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astro-ph/9410030
The ESO All-Southern-Sky Redshift Survey of ROSAT Clusters of Galaxies
We discuss the rationale and the present status of a large redshift survey aiming at measuring distances for all the clusters of galaxies detected by the ROSAT X--ray All--Sky Survey in the southern hemisphere, with flux larger than $\sim 2\times 10^{-12}$ erg s$^{-1}$ cm$^{-2}$. The survey is being performed using thr...
1994-10-11
2007-05-23
[ "astro-ph" ]
Luigi Guzzo, et al
astro-ph/9410028
On strangelets in magnetosphere
A short discussion is provided on the hypothesis of strange quark dust of low specific charge in the terrestrial magnetosphere. We suggest by means of rough estimates the possible existence of a strangelet belt in the magnetosphere.
1994-10-10
2008-11-26
[ "astro-ph" ]
Haret C. Rosu
astro-ph/9410029
Pictor A: A New Double-Peaked Emission Line Quasar
We obtained a new spectrum for the radio galaxy Pictor~A in December 1993. Comparison with previous data obtained in 1983 and 1987 shows that the broad component of the Balmer lines has increased considerably in strength and complexity. The Balmer lines now show a boxy, double peaked profile with FWZI$\sim$24000 \kms. ...
1994-10-10
2009-10-22
[ "astro-ph" ]
J. W. Sulentic, P. Marziani, T. Zwitter, M. Calvani
astro-ph/9410027
Nucleosynthesis in the Presence of Primordial Isocurvature Baryon Fluctuations
We study big bang nucleosynthesis in the presence of large mass-scale, non-linear entropy fluctuations. Overdense regions, with masses above the local baryon-Jeans mass, are expected to collapse and form condensed objects. Surviving nucleosynthesis products therefore tend to originate from underdense regions. We comput...
1994-10-07
2009-10-22
[ "astro-ph" ]
K. Jedamzik and G.M. Fuller
astro-ph/9410026
Modelling Galaxies with f(E,Lz); a Black Hole in M32
A technique for the construction of axisymmetric distribution functions for individual galaxies is presented. It starts from the observed surface bright- ness distribution, which is deprojected to gain the axisymmetric luminosity density, from which follows the stars' gravitational potential. After adding dark mass com...
1994-10-07
2015-06-24
[ "astro-ph" ]
Walter Dehnen
astro-ph/9410021
Accretion Disc Turbulence and the X-Ray Power Spectra of Black Hole High States
The high state of black hole candidates is characterized by a quasi- thermal emission component at $kT \sim 1$ keV. In addition, this state tends to have very low variability which indicates that it is relatively stable, at least on {\it short} time scales. Most models of the high state imply that the bulk of the emiss...
1994-10-06
2015-06-24
[ "astro-ph" ]
Michael A. Nowak and Robert V. Wagoner
astro-ph/9410022
Damped Lyman Alpha Systems vs. Cold + Hot Dark Matter
Damped Ly$\alpha$ systems provide possibly the most significant evidence for early structure formation, and thus a stringent constraint on the Cold + Hot Dark Matter (CHDM) cosmology. Using the numbers of halos in N-body simulations to normalize Press-Schechter (PS) estimates of the number densities of protogalaxies as...
1994-10-06
2009-09-25
[ "astro-ph" ]
Anatoly Klypin, Stefano Borgani, Jon Holtzman, & Joel Primack
astro-ph/9410024
CBR Temperature Fluctuations Induced by Gravitational Waves in a Spatially-Closed Inflationary Universe
Primordial gravitational waves are created during the de Sitter phase of an exponentially-expanding (inflationary) universe, due to quantum zero-point vacuum fluctuations. These waves produce fluctuations in the temperature of the Cosmic Background Radiation (CBR). We calculate the multipole moments of the correlation ...
1994-10-06
2022-09-07
[ "astro-ph", "gr-qc", "hep-th" ]
Bruce Allen, Robert Caldwell, Scott Koranda
astro-ph/9410025
Field Galaxy Evolution Since Z~1 from a Sample of QSO Absorption-Selected Galaxies
We present some of the results of a large survey aimed at establishing the properties of galaxies selected by their having produced detectable Mg~II $\lambda\lambda 2796$, 2803 absorption in the spectra of background QSOs. The present sample covers the redshift range $0.2 \le z \le 1.0 $, with $\langle z \rangle = 0.65...
