-05-06
2007-05-23
[ "astro-ph" ]
Peter L. Biermann (1) and Joseph P. Cassinelli (2) ((1) Max-Planck-Institut fuer Radioastronomie, Bonn, Germany, (2) Department for Astronomy, University of Wisconsin, Madison WI, USA)
astro-ph/9305002
Visibility of Gravitational Lenses and the Cosmological Constant Problem
Recent observations suggest appreciable star formation activity in early-type galaxies down to redshift $z\sim 0.5$. If so, there is likely to be dust in these galaxies. We consider the possibility that obscuration by dust can reconcile the observed frequency of gravitational lensing of quasar images with the considera...
1993-05-06
2007-05-23
[ "astro-ph" ]
M. Fukugita and P. J. E. Peebles
astro-ph/9305004
Modelling Non-Axisymmetric Bow Shocks
I present an extension of the thin layer approximation to non-axisymmetric bow shocks. By choosing a suitable set of curvilinear coordinates that matches the geometry of a generally distorted bow shock surface, I derive the fluid equations for the flow. Analytical expansions are given for the matter flow near the bow s...
1993-05-06
2007-05-23
[ "astro-ph" ]
Rino Bandiera
astro-ph/9305001
Large-scale Polarization of the Cosmic Microwave Background Radiation
The anisotropy and polarization of the cosmic microwave background radiation (CMBR) induced by the scalar and tensor metric perturbations are computed in the long-wavelength limit. It is found that the large-scale polarization of CMBR induced by the decaying tensor mode can reach a few percents. This is different from ...
1993-05-03
2009-10-22
[ "astro-ph" ]
Ka Lok Ng and Kin-Wang Ng
astro-ph/9304029
Tidally Induced Elongation and Alignments of Galaxy Clusters
We show that tidal interaction among galaxy clusters can account for their observed alignments and very marked elongation and, consequently, that these characteristics of clusters are actually consistent with them being formed in hierarchical clustering. The well-established distribution of projected axial ratios of cl...
1993-04-30
2014-10-13
[ "astro-ph" ]
Eduard Salvador-Sole and Jose M. Solanes
astro-ph/9304028
Mass Spectrum and Velocity Dispersions During Planetesimals Accumulation - II - Fragmentation
Fragmentation of the planetesimals is found to play a role whose importance is greater than previously believed and depends on the average characteristic size of the primordial planetesimals but not on their mass distribution. In the small size range the mass spectrum is strongly modified with the formation of a small ...
1993-04-29
2009-10-22
[ "astro-ph" ]
P. Barge and R. Pellat
astro-ph/9304027
Hydrodynamic Instability and Coalescence of Binary Neutron Stars
We study the importance of hydrodynamic effects on the evolution of coalescing binary neutron stars. Using an approximate energy functional constructed from equilibrium solutions for polytropic binary configurations, we incorporate hydrodynamic effects into the calculation of the orbital decay driven by gravitational w...
1993-04-28
2009-10-22
[ "astro-ph" ]
D. Lai, F. A. Rasio, and S. L. Shapiro
astro-ph/9304025
Lensing of Invisible Stars by Brown Dwarfs
To detect brown dwarfs in the dark galactic halo through gravitational lensing, experiments follow the luminosity of millions of stars to observe a few lensing events par year. The luminosity of a star too faint to be continuously followed can be temporarily increased above the detection limit by a lensing. The detecti...
1993-04-28
2007-05-23
[ "astro-ph" ]
Alain Bouquet
astro-ph/9304026
Kinematic Signature of a Rotating Bar Near a Resonance
There have been several recent suggestions that the Milky Way has rotating bar-like features based on HI and star count data. In this paper, I show that such features cause distinctive stellar kinematic signatures near OLR and ILR. The effects of these resonances may be observable far from the peak density of the patte...
1993-04-28
2009-10-22
[ "astro-ph" ]
Martin D. Weinberg
astro-ph/9304024
Eigenfrequencies of Radial Pulsations of Strange Quark Stars
We calculate the range of eigenfrequencies of radial pulsations of stable strange quark stars, using the general relativistic pulsation equation and adopting realistic equation of state for degenerate strange quark matter.
1993-04-27
2009-10-22
[ "astro-ph" ]
B. Datta, Pradip K. Sahu, J. D. Anand and A. Goyal
astro-ph/9304023
MACHOs in a Flattened Halo
If massive compact halo objects (\ms) are detected in ongoing searches, then \tsmctlmc, the ratio of the optical depth toward the Small and Large Magellanic Clouds, will be a robust indicator of the flattening of the Galactic dark matter halo. For a spherical halo, \tsmctlmc\ is about 1.45, independent of details of th...
1993-04-26
2009-10-22
[ "astro-ph" ]
Penny D. Sackett and Andrew Gould
astro-ph/9304022
Power Spectrum Analysis of Three-Dimensional Redshift Surveys
We develop a general method for power spectrum analysis of three dimensional redshift surveys. We present rigorous analytical estimates for the statistical uncertainty in the power and we are able to derive a rigorous optimal weighting scheme under the reasonable (and largely empirically verified) assumption that the l...
1993-04-26
2011-05-05
[ "astro-ph" ]
Hume A. Feldman, Nick Kaiser and John A. Peacock
astro-ph/9304021
Quark Neutron Layer Stars
Typical nuclear equations of state and a quark bag model, surprisingly, allow compact stars with alternate layers of neutrons and quarks. One can determine on the basis of the Gibbs free energy which phase, nuclear or quark, is energetically favorable. Using the nuclear equation of state of Wiringa, and a quark equatio...
1993-04-24
2009-10-22
[ "astro-ph" ]
Philip A. Carinhas
astro-ph/9304020
Neutrino Emissivity of Degenerate Quark Matter
An exact numerical calculation of neutrino emissivity of two and three flavour quark matter have been carried out. We find that the neutrino emissivity obtained from the Iwamoto formula is in qualitative agreement with our calculation for two flavour quark matter. For three flavour case, on the other hand we find that ...
