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astro-ph/9509149
Baryonic Dark Halos: Machos and Cold Gas?
We consider the possibility that the dark matter in the halos of galaxies may be in the form of clusters of \macho s within which are embedded cold, dense gas clouds. Microlensing experiments have found evidence that the Galactic halo contains up to half of its mass in the form of low-mass \macho s. A number of observa...
1995-09-29
2009-10-28
[ "astro-ph" ]
Ortwin Gerhard (Astron.Inst., Univ.Basel, CH) and Joseph Silk (Dpt.Astron.&Phys., Univ.Calif., Berkeley, USA)
astro-ph/9509152
On the Validity of the Classical Apsidal Motion Formula for Tidal Distortion
We check the validity of the widely used classical apsidal motion formula as a function of orbital parameters, stellar structure, and stellar rotation rate by comparing dynamical calculations of the periastron advance with the static tidal formula. We find that the classical formula gives very accurate results when the...
1995-09-29
2016-08-30
[ "astro-ph" ]
Eliot Quataert, Pawan Kumar, and Chi On Ao (MIT)
astro-ph/9509151
High-Latitude Galactic Emission in the COBE DMR Two-Year Sky Maps
We cross-correlate the COBE-DMR 2-year sky maps with spatial templates from long-wavelength radio surveys and the far-infrared COBE DIRBE maps. We place an upper limit on the spectral index of synchrotron radiation beta_{synch} < -2.9 between 408 MHz and 31.5 GHz. We obtain a statistically significant cross-correlation...
1995-09-29
2007-05-23
[ "astro-ph" ]
A. Kogut, A.J. Banday, C.L. Bennett, K.M. Gorski, G. Hinshaw, and W.T. Reach
astro-ph/9509148
The Baryon Fraction and Velocity--Temperature Relation in Galaxy Clusters : Models versus Observations
The observed baryon fraction and velocity--temperature relation in clusters of galaxies are compared with hydrodynamic simulations in two cosmological models : standard (Omega = 1) and a low-density flat (Omega=0.45 and \lambda=0.55) CDM models, normalized to the COBE background fluctuations. The observed properties of...
1995-09-28
2009-10-28
[ "astro-ph" ]
Lori M. Lubin, Renyue Cen, Neta A. Bahcall & Jeremiah P. Ostriker (Princeton University Observatory)
astro-ph/9509147
Cold + Hot Dark Matter and the Cosmic Microwave Background
We examine the cosmic microwave background power spectrum for adiabatic models with a massive neutrino component. We present the results of a detailed numerical evolution of cold + hot dark matter (CHDM) models and compare with the standard cold dark matter (CDM) spectrum. The difference is of order $5-10%$ for $400 < ...
1995-09-28
2009-10-28
[ "astro-ph" ]
Scott Dodelson, Evalyn Gates, Albert Stebbins
astro-ph/9509145
Mixed Dark Matter Model in Halos of Clusters
We discuss the structure of clusters in a class of flat cosmological models with the fraction of mass \Omega_{CDM} ~0.8 in cold dark matter, and the rest in hot dark matter in the form of massive neutrinos. We consider such Cold+Hot Dark Matter (CHDM) models with one, two or three massive neutrinos, with total mass ~4....
1995-09-28
2009-10-28
[ "astro-ph", "gr-qc", "hep-ph" ]
Lev Kofman, Anatoly Klypin, Dmitri Pogosyan and J.Patrick Henry
astro-ph/9509146
Observationnal constraints on the nature of the low redshift Lyman-alpha absorbers
We present results from a spectroscopic and imaging survey of galaxies in the fields of quasars from the HST Quasar Absorption Line Key Project. The aim of this survey is to identify galaxies within 3.5' from the quasar sightline, to a limiting r-band magnitude mr = 22.5. The data are then compared to the HST homogeneo...
1995-09-28
2007-05-23
[ "astro-ph" ]
V. Le Brun (Institut d'Astrophysique de Paris), J. Bergeron (E.S.O., I.A.P.), P. Boisse (Ecole Normale Superieure de Paris)
astro-ph/9509144
The Dynamics and Outcomes of Rapid Infall onto Neutron Stars
We present an extensive study of accretion onto neutron stars in which the velocity of the neutron star and structure of the surrounding medium is such that the Bondi-Hoyle accretion exceeds .001 Msun/y. For most cases, hypercritical accretion due to rapid neutrino cooling allows the neutron star to accrete above the B...
1995-09-27
2016-08-30
[ "astro-ph" ]
Chris L. Fryer, Willy Benz (Steward Observatory), and Marc Herant(LANL)
astro-ph/9509140
Advection-Dominated Accretion Model of Sagittarius A$^*$ and Other Accreting Black Holes
Viscous rotating accretion flows around black holes become advection-dominated when the accretion rate $\dot M$ is sufficiently low. Most of the accretion energy in such flows is stored within the gas and advected radially inward. The temperature is therefore very high, and much of the radiation comes out in hard X-ray...
1995-09-27
2011-05-23
[ "astro-ph" ]
Ramesh Narayan, Insu Yi, and Rohan Mahadevan
astro-ph/9509138
Cyclo-Synchrotron Emission and Comptonization in Optically Thin Hot Accretion Flows
Soft cyclo-synchrotron photons produced by thermal electrons moving in a magnetic field can be subsequently Comptonized to produce hard X-ray and $\gamma$-ray emission. An accurate determination of the amount of soft cyclo-synchrotron photons produced from such plasmas is clearly necessary. We present the complete solu...
1995-09-27
2007-05-23
[ "astro-ph" ]
Rohan Mahadevan
astro-ph/9509143
Galaxy Dynamics Predictions in the Nonsymmetric Gravitational Theory
In the weak field approximation, the nonsymmetric gravitational theory (NGT) has, in addition to the Newtonian gravitational potential, a Yukawa-like potential produced by the exchange of a spin $1^+$ boson between fermions. If the range $r_0=\mu^{-1}$ is $25$ kpc, then this additional potential due to the interaction ...
1995-09-27
2010-11-30
[ "astro-ph", "gr-qc" ]
J. W. Moffat and I. Yu. Sokolov
astro-ph/9509133
Application of Millisecond Pulsar Timing to the Long-Term Stability of Clock Ensembles
Terrestrial timescales show instabilities due to the physical limitations of the atomic clocks. Stricter environmental isolation and increased numbers of improved cesium clocks and cavity-tuned hydrogen masers have resulted in time scales more accurate by a factor of about five. The use of different clock ensembles res...