1994-10-06
2019-08-15
[ "astro-ph" ]
C. Steidel, M. Dickinson, and S.E. Persson
astro-ph/9410023
Dispersal and Mixing of Oxygen in the Interstellar Medium of Gas-Rich Galaxies
Stellar and nebular abundance indicators reveal that there exists significant abundance fluctuations in the interstellar medium (ISM) of gas-rich galaxies. It is shown that at the present observed solar level of O/H $\sim 6 \times 10^{-4}$, abundance differences of a factor of two, such as existing between the Sun and ...
1994-10-06
2007-05-23
[ "astro-ph" ]
Jean-Rene ROY (Quebec,Canada), Daniel KUNTH (Paris,France)
astro-ph/9410020
A New Method for Measuring the Hi Gunn-Peterson Effect at High Redshift
In order to carry out a systematic and thorough measurement of the HI Gunn-Peterson effect at high redshift, a quantitatively testable and repeatable procedure, in particular, a robust statistical weighting technique, is developed. It is applied to an echelle spectrum of resolution 15 km s$^{-1}$ of PKS 1937-101 with z...
1994-10-05
2009-10-22
[ "astro-ph" ]
Yihu Fang and Arlin Crotts
astro-ph/9410019
An Optical Corrector Design That Allows a Fixed Telescope to Access a Large Region of the Sky
We discuss a family of two-mirror correctors that can greatly extend the field accessible to a fixed telescope such as a liquid mirror telescope. The performance of the corrector is remarkable since it gives excellent images in patches contained within a field greater than 45 degrees. We argue that this performance mak...
1994-10-05
2007-05-23
[ "astro-ph" ]
E.F. Borra, G. Moretto, and M. Wang
astro-ph/9410018
The Stromlo-APM Redshift Survey II. Variation of Galaxy Clustering with Morphology and Luminosity
We present clustering measurements for samples of galaxies selected by morphological type and luminosity from the recently completed Stromlo-APM Redshift Survey. Early type galaxies are clustered more strongly by a factor 3.5--5.5, than late type galaxies. Low-luminosity galaxies are clustered more weakly by a factor o...
1994-10-05
2009-10-22
[ "astro-ph" ]
J.Loveday, S.J.Maddox, G.Efstathiou and B.A.Peterson
astro-ph/9410015
Variable Stars in the Field of the Open Cluster NGC 7789
Fifteen variable stars have been discovered during four nights of monitoring of NGC 7789. It was possible to determine periods for ten of these variables. Seven objects are W UMa-type binaries, in this number five are members of the cluster. Among the remaining variables, there are three further close binaries, one del...
1994-10-05
2007-05-23
[ "astro-ph" ]
K. Jahn, J. Kaluzny, and S. M. Rucinski
astro-ph/9410016
A case for a baryonic dark halo
Recent observations of microlensing events in the Large Magellanic Cloud by the MACHO and EROS collaborations suggest that an important fraction of the galactic halo is in the form of Massive Halo Objects (MHO) with mass $\sim 0.1 M_{\odot}$. We outline a scenario in which dark clusters of MHO with mass $\sim 0.1 M_{\o...
1994-10-05
2009-10-22
[ "astro-ph" ]
F. De Paolis, G. Ingrosso, Ph. Jetzer and M. Roncadelli
astro-ph/9410017
A Potential Cyclotron Line Signature in Low Luminosity X-Ray Sources
Estimates indicate there may be $\simgreat 10^3$ low luminosity X-ray pulsars ($L \simless 10^{34} \rom{erg\;s^{-1}}$) in the Galaxy undergoing ``low-state'' wind accretion in Be/X-ray binary systems, and $\sim 10^8-10^9$ isolated neutron stars which may be accreting directly from the interstellar medium. Despite their...
1994-10-05
2009-10-22
[ "astro-ph" ]
Robert W. Nelson, John C.L. Wang, E.E. Salpeter, and Ira Wasserman
astro-ph/9410014
Influence of Cooling Flow and Galactic Motion on the Iron Distribution in Clusters of Galaxies
Iron abundance distribution is now known for 12 clusters of galaxies. For some clusters (e.g. Centaurus) the observed abundance increases toward the cluster center, while for the others (e.g. Coma and Hydra-A) no significant inhomogeneity was observed. In order to understand this difference, we investigate the influenc...
1994-10-05
2009-10-22
[ "astro-ph" ]
Yutaka Fujita and Hideo Kodama
astro-ph/9410013
Missing Opacity in the Atmospheric Models of Red Giants
Synthetic spectra of Arcturus computed with the latest theoretical stellar atmospheres disagree strongly with both the spectral energy distribution and with the spectroscopic data for $\lambda < 4000$ \AA , even though the stellar parameters are well constrained. We find that the discrepancy can be removed by adding a ...