1993-04-22
2007-05-23
[ "astro-ph" ]
Sanjay K. Ghosh, S. C. Phatak and Pradip K. Sahu
astro-ph/9304019
Quark Stars in Chiral Colour Dielectric Model
The nonlinear chiral extension of colour dielectric model has been used in the present work to study the properties of quark stars. Assuming that the square of meson fields develop nonzero expectation value, the thermodynamic potential for charge neutral interacting two and three flavour quark matter, in beta equilibri...
1993-04-22
2015-06-24
[ "astro-ph" ]
Sanjay K. Ghosh and Pradip K. Sahu
astro-ph/9304018
The Fundamental Plane of Galaxy Clusters
Velocity dispersion $\sigma$, radius $R$ and luminosity $L$ of elliptical galaxies are known to be related, leaving only two degrees of freedom and defining the so-called ``fundamental plane". In this {\em Letter} we present observational evidence that rich galaxy clusters exhibit a similar behaviour. Assuming a relati...
1993-04-20
2016-06-08
[ "astro-ph" ]
R. Schaeffer, S. Maurogordato, A. Cappi, F. Bernardeau
astro-ph/9304017
Inflation and Mixed Dark Matter Models
Recent large scale structure observations, including COBE, have prompted many authors to discuss modifications of the standard Cold Dark Matter model. Two of these, a tilted spectrum and a gravitational wave contribution to COBE, are at some level demanded by theory under the usual assumption that inflation generates t...
1993-04-18
2015-06-24
[ "astro-ph", "hep-ph" ]
Andrew R Liddle and David H Lyth
astro-ph/9304015
Indications for Gamma-Ray Bursts Originating within an Extended Galactic Halo ?
If a substantial fraction of the observed gamma-ray bursts originates within an extended Galactic halo then their spatial distribution should deviate slightly from spherical symmetry in a very particular way which involves features both in the bursts' angular and radial distributions. This conclusion is based on vari...
1993-04-16
2007-05-23
[ "astro-ph" ]
Eyal Maoz
astro-ph/9304016
On the Bimodal Distribution of Gamma-Ray Bursts
Kouveliotou et al. (1993) recently confirmed that gamma-ray bursts are bimodal in duration. In this paper we compute the statistical properties of the short ($\le 2$~s) and long ($>2$~s) bursts using a method of analysis that makes no assumption regarding the location of the bursts, whether in the Galaxy or at a cosmol...
1993-04-16
2009-10-22
[ "astro-ph" ]
Shude Mao, Ramesh Narayan and Tsvi Piran
astro-ph/9304014
The First Data from the MACHO Experiment
MAssive Compact Halo Objects such as brown dwarfs, Jupiters, and black holes are prime candidates to comprise the dark halo of our galaxy. Paczynski noted that objects (dubbed MACHOs) with masses in the range $10^{-6}M_\odot < M \simlt 100 M_\odot$. can be detected via gravitational microlensing of stars in the Magella...
1993-04-15
2009-10-22
[ "astro-ph", "hep-ph" ]
D. P. Bennett
astro-ph/9304013
A Green Function for Metric Perturbations due to Cosmological Density Fluctuations
We study scalar perturbations to a Robertson-Walker cosmological metric in terms of a pseudo-Newtonian potential, which emerges naturally from the solution of the field equations. This potential is given in terms of a Green function for matter density fluctuations of arbitrary amplitude whose time and spatial dependenc...
1993-04-14
2009-10-22
[ "astro-ph" ]
Mark W Jacobs, Eric V Linder, and Robert V Wagoner
astro-ph/9304011
Mass Loss In M67 Giants: Evidence From Isochrone Fitting
We present a study of the stellar content of the open cluster M67. We have computed new evolutionary sequences of stellar models with solar abundance that cover all phases of evolution from the Zero-Age Main Sequence to the bright end of the Asymptotic Giant Branch (AGB). We examine the fit between the calculated and t...
1993-04-12
2009-10-22
[ "astro-ph" ]
Michael J. Tripicco, Ben Dorman and Roger A. Bell
astro-ph/9304012
Inflation After COBE: Lectures on Inflationary Cosmology
In these lectures I review the standard hot big-bang cosmology, emphasizing its successes, its shortcomings, and its major challenge---a detailed understanding of the formation of structure in the Universe. I then discuss the motivations for---and the fundamentals of---inflationary cosmology, particularly emphasizing t...
1993-04-12
2007-05-23
[ "astro-ph", "hep-ph" ]
Michael S. Turner
astro-ph/9304010
Errata in Binney and Tremaine, "Galactic Dynamics"
This paper contains all known errata in the book "Galactic Dynamics".
1993-04-10
2007-05-23
[ "astro-ph" ]
J. Binney and S. Tremaine
astro-ph/9304009
The Mass Function of Nearby Galaxy Clusters
We present the distribution of virial masses for nearby galaxy clusters, as obtained from a data-set of 75 clusters, each having at least 20 galaxy members with measured redshifts within 1 Abell radius. After having accounted for problems of incompleteness of the data-set, we fitted a power-law to the cluster mass dist...
1993-04-08
2009-10-22
[ "astro-ph" ]
A. Biviano, M. Girardi, G. Giuricin, F. Mardirossian, and M. Mezzetti
astro-ph/9304008
The 9 Aurigae System
The F0 V star 9 Aur A exhibits an irregular variability of amplitude $\approx $0.1 magnitude at optical wavelengths. The variations are too slow for it to be a $\delta$ Scuti-type star. There is no evidence for a close, interacting companion or ring of dust, either from infrared, ultraviolet, or speckle data. The photo...