1995-09-27
2007-05-23
[ "astro-ph" ]
Demetrios N. Matsakis, Roger S. Foster
astro-ph/9509136
Cosmic Metal Production and the Contribution of QSO Absorption Systems to the Ionizing Background
The recent discovery by Cowie \etal and Tytler \etal of metals in the \Lya clouds shows that the intergalactic medium (IGM) at high redshift is contaminated by the products of stars, and suggests that ionizing photons from massive star formation may be a significant contributor to the UV background radiation at early e...
1995-09-27
2009-10-28
[ "astro-ph" ]
Piero Madau and J. Michael Shull
astro-ph/9509137
Consequences of Dust in Metal-Rich HII Regions
Dust and associated depletion of heavy elements from the gas phase can modify the thermal properties of HII regions from the dust-free case, with significant consequences for the emergent optical spectrum. We present the results of theoretical calculations illustrating the effects of grains on the spectra of giant, ext...
1995-09-27
2009-10-28
[ "astro-ph" ]
Joseph C. Shields, Robert C. Kennicutt (Steward Observatory)
astro-ph/9509141
The Phase Space Structure Near Neptune Resonances in the Kuiper Belt
The Solar system beyond Neptune is believed to house a population of small primordial bodies left over from the planet formation process. The region up to heliocentric distance $\sim 50 AU$ (a.k.a. the Kuiper Belt) may be the source of the observed short period comets. In this region, the phase space structure near orb...
1995-09-27
2009-10-28
[ "astro-ph" ]
Renu Malhotra (Lunar and Planetary Institute)
astro-ph/9509142
The 1979, March 5 Gamma-Ray Transient: Was it a Classic Gamma-Ray Burst?
The March 5th, 1979 gamma-ray transient has long been thought to be fundamentally different from the classic gamma-ray bursts (GRBs). It had recurrences, pulsations, and a soft spectral component unlike classic GRBs. With the exception of the soft component reported from the Konus experiment, the unusual characteristic...
1995-09-27
2009-10-28
[ "astro-ph" ]
E.E. Fenimore, R.W. Klebesadel, and J.G. Laros (Los Alamos National Laboratory)
astro-ph/9509139
Models of Quiescent Black Hole Neutron Star Soft X-Ray Transients
When the mass accretion rate onto a black hole (BH) falls below a critical rate, ${\dot M}_{crit}\sim \alpha^2 {\dot M}_{Edd}$, accretion can occur via a hot optically thin flow where most of the dissipated energy is advected inward. We present such an advection-dominated model for the soft X-ray transient (SXT) A0620-...
1995-09-27
2011-05-23
[ "astro-ph" ]
Insu Yi, Ramesh Narayan, Didier Barret, & Jeffrey E. McClintock
astro-ph/9509130
Spectrum of the Supernova Relic Neutrino Background and Evolution of Galaxies
The spectrum of the supernova relic neutrino background (SRN) from collapse-driven supernovae ever occurred in the universe is calculated by using a realistic, time-dependent supernova rate derived from a standard model of galaxy evolution based on the population synthesis method. The SRN spectrum we show here is the m...
1995-09-26
2010-11-30
[ "astro-ph" ]
Tomonori Totani, Katsuhiko Sato, and Yuzuru Yoshii (the University of Tokyo)
astro-ph/9509135
Does the Crab Have a Shell?
We present deep images of a region around the Crab nebula made with the VLA, utilizing new imaging and deconvolution algorithms in a search for a faint radio shell. The existence of a high-velocity, hydrogen-rich envelope has been predicted to account for the low total mass and kinetic energy of the observed nebula. No...
1995-09-26
2009-10-28
[ "astro-ph" ]
D.A. Frail, N.E. Kassim, T.J. Cornwell and W.M. Goss
astro-ph/9509134
Differential neutrino heating and reduced $^4$He production from decaying particles in the early universe
A decaying particle that dominates the energy density of the universe and then decays with a lifetime $\sim 10^{-1}$ sec into electromagnetically-interacting particles can heat the background electron neutrinos more than the $\mu$ and $\tau$ neutrinos, resulting in a decrease in the primordial $^4$He abundance. Previou...
1995-09-26
2007-05-23
[ "astro-ph" ]
Richard E. Leonard and Robert J. Scherrer (Ohio State University)
astro-ph/9509129
Nonlinear Evolution of Genus in Primordial Random-Gaussian Density Field
The genus statistics is studied using large $N$-body simulations for several cosmological models. We consider the effects of nonlinear gravitational evolution, smoothing the particle data in fully nonlinear regime, and the redshift-space distortion on the genus curve. Detailed comparison between the theoretical predict...
1995-09-26
2009-10-28
[ "astro-ph" ]
Takahiko Matsubara and Yasushi Suto (the University of Tokyo)
astro-ph/9509131
Stellar Populations of Bulges and Disks: New Insights from Near-IR Colours
Colours of spiral galaxies generally are affected by the underlying old stellar population, younger stars, and extinction by dust. Old and young populations generally can be disentangled using a combination of blue and near-infrared colours. Extinction effects are very hard to take into account, except for galaxies wit...
1995-09-26
2019-07-31
[ "astro-ph" ]
R.F. Peletier and M. Balcells (Kapteyn Instituut, Groningen, NL)
astro-ph/9509126
Big Bang Nucleosynthesis Constraints on Primordial Magnetic Fields
We reanalyze the effect of magnetic fields in BBN, incorporating several features which were omitted in previous analyses. We find that the effects of coherent magnetic fields on the weak interaction rates and the electron thermodynamic functions (\rhoe, \Pe, and \drhoedt ) are unimportant in comparison to the contribu...
1995-09-25
2014-10-13
[ "astro-ph" ]
Peter. J. Kernan, Glenn D. Starkman and Tammay Vachaspati (CWRU)
astro-ph/9509125
VLBI Observations of the Gravitational Lens System 0957+561
We present hybrid maps of the A and B images of 0957+561 from each of four sessions of 6 cm VLBI observations that span the six-year interval 1987-1993. The inner- and outer-jets are clearly detected, and confirm the structures reported previously. There is no evidence of change in the separation between the core and i...
1995-09-25
2009-10-28
[ "astro-ph" ]
R.M.Campbell, J.Lehar (CfA), B.E.Corey (Haystack), I.I.Shapiro, E.E.Falco (CfA)
astro-ph/9509127
Gravitational Microlensing by Clustered MACHOs
It has been proposed that the MACHOs in our galaxy could be clumped in globular cluster--like associations or RAMBOs (robust associations of massive baryonic objects) (Moore \& Silk 1995). Here we investigate the effect such clustering has on the microlensing of stars in the Large Magellanic Cloud. We find that the len...