1994-10-04
2009-10-22
[ "astro-ph" ]
C. I. Short and J. B. Lester
astro-ph/9410012
Black holes in galactic nuclei: the dynamical evidence
The dynamical evidence for black holes (BHs) in galactic nuclei is reviewed, with emphasis on recent improvements in spatial resolution, methods for analyzing galaxy spectra and dynamical modeling. M31, M32 and M87 are discussed in some detail.
1994-10-04
2007-05-23
[ "astro-ph" ]
Roeland P. van der Marel
astro-ph/9410010
Yet Another Paper on Sn1987a: Large Angle Oscillations, and the Electron Neutrino Mass
We supplement \ML methods with a \MC simulation to re-investigate the SN1987A neutrino burst detection by the IMB and Kamiokande experiments. The detector simulations include background in the the latter and ``dead-time'' in the former. We consider simple neutrinosphere cooling models, explored previously in the litera...
1994-10-04
2008-11-26
[ "astro-ph", "hep-ph" ]
Peter J. Kernan and Lawrence M. Krauss
astro-ph/9410011
Thick Penumbra in a Magnetostatic Sunspot Model
The conjecture that energy transport in sunspot penumbrae occurs through convection by an interchange of magnetic flux tubes is used in order to construct a magnetostatic model for a deep penumbra which is part of a global sunspot model. The model describes an overall mechanical equilibrium between the three stratifica...
1994-10-04
2008-02-03
[ "astro-ph" ]
K. Jahn and H.U. Schmidt
astro-ph/9410009
Hydrodynamic Simulations of Galaxy Formation. I. Dissipation and the Maximum Mass of Galaxies
We describe an accurate, one-dimensional, spherically symmetric, Lagrangian hydrodynamics/gravity code, designed to study the effects of radiative cooling and photo-ionization on the formation of protogalaxies. The code can treat an arbitrary number of fluid shells (representing baryons) and collisionless shells (repre...
1994-10-04
2009-10-22
[ "astro-ph" ]
A.A. Thoul and D.H. Weinberg
astro-ph/9410003
Electromgnetic-gravitational cross-sections in external elctromagnetic fields
The classical processes: the conversion of photons into gravitons in the static electromagnetic fields are considered by using Feynman perturbation techniques. The differential cross sections are presented for the conversion in the electric field of the flat condesor and the magnetic field of the selenoid. A numerical ...
1994-10-03
2008-11-26
[ "astro-ph" ]
Hoang Ngoc Long, Dang Van Soa, and Tuan A. Tran
astro-ph/9410008
Liquid Mirrors: A Review
The surface of a spinning liquid takes the shape of a paraboloid that can be used as a reflecting mirror. This very old and nearly forgotten concept has recently been revived and I review its present status. Extensive interferometric tests of liquid mirrors (the largest one having a diameter of 2.5-meters ) show excell...
1994-10-03
2007-05-23
[ "astro-ph" ]
Ermanno F. Borra
astro-ph/9410004
Simulations of the Microwave Sky and of its ``Observations''
Here follows a preliminary report on the construction of fake millimeter and sub-millimeter skies, as observed by virtual instruments, e.g. the COBRA/SAMBA mission, using theoretical modeling and data extrapolations. Our goal is to create maps as realistic as possible of the relevant physical contributions which may co...
1994-10-03
2009-10-22
[ "astro-ph" ]
F.R. Bouchet, R. Gispert, N. Aghanim, J.R. Bond, A. De Luca, E. Hivon, and B. Maffei
astro-ph/9410002
Stellar Mass Loss-Driven Wind Models of Elliptical Galaxies?
Recent claims in the literature (Bressan, Chiosi & Fagotto 1994) that the epoch describing the onset of galactic winds in spheroidal star systems has been severely overestimated in the past, due to the neglect of energy deposited in the interstellar medium from stellar winds, is evaluated in the light of a more conserv...
1994-10-03
2016-06-08
[ "astro-ph" ]
Brad K. Gibson
astro-ph/9410001
Newtonian Evolution of the Weyl Tensor
In an interesting recent paper on the growth of inhomogeneity through the effect of gravity [1], Bertschinger and Hamilton derive equations for the electric and magnetic parts of the Weyl tensor for cold dust for both General Relativity and Newtonian theory. Their conclusion is that both in General Relativity and in Ne...