1993-04-07
2015-06-24
[ "astro-ph" ]
K. Krisciunas, C. Aspin, T. R. Geballe, H. Akazawa, C. F. Claver, E. F. Guinan, H. J. Landis, K. D. Luedeke, N. Ohkura, O. Ohshima, and D. R. Skillman
astro-ph/9304007
The Neutrino Ball Model of a Quasar
It is suggested that the nonorthodox model of a quasar as a neutrino ball described in terms of the standard model extended by adding right-handed neutrinos and the Majorana scalar field can be presented in order to explain a quasar as a body of weak interacting neutrinos. Neutrino interaction with the scalar Majorana ...
1993-04-07
2019-08-17
[ "astro-ph" ]
R.Manka, I.Bednarek, D.Karczewska
astro-ph/9304005
Element Diffusion in the Solar Interior
We study the diffusion of helium and other heavy elements in the solar interior by solving exactly the set of flow equations developed by Burgers for a multi-component fluid, including the residual heat-flow terms. No approximation is made concerning the relative concentrations and no restriction is placed on the numbe...
1993-04-06
2009-10-22
[ "astro-ph" ]
Anne A. Thoul, John N. Bahcall and Abraham Loeb
astro-ph/9304006
M51 Stripped To Its Bones
We present optical and IR surface photometry of M51 (NGC~5194) at B~V~R~I~J~K and CO$(2.3\mu )$. These data are used to establish whether K-band ($2.2\mu$) images of spiral galaxies provide reliable maps of stellar surface mass density features such as massive spiral arms or bars. The main distorting agents in the mapp...
1993-04-06
2007-05-23
[ "astro-ph" ]
Hans-Walter Rix and Marcia J. Rieke
astro-ph/9304004
Deep Kinematics and Dynamics of Edge-on S0 Galaxies. I. NGC 3115
As a first step of a program aimed to the detection of dark matter (or radial variations of M/L) in early-type galaxies, we report deep spectroscopic observations of the bulge-dominated edge-on S0 galaxy NGC 3115, made at ESO, La Silla, using EFOSC at the 3.6m telescope and EMMI at NTT. Such observations allow measurem...
1993-04-05
2007-05-23
[ "astro-ph" ]
M. Capaccioli, E. Cappellaro, E.V. Held, and M. Vietri
astro-ph/9304002
Higher Order Moments of the Matter Distribution in Scale--Free Cosmological Simulations with Large Dynamic Range
We calculate reduced moments $\overline \xi_q$ of the matter density fluctuations, up to order $q=5$, from counts in cells produced by Particle--Mesh numerical simulations with scale--free Gaussian initial conditions. We use power--law spectra $P(k) \propto k^n$ with indices $n=-3,~-2,~-1,~0,~1$. Due to the supposed ab...
1993-04-02
2009-10-22
[ "astro-ph" ]
F. Lucchin, S. Matarrese, A.L. Melott and L. Moscardini
astro-ph/9304003
Multiwavelength Monitoring of the BL Lac Object PKS 2155-304 I. The IUE Campaign
Daily monitoring of PKS 2155-304 with the IUE satellite throughout November 1991 has revealed dramatic, large-amplitude, rapid variations in the ultraviolet flux of this BL Lac object. Many smaller, rapid flares are superimposed on a general doubling of the intensity. During the five-day period when sampling was roughl...
1993-04-02
2009-10-22
[ "astro-ph" ]
C.M. Urry, et al
astro-ph/9304001
Do Observations Exclude Gamma-ray Bursts Originating In the Oort Cloud Of Comets?
As long as there is no distance indicator to the sources of gamma-ray bursts all possible sources which are isotropically distributed should remain under consideration. This is why the Oort cloud of comets is kept on the list. We use the available data on the bursts' distribution of (the BATSE catalogue), and the Catal...
1993-04-01
2009-10-22
[ "astro-ph" ]
Eyal Maoz
astro-ph/9303019
The Cold Dark Matter Density Perturbation
This is a review of the Cold Dark Matter model of structure formation, and its variants. The approach is largely from first principles, the main aim being to impart a basic understanding of the relevant theory with an eye to the likely intense activity of the next few years, but the current observational status of the ...
1993-03-31
2010-11-30
[ "astro-ph", "gr-qc", "hep-ph" ]
Andrew R Liddle and David H Lyth
astro-ph/9303018
Laser Interferometric Detectors of Gravitational Waves
A laser interferometric detector of gravitational waves is studied and a complete solution (to first order in the metric perturbation) of the coupled Einstein-Maxwell equations with appropriate boundary conditions for the light beams is determined. The phase shift, the light deflection and the rotation of the polarizat...
1993-03-31
2010-04-06
[ "astro-ph" ]
F. I. Cooperstock and V. Faraoni
astro-ph/9303020
Null Geodesics in Perturbed Spacetimes
We present a generalization and refinement of the Sachs-Wolfe technique which unifies many of the approaches taken to date and clarifies both the physical and the mathematical character of the method. We illustrate the formalism with a calculation of the behavior of light passing a moving lens on a Minkowski background...
1993-03-31
2009-10-22
[ "astro-ph", "gr-qc" ]
Ted Pyne and Mark Birkinshaw
astro-ph/9303017
Properties of High-Redshift Lyman Alpha Clouds II. Statistical Properties of the Clouds
Curve of growth analysis, applied to the Lyman series absorption ratios deduced in our previous paper, yields a measurement of the logarithmic slope of distribution of \Lya\ clouds in column density $N$. The observed exponential distribution of the clouds' equivalent widths $W$ is then shown to require a broad distribu...