1995-09-25
2015-06-24
[ "astro-ph" ]
R Benton Metcalf and Joseph Silk (UC Berkeley)
astro-ph/9509128
Photoionization and the Formation of Dwarf Galaxies
It has been argued that a UV photoionizing background radiation field suppresses the formation of dwarf galaxies, and may even inhibit the formation of larger galaxies. In order to test this, we present gas-dynamical simulations of the formation of small objects in a CDM universe with and without a photoionizing backgr...
1995-09-25
2016-06-08
[ "astro-ph" ]
Thomas Quinn (U. Washington), Neal Katz (U. Washington), and George Efstathiou (Oxford)
astro-ph/9509121
A new spherically symmetric general relativistic hydrodynamical code
In this paper we present a full general relativistic one-dimensional hydro-code which incorporates a modern high-resolution shock-capturing algorithm, with an approximate Riemann solver, for the correct modelling of formation and propagation of strong shocks. The efficiency of this code in treating strong shocks is dem...
1995-09-25
2009-10-28
[ "astro-ph" ]
Jose V. Romero(Univ. Valencia, Dpto Fisica Teorica), Jose M. Ibanez, Jose M. Marti and Juan A. Miralles (Univ. Valencia, Dpto Astronomia y Astrofisica)
astro-ph/9509122
Analytical Models For Galactic Nuclei
I present a general family of dynamical models with simple analytical potential-density pairs suited to model galactic bulges and nuclei with double power-law radial density profiles and an optional central black hole. Analytical expressions for the potential and velocity dispersion of these models are given in the sph...
1995-09-25
2015-06-24
[ "astro-ph" ]
HongSheng Zhao (MPA-Garching)
astro-ph/9509124
Accurate Evaluation of Fermi-Dirac Integrals and Their Derivatives for Arbitrary Degeneracy and Relativity
The equation of state of an ideal Fermi gas is expressed in terms of Fermi-Dirac integrals. We give formulae for evaluation the Fermi-Dirac integrals of orders 1/2, 3/2, and 5/2 and their derivatives in various limits of non- and extreme degeneracy and relativity. We provide tables and a Fortran subroutine for numerica...
1995-09-25
2009-10-28
[ "astro-ph" ]
Juan Antonio Miralles (Valencia) and Kenneth A. Van Riper (LANL)
astro-ph/9509123
Ages of galaxy bulges and disks from optical and near-infrared colours
For a sample of bright nearby early-type galaxies we have obtained surface photometry in bands ranging from U to K. Since the galaxies have inclinations larger than 50 deg. it is easy to separate bulges and disks. By measuring the colours in special regions, we minimize the effects of extinction, and by looking at B-K ...
1995-09-25
2008-02-03
[ "astro-ph" ]
R.F. Peletier and M. Balcells (Kapteyn Instituut, Groningen, NL)
astro-ph/9509117
A New Method for the Determination of the Hubble Parameter
By chance, the slope of the Mv(max) versus (B-V)max relation for recent theoretical models of supernovae of Type Ia (SNe Ia) by Hoflich & Khokhlov is indistinguishable from the slope of a reddening line in the V versus B-V plane. This coincidence allows one to determine a parameter Mv*(max) for SNe Ia that is independe...
1995-09-22
2009-10-28
[ "astro-ph" ]
Sidney van den Bergh
astro-ph/9509115
A Lower Limit on the Age of the Universe
We report the results of a detailed numerical study designed to estimate both the absolute age and the uncertainty in age (with confidence limits) of the oldest globular clusters. Such an estimate is essential if a comparison with the Hubble age of the universe is to be made to determine the consistency, or lack thereo...
1995-09-22
2009-10-28
[ "astro-ph" ]
Brian Chaboyer, Peter J. Kernan, Lawrence M. Krauss, Pierre Demarque
astro-ph/9509119
Some Constraints on Galaxy Evolution Imposed by the Specific Frequency of Globular Clusters
Early-type dwarf galaxies are found to have high specific globular cluster frequencies which are similar to the high S values that are observed in luminous galaxies of types E and S0. It appears unlikely that cluster formation during mergers between dwarf disk systems can account for the high specific globular cluster ...
1995-09-22
2009-10-28
[ "astro-ph" ]
Sidney van den Bergh
astro-ph/9509116
Last Hope for an astrophysical solution to the solar neutrino problem
We discuss what appears the last hope for an astrophysical solution to the solar neutrino problem: a correlated variation of the astrophysical factors for the helium burning cross sections ($S_{33}$ and $S_{34}$) and either $S_{17}$ or the central temperature $T_c$. In this context, we recognize the important role play...
1995-09-22
2011-01-04
[ "astro-ph", "hep-ph" ]
V. Berezinsky, G. Fiorentini and M. Lissia
astro-ph/9509118
Are the Luminosities of RR Lyrae Stars Affected by Second Parameter Effects?
There is a serious discrepancy between the distance to the LMC derived from the Cepheid Period-Luminosity relation and that obtained by using the Galactic calibration for the luminosity of RR Lyrae stars. It is suggested that this problem might be due to the fact that second parameter effects make it inappropriate to a...
1995-09-22
2009-10-28
[ "astro-ph" ]
Sidney van den Bergh
astro-ph/9509114
3D Barred Model of the Milky Way Including Gas
We present a 3D N-body simulation of the Milky Way including 4*10^5 star- and dark-like particles and 2*10^4 gas particles, initially distributed according to an axisymmetric, observationally constrained, mass model. The whole system is self-gravitating and the gas hydrodynamics is solved using the SPH method. The simu...
1995-09-22
2008-02-03
[ "astro-ph" ]
R. Fux and D. Friedli
astro-ph/9509113
Three-integral oblate galaxy models
A simple numerical scheme is presented for the construction of three-integral phase-space distribution functions for oblate galaxy models with a gravitational potential of St\"{a}ckel form, and an arbitrary axisymmetric luminous density distribution. The intrinsic velocity moments can be obtained simultaneously with li...
1995-09-22
2015-06-24
[ "astro-ph" ]
F.H.A. Robijn and P.T. de Zeeuw
astro-ph/9509107
Cosmological Simulations with TreeSPH
We describe numerical methods for incorporating gas dynamics into cosmological simulations and present illustrative applications to the cold dark matter (CDM) scenario. Our evolution code, a version of TreeSPH (Hernquist \& Katz 1989) generalized to handle comoving coordinates and periodic boundary conditions, combines...