1994-10-03
2009-10-22
[ "astro-ph", "gr-qc" ]
G.F.R. Ellis and P.K.S. Dunsby
astro-ph/9410007
Large Scale Baryon Isocurvature Inhomogeneities
Big bang nucleosynthesis constraints on baryon isocurvature perturbations are determined. A simple model ignoring the effects of the scale of the perturbations is first reviewed. This model is then extended to test the claim that large amplitude perturbations will collapse, forming compact objects and preventing their ...
1994-10-03
2009-09-25
[ "astro-ph" ]
Craig J. Copi, Keith A. Olive, and David N. Schramm
astro-ph/9410006
Major axis kinematics of 15 early-type galaxies in the Fornax cluster
Major axis rotation curves and velocity dispersions profiles, extending out to about one effective radius, are presented for 15 ellipticals and S0's out of the photometric sample of Fornax cluster galaxies studied by Caon \etal\ (1994). A brief description of the spectroscopic and photometric characteristics of each ga...
1994-10-03
2007-05-23
[ "astro-ph" ]
M.D'Onofrio, S.R.Zaggia, G.Longo, N.Caon, and M.Capaccioli
astro-ph/9410005
Integrability Conditions for Irrotational Dust with a Purely Electric Weyl Tensor: A Tetrad Analysis
All spacetimes for an irrotational collisionless fluid with a purely electric Weyl tensor, with spacetime curvature determined by the exact Einstein field equations, are shown to be integrable. These solutions include the relativistic generalisations of the Zeldovich solutions of Newtonian theory. Thus our result shows...
1994-10-03
2009-10-22
[ "astro-ph", "gr-qc" ]
W.M. Lesame, P.K.S. Dunsby and G.F.R. Ellis
astro-ph/9409095
FeII and FeI emission in IRAS 07598+6508 and PHL 1092
One of the puzzles in understanding the spectra of active galactic nuclei (AGN) is the origin of the FeII emission. FeI emission, if present, will help reveal the physical conditions of the emitting gas. In an attempt to verify the presence of FeI lines, high S/N spectra of two FeII-strong quasars, IRAS 07598-6508 and ...
1994-10-01
2009-10-22
[ "astro-ph" ]
John Kwan, Fu-zhen Cheng, Li-Zhi Fang, Wei Zheng and Jian Ge
astro-ph/9409094
Studying Structure Formation With Large Galaxy Redshift Surveys
I outline the connections between some of the most widely used statistical measures of galaxy clustering and the fundamental issues in the theory of structure formation. I devote particular attention to the problem of biasing, i.e. to a possible difference between the distribution of galaxies and the distribution of ma...
1994-09-30
2007-05-23
[ "astro-ph" ]
David H. Weinberg
astro-ph/9409081
Moment Analysis Applied to LMC Star Clusters
Statistical moment-based ellipse fitting was performed on observations of Large Magellanic Cloud clusters, confirming that trends are evident in their position angles and ellipticities, as had been reported in the literature. Artificial cluster images with known parameters were generated, and subjected to the same anal...
1994-09-29
2015-06-24
[ "astro-ph" ]
Timothy Banks, R.J. Dodd and D.J. Sullivan
astro-ph/9409084
Globular Clusters in the Magellanic Clouds.I:BV CCD-Photometry for 11 Clusters
We present BV CCD-data for 11 intermediate-age LMC clusters; the main conclusions are: 1. in the (V_to, V_cl,m) and (V-to, (V_to-V_cl,m)) planes the models yield a good overall description of the data; 2. with the current sample, it is impossible to firmly choose between "classical" and "overshooting" models; 3. the se...
1994-09-29
2019-08-17
[ "astro-ph" ]
C.E. Corsi, R. Buonanno, F. Fusi Pecci, F.R. Ferraro, V. Testa, L. Greggio
astro-ph/9409089
Magnitude Offset between Lensed Stars and Observed Stars - a New Probe of the Structure of the Galactic Bar
We propose a new method that can be used to constrain the properties of the Galactic bar (bulge). If the majority of the lensing objects are in the Galactic bar, then we predict a systematic offset in the apparent magnitude between lensed stars and all observed stars. Using OGLE color-magnitude diagram data we model th...
1994-09-29
2009-10-22
[ "astro-ph" ]
K. Z. Stanek (Princeton University Observatory)
astro-ph/9409085
Globular Clusters in the Magellanic Clouds.II: IR-Array Photometry for 12 Globulars and Contributions to the Integrated Cluster Light
We report the results of the observations in the JHK bands of 12 globular clusters in the LMC, and present CMDs down to K=16 for about 450 stars. We merge the data with the BV ones presented in paper I and use the merged data to study the evolution of integrated magnitudes and colours of SSPs. We find that the AGB cont...