1993-03-29
2009-10-22
[ "astro-ph" ]
William H. Press and George B. Rybicki
astro-ph/9303016
Properties of High-Redshift Lyman Alpha Clouds I. Statistical Analysis of the SSG Quasars
Techniques for the statistical analysis of the \Lya\ forest in high redshift quasars are developed, and applied to the low resolution (25 \AA) spectra of 29 of the 33 quasars in the Schneider-Schmidt-Gunn (SSG) sample.We find that the mean absorption increases with $z$ approximately as a power law $(1+z)^{\gamma+1}$ wi...
1993-03-29
2009-10-22
[ "astro-ph" ]
William H. Press, George B. Rybicki, and Donald P. Schneider
astro-ph/9303015
Determination of pseudo-Goldstone boson-photon coupling by the differential time delay of pulsar signals
Pseudo-Goldstone bosons couple with photons through a P and T violating interaction of the form ${\cal {L_I}}=g_{a\gamma \gamma}~ a F\tilde F$. Strong magnetic fields in rotating compact stars induce a non-zero ${\vec E}\cdot{\vec B}$ outside the stellar surface which acts as a source for the pseudo-scalar field. Pulsa...
1993-03-27
2009-10-22
[ "astro-ph" ]
Subhendra Mohanty and S.N.Nayak
astro-ph/9303014
The Imprint of Gravitational Waves on the Cosmic Microwave Background
Long-wavelength gravitational waves can induce significant temperature anisotropy in the cosmic microwave background. Distinguishing this from anisotropy induced by energy density fluctuations is critical for testing inflationary cosmology and theories of large-scale structure formation. We describe full radiative tran...
1993-03-26
2009-09-25
[ "astro-ph", "hep-ph" ]
R. Crittenden, J.R. Bond, R.L. Davis, G. Efstathiou, P.J. Steinhardt
astro-ph/9303013
Cosmic Rays, III. The CR spectrum between 1 GeV and 10^4 GeV and the radio emission from supernova remnants
We develop a theory to account for the cosmic ray spectrum between 1 GeV and 10^4 GeV following the earlier papers of this series. We use the basic concept that the cosmic ray particles are accelerated in a supernova shock that travels through the interstellar medium. Physically important ingredients besides the presen...
1993-03-25
2007-05-23
[ "astro-ph" ]
Peter L. Biermann (1) and Richard G. Strom (2) ((1) Max-Planck-Institut f"ur Radioastronomie, Bonn, Germany, (2) Netherlands Foundation for Research in Astronomy, Radiosterrenwacht, Dwingeloo, Netherlands)
astro-ph/9303012
Dynamics with a non-standard inertia-acceleration relation: an alternative to dark matter
We investigate particle laws of motion derived from nonstandard kinetic actions of a special form. We are guided by a phenomenological scheme--the modified dynamics (MOND)--that imputes the mass discrepancy observed in galactic systems to a departure from Newtonian dynamics below a certain acceleration scale a0. In the...
1993-03-23
2008-11-26
[ "astro-ph", "gr-qc" ]
M. Milgrom
astro-ph/9303011
Perturbation Spectra from Intermediate Inflation
We investigate models of `intermediate' inflation, where the scale factor $a(t)$ grows as $a(t) = \exp (A t^f)$, $0 < f < 1$, $A$ constant. These solutions arise as exact analytic solutions for a given class of potentials for the inflaton $\phi$. For a simpler class of potentials falling off as a power of $\phi$ they a...
1993-03-23
2009-12-30
[ "astro-ph" ]
John D Barrow and Andrew R Liddle
astro-ph/9303010
Approximate Self-Consistent Models for Tidally Truncated Star Clusters
This paper generalises King's models for tidally truncated star clusters by including approximately the non-spherical symmetry of the tidal field and the resulting non-spherical distortion of the cluster.
1993-03-19
2007-05-23
[ "astro-ph" ]
D.C. Heggie & N. Ramamani
astro-ph/9303009
Cosmic Variance in CMB Anisotropies: From $1^{\circ}$ to COBE
Cosmic Microwave Background (CMB) anisotropies that result from quantum fluctuations during inflation are explored and the impact of their ``cosmic variance'' on the ability to use existing data to probe inflationary models is studied. We calculate the rms temperature fluctuation, and its cosmic variance, for a number ...
1993-03-19
2016-08-30
[ "astro-ph", "hep-ph" ]
Martin White, Lawrence M. Krauss and Joseph Silk
astro-ph/9303008
Threshold Star Formation Effects in the Peculiar Galaxy Arp~10 (=~VV 362)
We present images of the peculiar galaxy Arp~10 which reveal two rings of concurrent star formation. Apart from a bright ring visible on early photographs of the system, an even brighter inner ring of \ion{H}{2} regions is found within the nuclear bulge of the galaxy. A very faint ring-arc of \ion{H}{2} regions is also...
1993-03-17
2014-10-13
[ "astro-ph" ]
V. Charmandaris, P. N. Appleton, and A. P. Marston
astro-ph/9303007
The Local Galaxy Density and the Bars of Spiral Galaxies
Using a variety of parameters of local galaxy density, we have examined the effects of the environmental density on the presence of bar structures in spiral galaxies of various morphological types. For an extensive sample of nearby galaxies, listed in the ``Nearby Galaxies Catalogue'' (Tully, 1988a), we have found that...
1993-03-15
2009-10-22
[ "astro-ph" ]
G. Giuricin, F. Mardirossian, M. Mezzetti, P. Monaco
astro-ph/9303006
Cosmic Rays IV. The spectrum and chemical composition above $10^4$ GeV
Using the concept developed in earlier papers, that the cosmic rays originate in three different main sites, a) the normal supernova explosions into the interstellar medium, b) the supernova explosions into a stellar wind, and c) powerful radio galaxies, we demonstrate in this paper that the spectrum and chemical abund...
1993-03-11
2007-05-23
[ "astro-ph" ]
T. Stanev, P.L. Biermann, T.K. Gaisser
astro-ph/9303005
A Semi-Analytical Analysis of Texture Collapse
This study presents a simplified approach to studying the dynamics of global texture collapse. We derive equations of motion for a spherically symmetric field configuration using a two parameter ansatz. Then we analyse the effective potential for the resulting theory to understand possible trajectories of the field con...