1995-09-21
2011-08-31
[ "astro-ph" ]
Neal Katz (U. Washington), David H. Weinberg (Ohio State), and Lars Hernquist (U.C. Santa Cruz)
astro-ph/9509110
The optical spectrum of HR 4049 (includes a line identification from 3650 to 10850ang)
High-resolution optical spectra (UES/WHT) of the extreme metal-poor post-AGB star HR4049 were obtained at four different orbital phases. The spectra cover the wavelength region from 3650ang to 10850ang at a resolution of R=5.2x10^4. These observations are supplemented with four high-resolution spectra of the NaI D1 & D...
1995-09-21
2019-08-15
[ "astro-ph" ]
Eric J. Bakker, Frank L.A. Van der Wolf, Henny J.G.L.M. Lamers, Austin F. Gulliver, Roger Ferlet, Alfred Vidal-Madjar
astro-ph/9509112
Nonlinear Damping of Oscillations in Tidal-Capture Binaries
We calculate the damping of quadrupole f and low order g modes (primary modes) by nonlinear coupling to other modes of the star. This damping is orders of magnitude more rapid than direct radiative damping when the primary amplitude is large, as in tidal capture. Primary modes destabilize high degree g-modes of half ...
1995-09-21
2016-08-30
[ "astro-ph" ]
Pawan Kumar (IAS and MIT) and Jeremy Goodman (Princeton)
astro-ph/9509106
Damped Lyman-alpha and Lyman Limit Absorbers in the Cold Dark Matter Model
We study the formation of damped \lya and Lyman limit absorbers in a hierarchical clustering scenario using a gas dynamical simulation of an $\Omega = 1$, cold dark matter universe. In the simulation, these high column density systems are associated with forming galaxies. Damped \lya absorption, $N_{HI} \simgt 10^{20.2...
1995-09-21
2009-10-28
[ "astro-ph" ]
Neal Katz (U. Washington), David H. Weinberg (Ohio State), Lars Hernquist (U.C. Santa Cruz), and Jordi Miralda-Escude (IAS)
astro-ph/9509105
The Lyman-alpha Forest in the Cold Dark Matter Model
Cosmological simulations with gas provide a detailed description of the intergalactic medium, making possible predictions of neutral hydrogen absorption in the spectra of background QSOs. We present results from a high-resolution calculation of an $\Omega=1$ cold dark matter model. Our simulation reproduces many of the...
1995-09-21
2009-10-28
[ "astro-ph" ]
Lars Hernquist (U.C. Santa Cruz), Neal Katz (U. Washington), David H. Weinberg (Ohio State), and Jordi Miralda-Escude (IAS)
astro-ph/9509108
Dust in High Redshift Radio Galaxies and the Early Evolution of Spheroidal Galaxies
Several lines of evidence suggest that early-type galaxies might have been very dusty during their initial evolutionary stages, characterized by intense star formation activity. The radio selection has provided, by far, the richest samples of high-$z$ galaxies, most likely of early type, which may therefore yield cruci...
1995-09-21
2015-06-24
[ "astro-ph" ]
Paola Mazzei and Gianfranco De Zotti
astro-ph/9509109
Field Stars and Clusters of the Galactic Bulge: Implications for Galaxy Formation
The results of a kinematic study of the Galactic bulge based on spectra of red giants in fields at projected distances of 1.4-1.8 kpc from the Galactic center are presented. There is a marked trend of kinematics with metallicity, in the sense that the more metal-poor population has higher velocity dispersion and lower ...
1995-09-21
2009-10-28
[ "astro-ph" ]
Dante Minniti
astro-ph/9509111
A study on the nature of the peculiar supergiant HD101584
We present a study of low- and high-resolution ultraviolet, high-resolution optical CAT/CES spectra and ultraviolet, optical and infrared photometry of the peculiar supergiant HD101584. From the photometry we learn that the ultraviolet and optical energy distribution cannot be fitted in a consistent way and we need a m...
1995-09-21
2016-08-30
[ "astro-ph" ]
Eric J. Bakker, Henny J.G.L.M. Lamers, L.B.F.M. Waters, Christoffel Waelkens, Norman R. Trams, Hans van Winckel
astro-ph/9509120
Optical Identification of Quasar 0917+7122 in the Direction of an Extreme-Ultraviolet Source
We report the optical identification of an $R=18.3$ mag, $z=2.432$ quasar at the position of a 6 cm radio source and a faint \rosat PSPC X-ray source. The quasar lies within the error circles of unidentified extreme-UV (EUV) detections by the \euve and \rosat WFC all-sky surveys at $\sim 400$ \AA\ and $\sim 150$ \AA, r...
1995-09-21
2007-05-23
[ "astro-ph" ]
Dan Maoz, Eran Ofek, Amotz Shemi, Aaron Barth, Alexei Filippenko, Michael Brotherton, Beverley Wills, Derek Wills, and Felix J. Lockman
astro-ph/9509102
Wavelet Analysis of One-Dimensional Cosmological Density Fluctuations
Wavelet analysis is proposed as a new tool for studying the large-scale structure formation of the universe. To reveal its usefulness, the wavelet decomposition of one-dimensional cosmological density fluctuations is performed. In contrast with the Fourier analysis, the wavelet analysis has advantage of its ability to ...
1995-09-20
2009-10-28
[ "astro-ph" ]
Yoshi Fujiwara and Jiro Soda (Kyoto University)
astro-ph/9509103
CCD Photometry of Dwarf Nova AL Com in Superoutburst
We report a CCD optical photometry of a dwarf nova AL Com in superoutburst. Before superhumps occurred the light curve was highly variable with dominant periods about 41 minutes and 81.5 minutes for different nights. The period of observed superhumps is 82.5 minutes and seems to be stable. The first harmonic of the bas...
1995-09-20
2007-05-23
[ "astro-ph" ]
W. Pych and A. Olech (Warsaw University Observatory)
astro-ph/9509104
Spectrophotometry of globular clusters in NGC5128
We have carried out spectrophotometry in the range 3600--9700\AA~ of five globular clusters in NGC 5128 for which previous photometric studies suggested a high metal content. We compare the equivalent widths of a set of metallic features of the NGC 5128 clusters with those of well-studied Galactic and M31 globular clus...
1995-09-20
2007-05-23
[ "astro-ph" ]
Jablonka, Bica, Pelat, Alloin
astro-ph/9509095
The host galaxies of z=2 radio-quiet QSOs
Based on an $R$-band imaging survey of high-redshift ($z \approx 2$) QSOs with the 4.2m WHT, we report the detection of extensions to the nuclear PSFs of two radio-quiet and one radio-loud QSO. The extensions are most likely host galaxies, with luminosities of at least $3-7$\% of the QSO luminosity. The most likely val...
1995-09-19
2007-05-23
[ "astro-ph" ]
I. Aretxaga, B.J. Boyle, R.J. Terlevich
astro-ph/9509094
The observability of old neutron stars accreting the interstellar medium: III. The solar proximity
Old isolated accreting neutron stars may show up among unidentified soft X--ray sources detected by the ROSAT All Sky Survey. We argue that the chances of identification are greater for ONSs located in the closest overdense regions of the solar neighbourhood. In particular, we consider the neutral hydrogen wall in the ...
1995-09-19
2007-05-23
[ "astro-ph" ]
Silvia Zane, Luca Zampieri, Roberto Turolla and Aldo Treves
astro-ph/9509093
Radiative Transfer in a Clumpy Universe: II. The Utraviolet Extragalactic Background
We present a detailed calculation of the propagation of AGN-like ionizing radiation through the intergalactic space. We model the ionization state of absorbing clouds, and show that the universe will be more opaque above $4\,$Ryd than previously estimated. Singly ionized helium in \Lya forest clouds and Lyman-limit sys...
1995-09-19
2009-10-28
[ "astro-ph" ]
Francesco Haardt and Piero Madau
astro-ph/9509097
The extended narrow line region in Mkn79. I.Observations
We present deep long slit spectra of Mkn79 in position angles PA=12$^{o}$ and PA=50$^{o}$ obtained with the WHT. These data prove the existence of an extended narrow line region in PA=12$^{o}$, which coincides with the triplet radio structure (Ulvestad \& Wilson 1984) and the observed outflow of material from the nucle...
1995-09-19
2007-05-23
[ "astro-ph" ]
L.S.Nazarova, P.T.O'Brien and M.J.Ward
astro-ph/9509092
Gamow-Teller strength distributions for nuclei in pre-supernova stellar cores
Electron-capture and $\beta$-decay of nuclei in the core of massive stars play an important role in the stages leading to a type II supernova explosion. Nuclei in the f-p shell are particularly important for these reactions in the post Silicon-burning stage of a presupernova star. In this paper, we characterise the ene...
1995-09-19
2008-11-26
[ "astro-ph", "nucl-th" ]
F. K. Sutaria and A. Ray (Astrophys. Group, Tata Institute, Bombay)
astro-ph/9509096
The accretion luminsoity of a massive black hole in an elliptical galaxy
Most large elliptical galaxies should now host a massive black hole leftover from an earlier quasar phase. Such galaxies also have an extensive hot gaseous halo. Here we consider why the nuclei of elliptical galaxies are not luminous sources due to the accretion of the hot gas by the central black hole, yet have weak r...
1995-09-19
2016-06-08
[ "astro-ph" ]
A.C. Fabian, M.J. Rees
astro-ph/9509101
Spectroscopy of the white-dwarf companions of PSR~0655+64 and 0820+02
We present spectra of the white-dwarf companions of the radio pulsars 0655+64 and 0820+02. For the latter, we find a spectrum showing strong lines of hydrogen, i.e., that of a DA star. From modelling these lines, the mass of a white dwarf can, in principle, be determined accurately, thus leading to constraints on the e...
1995-09-19
2009-10-28
[ "astro-ph" ]
M. H. van Kerkwijk and S. R. Kulkarni (Palomar Observatory, Caltech)
astro-ph/9509099
Detection of Extended Polarized Ultraviolet Radiation from the z = 1.82 Radio Galaxy 3C 256
We have detected spatially extended linear polarized UV emission from the high-redshift radio galaxy 3C~256 ($z=1.82$). A spatially integrated ($7.8''$ diameter aperture) measurement of the degree of polarization of the $V-$band (rest frame 0.19 $\mu$m) emission yields a value of 16.4\% ($\pm 2.2$\%) with a position an...
1995-09-19
2009-10-28
[ "astro-ph" ]
Buell T. Jannuzi, Richard Elston, Gary D. Schmidt, Paul S. Smith, and H. S. Stockman
astro-ph/9509091
Energy Spectra and Elemental Composition of Nuclei above 100 TeV from a Series of JACEE Balloon Flights
The Japanese-American Cooperative Emulsion Experiment (JACEE) has recently carried out a series of Antarctic circumpolar balloon flights (JACEE-10 ~ JACEE-13) for the study of high energy elemental composition and energy spectra of cosmic rays. The total exposure factor of these experiments is 663 m**2-hr, which is abo...
1995-09-19
2007-05-23
[ "astro-ph" ]
The JACEE Collaboration: K. Asakimori, et al
astro-ph/9509098
The Nature and Evolution of Absorption-Selected Galaxies
We present results of surveys for high redshift galaxies selected by their having produced detectable Mg~II and Lyman limit absorption in the spectra of background QSOs. We discuss the properties of the absorbing galaxies, the connection between galaxy properties and absorption line signatures, and how a combination of...
1995-09-19
2007-05-23
[ "astro-ph" ]
C. Steidel (Caltech)
astro-ph/9509100
The Discovery of Halley-sized Kuiper Belt Objects Using HST
We report the statistical detection (at the >99% confidence level) of a population of 28th magnitude objects exhibiting proper motions of ~1 arcsecond per hour at quadrature in deep HST/WFPC2 images. The drift directions imply a preponderance of objects on prograde orbits concentrated near the ecliptic plane. We interp...
1995-09-19
2009-10-28
[ "astro-ph" ]
Anita L. Cochran (U. Texas), Harold F. Levison, S. Alan Stern (SwRI), Martin J. Duncan (Queen's U.)
astro-ph/9509087
Do OB Runaway Stars Have Pulsar Companions?
We have conducted a VLA search for radio pulsars at the positions of 44 nearby OB runaway stars. The observations involved both searching images for point sources of continuum emission and a time series analysis. Our mean flux sensitivity to pulsars slower than 50 ms was 0.2 mJy. No new pulsars were found in the survey...
1995-09-18
2009-10-28
[ "astro-ph" ]
Colin J. Philp (UNC-CH), Charles R. Evans (UNC-CH), Peter J.T. Leonard (UMD) and Dale A. Frail (NRAO-VLA)
astro-ph/9509090
Time-Variation of Newton's Constant and the Age of Globular Clusters
A variation of Newton's constant $G$ over cosmological time scales would modify the main-squence time of globular cluster (GC) stars. We have calculated the evolution of low-mass stars typical for GCs both for standard non-varying $G$ and under the assumption of a linear variation of $G$. The age of the isochrones resu...