1993-03-10
2010-11-19
[ "astro-ph", "hep-ph" ]
Andrew T. Sornborger (Brown)
astro-ph/9303004
Early Cosmic Formation of Massive Black Holes
The evolution of nonlinear density fluctuations around the Jeans mass shortly after cosmological recombination is analyzed using a 3D hydrodynamics/dark--matter code. The Cosmic Background Radiation (CBR) exerts Compton friction on free electrons due to peculiar velocities. The dynamics therefore depends strongly on th...
1993-03-09
2009-10-22
[ "astro-ph" ]
M. Umemura, A. Loeb, and E. L. Turner
astro-ph/9303003
Blue Stragglers as Tracers of Globular Cluster Evolution
Blue stragglers are natural phenomena in star clusters. They originate through mass transfer in isolated binaries, as well as through encounters between two or more stars, in a complex interplay between stellar dynamics and stellar evolution. While this interplay cannot be modeled quantitatively at present, we will be ...
1993-03-08
2007-05-23
[ "astro-ph", "hep-lat" ]
Piet Hut
astro-ph/9303002
The Masses of Two Binary Neutron Star Systems
The measurement or constraint of the masses of neutron stars and their binary companions tests theories of neutron star structure and of pulsar formation and evolution. We have measured the rate of the general relativistic advance of the longitude of periastron for the pulsar PSR B1802$-$07: $\dot\omega=0\fdg060\pm0\fd...
1993-03-02
2009-10-22
[ "astro-ph" ]
S. E. Thorsett (Caltech), Z. Arzoumanian (Princeton), M. M. McKinnon (NRAO), and J. H. Taylor (Princeton)
astro-ph/9303001
Inflation and squeezed quantum states
The inflationary cosmology is analyzed from the point of view of squeezed quantum states. As noted by Grishchuk and Sidorov, the amplification of quantum fluctuations into macroscopic perturbations which occurs during cosmic inflation is a process of quantum squeezing. We carefully develop the squeezed state formalism ...
1993-03-01
2010-04-08
[ "astro-ph", "gr-qc", "hep-ph" ]
Andreas Albrecht, Pedro Ferreira, Michael Joyce and Tomislav Prokopec
astro-ph/9302018
Constraints on the Cosmic Rays in the Small Magellanic Cloud
We show that recent $\gamma$-ray observations of the Small Magellanic Cloud with EGRET rule out a universal cosmic ray flux only at energies below $\approx 10$ GeV, while the observed diffuse X-ray and $\gamma$-ray background radiations have already ruled out, by more than three orders of magnitude, a universal extraga...
1993-02-25
2009-10-22
[ "astro-ph" ]
Arnon Dar, Ari Laor, and Abraham Loeb
astro-ph/9302017
The Rate of Supernovae. II. the Selection Effects and the Frequencies Per Unit Blue Luminosity
We present new estimates of the observed rates of SNe determined with the {\em control time} method applied to the files of observations of two long term, photographic SN searches carried out at the Asiago and Sternberg Observatories. Our calculations are applied to a galaxy sample extracted from RC3, in which 65 SNe h...
1993-02-25
2007-05-23
[ "astro-ph" ]
E. Cappellaro, M. Turatto, Benetti, D.Yu. Tsvetkov, O.S. Bartunov and I.N. Makarova
astro-ph/9302016
Angular Distribution of Clustersin Skewed CDM Models
We perform a detailed investigation of the statistical properties of the projected distribution of galaxy clusters obtained in Cold Dark Matter (CDM) models with both Gaussian and skewed primordial density fluctuations. We use N-body simulations to construct a set artificial Lick maps. An objective cluster--finding alg...
1993-02-24
2015-06-24
[ "astro-ph" ]
S.Borgani, P.Coles, L.Moscardini & M.Plionis
astro-ph/9302015
Skewness as a Test of Non-Gaussian Primordial Density Fluctuations
We investigate the evolution of the skewness of the distribution of density fluctuations in CDM models with both Gaussian and non--Gaussian initial fluctuations. We show that the method proposed by Coles \& Frenk (1991), which uses the skewness of galaxy counts to test the hypothesis of Gaussian primordial density fluc...
1993-02-24
2015-06-24
[ "astro-ph" ]
P. Coles, L. Moscardini, F. Lucchin, S. Matarrese, A. Messina
astro-ph/9302014
Angular Correlations of the X-Ray Background and Clustering of Extragalactic X-Ray Sources
The information content of the autocorrelation function (ACF) of intensity fluctuations of the X-ray background (XRB) is analyzed. The tight upper limits set by ROSAT deep survey data on the ACF at arcmin scales imply strong constraints on clustering properties of X-ray sources at cosmological distances and on their co...
1993-02-24
2009-10-22
[ "astro-ph" ]
L. Danese, L. Toffolatti, A. Franceschini, J.M. Martin-Mirones and G. De Zotti
astro-ph/9302013
On the Production of Scalar and Tensor Perturbations in Inflationary Models
The amplitude and spectrum of the scalar and tensor perturbations depend upon the shape of the inflationary potential in the small interval where the scalar field responsible for inflation was between about 46 and 54 e-folds before the end of inflation. By expanding the inflationary potential in a Taylor series in this...
1993-02-23
2008-11-26
[ "astro-ph", "hep-ph" ]
M.S. Turner
astro-ph/9302012
Large--Scale Angular Correlations in CDM Models
We generate artificial Lick maps using $N$--body simulations and compare the angular correlation function, $w(\vartheta)$, measured from the simulations with the APM correlation. For the Gaussian CDM model, neither the standard biassed model nor a more evolved model (as suggested by the COBE data), reproduce the correl...
1993-02-23
2009-10-22
[ "astro-ph" ]
L.Moscardini, S.Borgani, P.Coles, F.Lucchin, S.Matarrese and A.Messina
astro-ph/9302011
The 8-13 Micron Spectrum of Arp 299C
Arp 299C is a $5 \times 10^{10}$ \Lsun infrared source in the merging galaxy system Arp 299. It is the most luminous object known that is not obviously associated with a galaxy nucleus. Our data show that the 8--13 \mum spectrum of Arp 299C has a strong \NeII emission line and emission features like those of polycyclic...
1993-02-19
2009-10-22
[ "astro-ph" ]
C. C. Dudley and C. G. Wynn-Williams
astro-ph/9302010
The End for Extended Inflation?
This paper is based on a talk given by A R Liddle at the PASCOS/TEXAS meeting in December 1992, and will appear in the proceedings. The central result is that all known models of inflation which end in a first order phase transition can be ruled out by combining galaxy surveys at a few tens of Mpc with the COBE data (i...
1993-02-18
2009-10-22
[ "astro-ph", "gr-qc", "hep-ph" ]
A R Liddle and D H Lyth
astro-ph/9302009
Biasing and Hierarchical Statistics in Large-scale Structure
In the current paradigm there is a non-trivial bias expected in the process of galaxy formation. Thus, the observed statistical properties of the galaxy distribution do not necessarily extend to the underlying matter distribution. Gravitational evolution of initially Gaussian seed fluctuations predicts that the connect...
1993-02-15
2009-10-22
[ "astro-ph" ]
J.N.Fry and Enrique Gaztanaga
astro-ph/9302008
Gamma Ray Bursts and CETI
Gamma ray burst sources are isotropically distributed. They could be located at distances $\sim 1000$ AU. (Katz \cite{JK92}) GRB signals have many narrow peaks that are unresolved at the millisecond time resolution of existing observations. \cite{JK87} CETI could use stars as gravitational lenses for interstellar gamma...
1993-02-10
2007-05-23
[ "astro-ph" ]
Frank D. Smith Jr
astro-ph/9302007
The Least Action Principle And The Spin Of Galaxies In The Local Group
Using Peebles' least action principle, we determine trajectories for the galaxies in the Local Group and the more massive galaxies in the Local Neighbourhood. We deduce the resulting angular momentum for the whole of the Local Group and study the tidal force acting on the Local Group and its galaxies. Although Andromed...
1993-02-10
2015-06-24
[ "astro-ph" ]
A.M.Dunn and R.Laflamme
astro-ph/9302006
The Proton Blazar
Considering shock-accelerated protons in addition to electrons in a synchrotron radio jet naturally produces the observed X- through gamma ray continuum emission of flat-spectrum radio-loud AGN, whereas the corresponding shock-accelerated electrons produce the infrared through optical continuum. All of these emission c...
1993-02-04
2008-02-03
[ "astro-ph", "hep-ph" ]
Karl Mannheim
astro-ph/9302004
Background Radiation
We present a short overview on the extragalactic background radiation from radio to X-rays, with an eye to the relation to galaxy formation and emphasizing on astrophysical backgrounds (as opposed to cosmological). As the radio background, the wealth of data on source counts make possible reliable estimations of the co...
1993-02-04
2007-05-23
[ "astro-ph" ]
G. De Zotti, A. Franceschini, L. Toffolatti, P. Mazzei and L. Danese
astro-ph/9302005
Extragalactic ultra high energy cosmic rays, II. Comparison with experimental data
We compare the expected contribution of FR-II hot spots to the ultra-high energy cosmic ray spectrum (Rachen & Biermann 1993, A&A in press, BB paper astro-ph/9301010) to improved experimental results. We introduce a "world data set" of UHE cosmic rays by comparing the data of various experiments, extracting relative sy...
1993-02-04
2011-05-12
[ "astro-ph" ]
Joerg P. Rachen(1), Todor Stanev(2) and Peter L. Biermann(1) ((1) Max-Planck-Institut f"ur Radiostronomie, Bonn, Germany; (2) Bartol Research Institute, Newark DE, USA)
astro-ph/9302003
Dark Matter: Theoretical Perspectives
Talk presented at NAS Special Colloquium on Physical Cosmology
1993-02-04
2015-06-24
[ "astro-ph", "hep-ph" ]
M.S. Turner
astro-ph/9302002
Dynamical Solutions to the Horizon and Flatness Problems
We discuss in some detail the requirements on an early-Universe model that solves the horizon and flatness problems during the epoch of classical cosmology ($t\ge t_i\gg 10^{-43}\sec$). We show that a dynamical resolution of the horizon problem requires superluminal expansion (or very close to it) and that a truly sati...
1993-02-03
2009-12-30
[ "astro-ph", "hep-ph" ]
Yue Hu, Michael S. Turner, and Erick J. Weinberg
astro-ph/9302001
Angular Momentum Loss in Low Mass Accretion Disks
We review mechanisms for the transport of angular momentum in accretion disks that are low mass, in the sense that the gravitational forces produced by the material in these disks has a negligible effect on disk dynamics. There is no established consensus on how this transport takes place. We note that for phenomenolog...
1993-02-03
2007-05-23
[ "astro-ph" ]
ET Vishniac and PH Diamond
astro-ph/9301012
A Possible Forest of Emission Lines from Proto-galaxies
The possibility of detecting proto-galaxies in the UV band is pointed out, assuming that galaxy formation occured at z $\sim 5-6$. It is shown that the diffuse gas in collapsing galaxy sized objects with temperatures $\sim 10^{6\pm0.5}$ K, and with a modest amount of metallicity, should copiously produce emission lines...