1995-09-18
2011-05-23
[ "astro-ph", "gr-qc", "hep-ph" ]
S. Degl'Innocenti, G. Fiorentini, G.G. Raffelt, B. Ricci, and A. Weiss
astro-ph/9509089
Lyman Limit Imaging of High Redshift Galaxies. III. New Observations of 4 QSO Fields
We present the results of deep Lyman limit imaging in four new fields as part of a continuing search for galaxies at $3.0 \le z \le 3.5$. The technique uses a custom broad--band filter set ($U_n G {\cal R}$) designed to isolate objects having Lyman continuum breaks superposed on otherwise flat--spectrum ultraviolet con...
1995-09-18
2009-10-28
[ "astro-ph" ]
C. Steidel, M. Pettini, D. Hamilton
astro-ph/9509086
Genus Statistics of the Large-Scale Structure with Non-Gaussian Density Fields
As a statistical measure to quantify the topological structure of the large-scale structure in the universe, the genus number is calculated for a number of non-Gaussian distributions in which the density field is characterized by a nontrivial function of some Gaussian-distributed random numbers. As a specific example, ...
1995-09-18
2009-10-28
[ "astro-ph" ]
Takahiko Matsubara and Jun'ichi Yokoyama
astro-ph/9509088
Far-Infrared Water Line Emissions From Circumstellar Outflows
We have modeled the far-infrared water line emission expected from circumstellar outflows from oxygen-rich late-type stars, as a function of the mass-loss rate and the terminal outflow velocity. For each mass-loss rate and terminal outflow velocity considered, we computed self-consistently the gas density, temperature,...
1995-09-18
2009-10-28
[ "astro-ph" ]
Wesley Chen and David A. Neufeld (Johns Hopkins University)
astro-ph/9509085
Accretion Discs with Accreting Coronae in AGN - II. Nuclear Wind
We study an accretion disc with a hot continuous corona. We assume that the corona itself accretes and therefore it is powered directly by the release of the gravitational energy and cooled by radiative interaction with the disc. We consider the vertical structure of such a corona and show that the radial infall is acc...
1995-09-17
2015-06-24
[ "astro-ph" ]
H.J. Witt, B. Czerny and P.T. Zycki
astro-ph/9509083
Atomic data for astrophysics. I. Radiative recombination rates for H-like, He-like, Li-like and Na-like ions over a broad range of temperature
We present new calculations and analytic fits to the rates of radiative recombination towards H-like, He-like, Li-like and Na-like ions of all elements from H through Zn (Z=30). The fits are valid over a wide range of temperature, from 3 K to 10**9 K.
1995-09-16
2009-10-28
[ "astro-ph", "atom-ph" ]
D.A. Verner and G.J. Ferland (University of Kentucky)
astro-ph/9509080
Dynamical Search for Substructures in Galaxy Clusters, A Hierarchical Clustering Method
We propose a new hierarchical method which uses dynamical arguments to find and describe substructures in galaxy clusters. This method (hereafter h--method or h--analysis) uses a hierarchical clustering analysis to determine the relationship between galaxies according to their relative binding energies. We have tested ...
1995-09-15
2007-05-23
[ "astro-ph" ]
Arturo Serna (Obs Paris Meudon), Daniel Gerbal (IAP)
astro-ph/9509078
BATSE Observations of the Large-Scale Isotropy of Gamma-Ray Bursts
We use dipole and quadrupole statistics to test the large-scale isotropy of the first 1005 gamma-ray bursts observed by the Burst and Transient Source Experiment (BATSE). In addition to the entire sample of 1005 gamma-ray bursts, many subsets are examined. We use a variety of dipole and quadrupole statistics to search ...
1995-09-15
2009-10-28
[ "astro-ph" ]
Michael S. Briggs, William S. Paciesas, and Geoffrey N. Pendleton (UAH), Charles A. Meegan, Gerald J. Fishman, John M. Horack, and Martin Brock (MSFC), Chryssa Kouveliotou (USRA), Dieter H. Hartmann (Clemson), and Jon Hakkila (Mankato State)
astro-ph/9509081
Environmental effects on the structure of the Dwarf Spheroidal Galaxies
The central surface brightness ($\mu_V(0)$) of the dwarf spheroidal satellites of our own Galaxy is found to correlate with their distance from the Galactic Center ($R_{GC}$). This observational evidence suggests that environmental effects could strongly influence their structure. This suggestion is further supported b...
1995-09-15
2015-06-24
[ "astro-ph" ]
M. Bellazzini, F. Fusi Pecci and F.R. Ferraro
astro-ph/9509082
Current Cosmological Simulations, Advice on their Interpretation, and an IMAX Film Preview
This general talk is geared toward non-specialists and addresses three questions: (1) What types of cosmological simulations are done? (2) What are the relevant problems to address and what results can one expect? (3) How can one tell if the results are reasonable?
1995-09-15
2007-05-23
[ "astro-ph" ]
F J Summers (Princeton University)
astro-ph/9509079
Combined stellar structure and atmosphere models for massive stars: Wolf-Rayet models with spherically outflowing envelopes
We present a simple analytical method to describe the structure of a spherically expanding envelope with strong mass outflow. The structure is consistently connected to the hydrostatic stellar interior and provides an adequate description of the outer boundary conditions for stellar models with large mass loss rates. W...
1995-09-15
2008-02-03
[ "astro-ph" ]
D. Schaerer (Geneva Observatory)
astro-ph/9509084
Mode Identification of the Slowly Pulsating F0V Star V398 Aurigae (9 Aur)
We have investigated the F0V star V398\,Aurigae (= 9 Aur) under the assumption that it is undergoing non-radial gravity mode oscillations and that the two principal periods given by Krisciunas et al. (1995) are correct. We find that the two periods are manifestations of an $\ell=3, |m|=1$ spheroidal mode and its toroid...
1995-09-15
2015-06-24
[ "astro-ph" ]
Conny Aerts, Kevin Krisciunas
astro-ph/9509073
Luminous Quasars in Luminous Early-Type Host Galaxies
Some recent observations of nearby quasars with HST have apparently failed to detect host galaxies. We review the HST observations as well as near infrared ground-based observations of the same objects. We find that the quasar hosts can be detected in the HST data if they are smoothed sufficiently to reveal low surface...
1995-09-14
2009-10-28
[ "astro-ph" ]
K. K. McLeod (SAO) and G. H. Rieke (Steward)
astro-ph/9509074
On the Density of PBH's in the Galactic Halo
Calculations of the rate of local Primordial Black Hole explosions often assume that the PBH's can be highly concentrated into galaxies, thereby weakening the Page-Hawking limit on the cosmological density of PBH's. But if the PBH's are concentrated by a factor exceeding $c/(H_\circ R_\circ) \approx 4 \times 10^5$, whe...
1995-09-14
2009-10-28
[ "astro-ph" ]
Edward L. Wright (UCLA Physics & Astronomy Dept.)
astro-ph/9509076
Molecular gas observations and enhanced massive star formation efficiencies in M100
We present new J=1-0 12-CO observations along the northern spiral arm of the grand-design spiral galaxy M100 (NGC 4321), and study the distribution of molecular hydrogen as derived from these observations, comparing the new data with a set of data points on the southern arm published previously. We compare these measur...
1995-09-14
2007-05-23
[ "astro-ph" ]
J.H. Knapen (Univ. de Montreal), J.E. Beckman, J. Cepa (IAC Tenerife), N. Nakai (Nobeyama R.O.)
astro-ph/9509077
The Mass Distribution in Clusters of Galaxies from Weak and Strong Lensing
This paper is intended as an introduction to the theory of weak lensing. A review of the inversion formula introduced by Kaiser and Squires is presented. We then prove the formula of the aperture densitometry method in a simple way that allows a clear understanding of where the various terms come from. This is particul...
1995-09-14
2007-05-23
[ "astro-ph" ]
Jordi Miralda-Escude
astro-ph/9509072
High angular resolution coronography for adaptive optics
Recent adaptive optics systems in astronomy achieve high-angular resolution. With the extreme stability of the images, detection at very low fluxes can be reached using a coronograph at the diffraction limit of the telescopes. This paper is an overview of the issues of stellar coronography used at the diffraction limit...
1995-09-14
2007-05-23
[ "astro-ph" ]
Fabien Malbet (Laboratoire d'Astrophysique, Observatoire de Grenoble)
astro-ph/9509075
Another Look at Gaussian Isocurvature Hot Dark Matter Models For Large- Scale Structure
We examine Gaussian isocurvature hot dark matter (massive neutrino) models for large-scale structure in which the initial density perturbations are produced in the baryons with a power--law spectrum $P_B(k) = Ak^{n_B}$. We calculate the linearly-evolved power spectrum and cosmic microwave fluctuations. We find that mod...
1995-09-14
2009-10-28
[ "astro-ph" ]
Andrew A. de Laix (Case Western Reserve University) and Rober J. Scherrer (The Ohio State University)
astro-ph/9509070
Accretion discs around black holes: two dimensional, advection cooled flows
Two-dimensional accretion flows near black holes have been investigated by time-dependent hydrodynamical calculations. We assume that the flow is axisymmetric and that radiative losses of internal energy are negligible, so that the disc is geometrically thick and hot. Accretion occurs due to the overflow of the effecti...
1995-09-13
2015-06-24
[ "astro-ph" ]
Igor V. Igumenshchev, Xingming Chen and Marek A. Abramowicz
astro-ph/9509071
Accurate Wavenumbers for Mid-Infrared Fine-Structure Lines
We present accurate new wavenumbers for a set of 13 mid-infrared fine-structure lines. The wavenumbers were determined from observations of the planetary nebula NGC 7027 and of the red supergiant Alpha Scorpii. Most of the new wavenumbers are good to within 0.0025%, or 8 km/s. We provide details on the measurements and...
1995-09-13
2009-10-28
[ "astro-ph" ]
Douglas M. Kelly and John H. Lacy (Dept. of Ast., U. of Texas)
astro-ph/9509069
Incorporating Morphological Types into Semi-analytic Schemes for Galaxy Formation
We test the hypothesis that elliptical galaxies are formed by violent mergers in a universe with hierarchical structure formation. Within the framework of a semi-analytic scheme for galaxy formation, we predict the distribution of morphological types with redshift and compare the colours of elliptical galaxies in diffe...
1995-09-13
2007-05-23
[ "astro-ph" ]
C.M.Baugh (Durham University)
astro-ph/9509068
Continuum emission associated with 6.7-GHz methanol masers
We have used the Australia Telescope Compact Array (ATCA) to search for continuum emission toward three strong 6.7-GHz methanol maser sources. For two of the sources, G339.88-1.26 and NGC 6334F (G351.42+0.64), we detect continuum emission closely associated with the methanol masers. A further three clusters of masers s...
1995-09-13
2015-06-24
[ "astro-ph" ]
S.P. Ellingsen (Uni of Tas), R.P. Norris (ATNF), P.M. McCulloch (Uni of Tas)
astro-ph/9509067
A Study of Absorption Features in the Three Micron Spectra of Molecular Cloud Sources with H$_2$O Ice Bands
New 3.3--3.6~$\mu$m spectra were obtained of nine young stellar objects embedded in molecular clouds. An absorption feature at $\sim$3.47~$\mu$m (2880~cm$^{-1}$) with FWHM$\sim$0.09 $\mu$m (80 cm$^{-1}$), first identified by Allamandola et al. (1992), was definitively detected toward seven objects, and marginally in th...
1995-09-12
2009-10-28
[ "astro-ph" ]
T. Y. Brooke (Jet Propulsion Laboratory), K. Sellgren (Ohio State University), and R. G. Smith (University of New South Wales)
astro-ph/9509062
The Helium-Core Mass at the Helium Flash in Low-Mass Red Giant Stars: Observations and Theory
The method developed by Raffelt (1990a,b,c) to estimate a possible increase in the standard values of the helium-core mass at the tip of the red giant branch, $\Mc$, from properties of the color-magnitude diagrams of Galactic globular clusters is employed. In the present study, we revise and update Raffelt's database, ...
1995-09-12
2009-10-28
[ "astro-ph", "hep-ph" ]
M. Catelan, J.A. de Freitas Pacheco, and J.E. Horvath
astro-ph/9509066
Simulating Our Cosmological Neighborhood: Mock Catalogs for Velocity Analysis
We describe the construction of an N-body simulation that mimics the true velocity and mass-density fields in a box of side 256\hmpc about the Local Group , and the production of mock catalogs that mimic in detail current catalogs of redshifts and peculiar velocities. Our main purpose is to provide a tool for developin...
1995-09-12
2009-10-28
[ "astro-ph" ]
Tsafrir Kolatt, Avishai Dekel, Galit Ganon, and Jeffrey Willick
astro-ph/9509065
The Case Against Bimodal Star Formation in Elliptical Galaxies
We consider the present-day photometric and chemical properties of elliptical galaxies, adopting the bimodal star formation scenario of Elbaz, Arnaud & Vangioni-Flam (1995). These models utilise an initial mass function (IMF) biased heavily toward massive stars during the early phases of galactic evolution, leading to ...