1993-01-29
2016-06-08
[ "astro-ph" ]
Biman Nath and David Eichler
astro-ph/9301010
Extragalactic ultra high energy cosmic rays, I. Contribution from hot spots in FR-II galaxies
We consider the hot spots in FR-II galaxies as sites of first order Fermi acceleration of protons to the highest energies observed in cosmic rays. We estimate the attainable maximum energy in the hot spot region allowed by the canonical physical conditions, which are found from radio-to-optical observations (Meisenheim...
1993-01-21
2011-05-23
[ "astro-ph" ]
Joerg P. Rachen and Peter L. Biermann (Max-Planck-Institut fuer Radioastronomie, Bonn, Germany)
astro-ph/9301011
Minimal Microwave Anisotropy from Perturbations Induced at Late Times
Aside from primordial gravitational instability of the cosmological fluid, various mechanisms have been proposed to generate large-scale structure at relatively late times, including, e.g., ``late-time'' cosmological phase transitions. In these scenarios, it is envisioned that the universe is nearly homogeneous at the ...
1993-01-21
2009-10-22
[ "astro-ph" ]
Andrew H. Jaffe, Albert Stebbins, and Joshua A. Frieman
astro-ph/9301009
Extended Co(7-6) Emission from Warm Gas in Orion
We mapped quiescent 807 GHz CO(7-6) emission from Orion along a strip in RA extending from 0.7 pc west to 1.2 pc east of Ori theta 1C. The lines arise in warm gas with T > 40 K. The line brightness temperature is > 160 K in the di- rection of theta 1C, more than twice the dust temperature, and still exceeds 35 K more t...
1993-01-18
2009-10-22
[ "astro-ph" ]
J.E. Howe, D.T. Jaffe, E.N. Grossman, W.F. Wall, J.G. Mangum, and G.J. Stacey
astro-ph/9301008
Cosmic Rays I.: The cosmic ray spectrum between 10 TeV and 3 EeV
I develop a theory to account for the cosmic ray spectrum. The essential assumption is that, due to fast convective motions, the free mean path perpendicular to the magnetic field is independent of energy and has the scale of the thickness of the shocked layer. I use the basic concept, that the energetic Cosmic Ray par...
1993-01-15
2007-05-23
[ "astro-ph" ]
Peter L. Biermann (Max Planck Institut fuer Radioastronomie, Bonn, Germany)
astro-ph/9301006
The Evolution of the Globular Cluster System in a Triaxial Galaxy: Can a Galactic Nucleus Form by Globular Cluster Capture?
Dynamical friction due to field stars and tidal disruption caused by a central nucleus are crucial in determining the evolution of the globular cluster system in an elliptical galaxy. In this paper I examine the possibility that some of galactic nuclei have been formed by frictionally decayied globular clusters moving ...
1993-01-14
2009-10-22
[ "astro-ph" ]
R. Capuzzo-Dolcetta
astro-ph/9301007
Gasdynamics of Relativistically Expanding Gamma-Ray Burst Sources: Kinematics, Energetics, Magnetic Fields and Efficiency
We calculate both analytically and numerically the evolution of a highly relativistic fireball through the stages of free expansion and coasting, and determine the dependence of the thermodynamic and radiation variables in the comoving and laboratory frames. Magnetic fields may have been important in the original impul...
1993-01-14
2009-10-22
[ "astro-ph" ]
P. M\'esz\'aros, P. Laguna and M.J. Rees
astro-ph/9301005
Constraints on Dirac Neutrinos from SN 1987A
The Livermore Supernova Explosion Code was used to calculate the effect of a massive Dirac neutrino on neutrino emission from SN 1987A in a fully self-consistent manner. Spin-flip interactions lead to the copious emission of sterile, right-handed neutrinos and cool the core faster than the observed neutrino emission ti...
1993-01-13
2009-10-22
[ "astro-ph", "hep-ph" ]
R. Mayle, D.N. Schramm, M.S. Turner, J. Wilson
astro-ph/9301004
Hydrodynamics of Relativistic Fireballs
We examine analytically and numerically the evolution of a relativistic fireball. We show that, after an early rearrangement phase, most of the matter and energy in the fireball is concentrated within a narrow shell. The shell propagates at nearly the speed of light, with a frozen radial profile and according to a simp...
1993-01-12
2015-06-24
[ "astro-ph" ]
Tsvi Piran, Amotz Shemi and Ramesh Narayan
astro-ph/9301003
Similarity of the variability patterns in the Exosat and Ginga folded light curves of the Seyfert galaxy NGC 6814
The Seyfert galaxy NGC 6814 is known to show periodic variation of its X-ray luminosity. We found that the sequences of peaks (variability patterns) in the folded X-ray light curves constructed from the {\it Exosat} and {\it Ginga} data are remarkably similar when one ignores amplitudes of the peaks and considers only ...
1993-01-08
2007-05-23
[ "astro-ph" ]
M.A. Abramowicz, G. Bao, V. Karas and A. Lanza
astro-ph/9301001
The Peculiar Balmer Line Profiles of OQ 208
We present spectrophotometric observations of the Broad Line Radio Galaxy OQ 208 (Mrk 668, 1404+286) obtained between 1985 and 1991. We show that the Balmer line fluxes and profile shapes undergo remarkable changes. The ratio of intensities between the broad and narrow components of Hbeta increased monotonically from 1...
1993-01-07
2009-10-22
[ "astro-ph" ]
P. Marziani, J.W. Sulentic, M. Calvani, E. Perez, M. Moles, & M. V. Penston
astro-ph/9301002
Microwave Anisotropies in the Light of COBE
The recent COBE measurement of anisotropies in the cosmic microwave background and the recent South Pole experiment of Gaier {\it et al.} offer an excellent opportunity to probe cosmological theories. We test a class of theories in which the Universe today is flat and matter dominated, and primordial perturbations are ...