1995-09-12
2015-06-24
[ "astro-ph" ]
Brad K. Gibson (University of Oxford)
astro-ph/9509063
Globular Cluster Ages and the Formation of the Galactic Halo
Main sequence turnoff magnitudes from the recent set of Yale isochrones (Chaboyer \ea 1995) have been combined with a variety of relations for the absolute magnitude of RR Lyr stars (\mvrr) to calibrate age as a function of the difference in magnitude between the main sequence turn-off and the horizontal branch (\dv). ...
1995-09-12
2009-10-28
[ "astro-ph" ]
Brian Chaboyer (CITA), P. Demarque (Yale) & Ata Sarajedini (KPNO)
astro-ph/9509064
Problems of Dark Matter
The data indicating existence of different forms of dark matter in the universe as well as the role of this matter in structure formation are briefly reviewed. It is argued that vacuum energy gives a dominant contribution into the total energy density of the universe. The model of structure formation with unstable tau-...
1995-09-12
2007-05-23
[ "astro-ph" ]
A.D. Dolgov
astro-ph/9509058
Anomalous Transport and Particle Acceleration at Shocks
The theory of first order Fermi acceleration at shocks assumes that particles diffuse due to scattering off slow-moving magnetic irregularities. However, cosmic rays are closely tied to magnetic field lines, and the transport process, particularly across the direction of the field, is likely to be more complicated. To ...
1995-09-11
2011-05-23
[ "astro-ph" ]
P. Duffy, J.G. Kirk, Y.A. Gallant, R.O. Dendy
astro-ph/9509061
Faint Extended X-ray Sources: A new Large Area Survey
We have searched for extended X-ray sources in the ROSAT PSPC archive using the Voronoi Tesslation and Percolation algorithm (VTP). This algorithm detects all significant sources regardless of shape or size, and is particularly suited to finding low surface brightness extended sources which could be missed or wrongly i...
1995-09-11
2007-05-23
[ "astro-ph" ]
L.R.Jones, C.A.Scharf (NASA/Goddard), H.Ebeling (IoA, Camb), E.Perlman (NASA/Goddard), M.Malkan (UCLA), G.Wegner (Dartmouth)
astro-ph/9509060
Statistics and properties of HII regions in a sample of grand design galaxies I. Luminosity functions
We present new high quality continuum-subtracted H alpha images of the grand-design galaxies NGC 157, NGC 3631, NGC 6764 and NGC 6951. We have determined the positions, angular sizes, and fluxes of their individual HII regions, and describe statistical properties of the HII region samples. We construct luminosity funct...
1995-09-11
2007-05-23
[ "astro-ph" ]
M. Rozas, J.E. Beckman (IAC Tenerife), J.H. Knapen (Univ. de Montreal)
astro-ph/9509059
Inelastic clump collision model for non-Gaussian velocity distribution in molecular clouds
Non-Gaussian velocity distribution in star forming region is reproduced by inelastic clump collision model. We numerically calculated the evolution of inelastic hard spheres in sheared flow, which corresponds to cloud clumps in differential galactic rotation. This system fluctuates largely around equilibrium state, cre...
1995-09-11
2008-02-03
[ "astro-ph" ]
Shigeru Ida (Department of Earth and Planetary Science, Tokyo Institute of Technology, Tokyo, Japan) and Y-h. Taguchi (Department of Physics, Tokyo Institute of Technology, Japan, http://www.phys.titech.ac.jp/~tag/)
astro-ph/9509057
Invisible Matter
These lectures have been given to particle physicists, mostly experimentalists and very briefly and at a pedestrian level review the problems of dark matter. The content of the lectures is the following: 1. Introduction. 2. Cosmological background. 3. Luminous matter. 4. Primordial nucleosynthesis and the total...
1995-09-10
2015-06-24
[ "astro-ph", "hep-ph" ]
A.D. Dolgov
astro-ph/9509055
Recent progress in the search for black holes in galactic nuclei
Massive nuclear black holes of 10^6 - 10^9 solar masses are believed to be responsible for the the energy production in quasars and active galaxies, and are thought to be present in many quiescent galaxies as well. Dynamical evidence for this can be sought by studying the dynamics of gas and stars in galactic nuclei at...
1995-09-09
2007-05-23
[ "astro-ph" ]
Roeland P. van der Marel
astro-ph/9509053
The New Universe Fixed by a Standing Wave Particle Model
The theoretical properties of the black holes (BHs) and of the universe were derived from a unified relativistic theory based on a generalization of local relativity for nonlocal cases in gravitational fields and a quantized standing wave particle model that accounts for relativity, quantum mechanics and the gravitatio...
1995-09-09
2008-02-03
[ "astro-ph", "gr-qc" ]
Rafael A. Vera
astro-ph/9509056
A Serendipitous Deep Cluster Survey from ROSAT--PSPC pointed observations
We present a deep X-ray selected sample of galaxy clusters which has been created from a serendipitous search in ROSAT-PSPC deep pointed observations at high galactic latitude. This survey, hereafter known as the ROSAT Deep Cluster Survey (RDCS), is being carried out utilizing a wavelet-based detection algorithm which,...
1995-09-09
2007-05-23
[ "astro-ph" ]
P.Rosati
astro-ph/9509050
Halo Star Evolution
In this review, I will discuss a few problems which point to the need for improved stellar evolution models of halo stars. Current stellar evolution models do not match the observed $^7$Li abundance patterns, suggesting that the input physics and/or the assumptions used in constructing the models are in need of revisio...
1995-09-08
2007-05-23
[ "astro-ph" ]
Brian Chaboyer (CITA)
astro-ph/9509051
Low-mass star formation in CG1: a diffraction limited search for pre-main sequence stars next to NX Pup
Using adaptive optics at the ESO 3.6m telescope, we obtained diffraction limited JHK-images of the region around the Herbig AeBe star NX Pup. We clearly resolved the close companion (sep. 0.128") to NX Pup -- originally discovered by HST -- and measured its JHK magnitudes. A third object at a separation of 7.0" from NX...
1995-09-08
2007-05-23
[ "astro-ph" ]
W. Brandner, J. Bouvier, E.K. Grebel, E. Tessier, D. de Winter, and J.-L. Beuzit
astro-ph/9509052
Universality of the Network and Bubble Topology in Cosmological Gravitational Simulations
Using percolation statistics we, for the first time, demonstrate the universal character of a network pattern in the real space, mass distributions resulting from nonlinear gravitational instability of initial Gaussian fluctuations. Percolation analysis of five stages of the nonlinear evolution of five power law models...
1995-09-08
2009-10-28
[ "astro-ph" ]
Capp Yess and Sergei F. Shandarin (University of Kansas, Lawrence, KS)