1993-01-07
2009-10-22
[ "astro-ph", "hep-ph" ]
Scott Dodelson and Jay M. Jubas
chao-dyn/9312008
The Dynamics Of Vortex Structures And States Of Current In Plasma-Like Fluids And The Electrical Explosion Of Conductors: 1. The model of a non-equilibrium phase transition
A set of equations according to which the conducting medium consists of two fluids - laminar and vortex, has been obtained in the present paper by transforming MHD equations. In a similar way, an electronic fluid is assumed to consist of a laminar and a vortex fluid. This system allows one to study the formation and th...
1993-12-21
2009-10-22
[ "chao-dyn", "nlin.CD" ]
N.B. Volkov and A.M. Iskoldsky (Russian Academy of Science, Ural Division, Institute of Electrophysics, 34, Komsomolskaya St., Ekaterinburg, 620219, Russia)
chao-dyn/9312007
Bifurcations and Spatial Chaos in an Open Flow Model
It is shown that a coupled map model for open flow may exhibit spatial chaos and spatial quasiperiodicity with temporal periodicity. The locations of these patterns, which cover a substantial part of parameter space, are indicated in a comprehensive phase diagram. In order to analyze the encountered phenomena, a novel ...
1993-12-21
2009-10-22
[ "chao-dyn", "nlin.CD" ]
Frederick H. Willeboordse (University of Tokyo), Kunihiko Kaneko (University of Tokyo)
chao-dyn/9312006
The Limits of Mathematics---Course Outline and Software
A remarkable new definition of a self-delimiting universal Turing machine is presented that is easy to program and runs very quickly. This provides a new foundation for algorithmic information theory. This new universal Turing machine is implemented via software written in Mathematica and C. Using this new software, it...
1993-12-12
2008-02-03
[ "chao-dyn", "adap-org", "nlin.AO", "nlin.CD" ]
G. J. Chaitin (IBM Research Division)
chao-dyn/9312005
Noise-Induced Linearisation and Delinearisation
It is demonstrated, by means of analogue electronic simulation and theoretically, that external noise can markedly change the character of the response of a nonlinear system to a low-frequency periodic field. In general, noise of sufficient intensity {\it linearises} the response. For certain parameter ranges in partic...
1993-12-09
2008-02-03
[ "chao-dyn", "adap-org", "nlin.AO", "nlin.CD" ]
MI Dykman, DG Luchinsky, R Mannella, PVE McClintock, HE Short, ND Stein and N G Stocks
chao-dyn/9312004
Self-Similarity of Friction Laws
The change of the friction law from a mesoscopic level to a macroscopic level is studied in the spring-block models introduced by Burridge-Knopoff. We find that the Coulomb law is always scale invariant. Other proposed scaling laws are only invariant under certain conditions.}
1993-12-06
2009-10-22
[ "chao-dyn", "nlin.CD" ]
Maria de Sousa Vieira and Hans J. Herrmann
chao-dyn/9312003
Transport Properties of the Lorentz Gas in Terms of Periodic Orbits
We establish a formula relating global diffusion in a space periodic dynamical system to cycles in the elementary cell which tiles the space under translations.
1993-12-05
2008-02-03
[ "chao-dyn", "nlin.CD" ]
P. Cvitanovi\'c (Niels Bohr Institute, Blegdamsvej 17, DK-2100 Copenhagen \O, Denmark), J.-P. Eckmann (D\'epartement de Physique Th\'eorique, Universit\'e de Gen\`eve, CH-1211 Geneva 4, Switzerland), P. Gaspard (Service de Chimie-Physique, Universit\'e Libre de Bruxelles, Campus Plaine, B-1050 Brussels, Belgium...
chao-dyn/9312001
Universality in fully developed turbulence
We extend the numerical simulations of She et al. [Phys.\ Rev.\ Lett.\ 70, 3251 (1993)] of highly turbulent flow with $15 \le$ Taylor-Reynolds number $Re_\lambda\le 200$ up to $Re_\lambda \approx 45000$, employing a reduced wave vector set method (introduced earlier) to approximately solve the Navier-Stokes equation. F...
1993-12-03
2009-10-22
[ "chao-dyn", "nlin.CD" ]
Siegfried Grossmann (1) and Detlef Lohse (2) ((1) Fachbereich Physik, Philipps-Universit''at, Marburg, Germany (2) The James Franck Institute, The University of Chicago, Chicago, IL)
chao-dyn/9312002
Effect of a magnetic flux line on the quantum beats in the H\'enon-Heiles level density
The quantum density of states of the H\'enon-Heiles potential displays a pronounced beating pattern. This has been explained by the interference of three isolated classical periodic orbits with nearby actions and periods. A singular magnetic flux line, passing through the origin, drastically alters the beats even thoug...
1993-12-03
2008-02-03
[ "chao-dyn", "nlin.CD" ]
M. Brack(1), R. K. Bhaduri(2), J. Law(3), Ch. Maier(1), and M. V. N. Murthy ((1)Institute for Theoretical Physics, University of Regensburg, D-93040 Regensburg, Germany. (2)Department of Physics and Astronomy, McMaster University, Hamilton, Canada L8S 4M1. (3)Department of Physics, University of Guelph, Guelph,...
chao-dyn/9311011
The Great Inequality In A Hamiltonian Planetary Theory
The Jupiter-Saturn 2:5 near-commensurability is analyzed in a fully analytic Hamiltonian planetary theory. Computations for the Sun-Jupiter-Saturn system, extending to the third order of the masses and to the 8th degree in the eccentricities and inclinations, reveal an unexpectedly sensitive dependence of the solution ...
1993-11-30
2012-08-27
[ "chao-dyn", "nlin.CD" ]
F. Varadi, M. Ghil and W. M. Kaula (Institute of Geophysics and Planetary Physics University of California, Los Angeles Los Angeles,CA) Keywords: Hamiltonian systems, planetary motion, perturbation theory, resonances