1994-09-29
2015-06-24
[ "astro-ph" ]
F.R. Ferraro, F. Fusi Pecci, V. Testa, L. Greggio, R. Buonanno, C.E. Corsi, C.M. Terndrup H. Zinnecker
astro-ph/9409092
Mount Pinatubo and Atmospheric Extinction at Mount John University Observatory 1987-94
Atmospheric extinction in the V passband at Mount John University Observatory, New Zealand, from 1987-94 is presented and the effect of the 1991 Mount Pinatubo volcanic eruption is discussed.
1994-09-29
2007-05-23
[ "astro-ph" ]
M.C. Forbes, T. Banks, D.J. Sullivan, R.J. Dodd, A.C. Gilmore and P.M. Kilmartin
astro-ph/9409083
A Technique Fof Determining the Extragalactic Distance Scale
We propose a method of distance determination based on the internal structure and dynamics of disk galaxies. The method relies on the universal luminosity profile of a stellar disk represented by an exponential law. Calibrating nearby galaxies with known distances, it is found that the scale length of the disk is tight...
1994-09-29
2009-10-22
[ "astro-ph" ]
Masashi Chiba & Yuzuru Yoshii
astro-ph/9409090
Dense Stellar Cores in Merger Remnants
We use numerical models which include star formation to analyze the mass profiles of remnants formed by mergers of disk galaxies. During a merger, dissipation in gas and ensuing star formation leave behind a dense stellar core in the remnant. Rather than joining smoothly onto a de Vaucouleurs profile, the starburst pop...
1994-09-29
2007-05-23
[ "astro-ph" ]
Chris Mihos and Lars Hernquist
astro-ph/9409093
When Does the Richardson-Lucy Deconvolution Converge ?
(\rl = Richardson-Lucy) We propose a simulation-based bootstrap method to access global significance levels of deconvolution models in the \rl and other iterative restoration algorithms that converge locally. These significance levels allow one to check at each iterative step how good the model is and when iterations c...
1994-09-29
2007-05-23
[ "astro-ph" ]
Hongguang Bi, Gerhard Boerner (MPI fuer Astrophysik, GERMANY)
astro-ph/9409091
The Evolution of X-Ray Clusters in a Cold Plus Hot Dark Matter Universe
We present the first self-consistently computed results on the evolution of X-ray properties of galaxy clusters in a Cold + Hot Dark Matter (CHDM) model. We have performed a hydrodynamic plus N-body simulation for the COBE-compatible CHDM model with standard mass components: Omega(hot) = 0.3, Omega(cold) = 0.6 and Omeg...
1994-09-29
2009-10-22
[ "astro-ph" ]
Greg L. Bryan, Anatoly Klypin, Chris Loken, Michael L. Norman, Jack O. Burns
astro-ph/9409082
Can globular clusters be as young as 10 Gyr?--The Uncertainties in the Age of Globular Clusters from Their Helium Abundance and Mass Loss
The age of globular clusters inferred from observations depends sensitively on assumptions such as the initial helium abundance and the mass loss rate. A high helium abundance (e.g., $Y\approx$0.28), as well as an inclusion of helium diffusion and oxygen-enhancement in stellar models, can lower the current age estimate...
1994-09-29
2008-02-03
[ "astro-ph" ]
Xiangdong Shi
astro-ph/9409088
Lyman Alpha Absorption and Tidal Debris
The origin and evolution of structure in the Universe is one of the major questions occupying astronomers today. An understanding of the Lyalpha absorbers seen in QSO spectra is an important part of this program since such absorbers can be traced back to very high redshifts. Their mere existence places constraints on t...
1994-09-29
2007-05-23
[ "astro-ph" ]
Simon L. Morris
astro-ph/9409086
Fokker-Planck models of NGC 6397 -- A. The modeling
This is the first of two papers presenting a detailed examination of Fokker-Planck models for the globular cluster NGC 6397. I show that these models provide a good match to observations of the surface density profile, mass functions at three radii and the velocity dispersion profile. The constraint of requiring the be...
1994-09-29
2007-05-23
[ "astro-ph" ]
G.A. Drukier
astro-ph/9409087
Fokker-Planck models of NGC 6397 -- B. The globular cluster
This is the second of two papers presenting a detailed examination of Fokker-Planck models for the globular cluster NGC 6397 and is concerned with extracting information on the cluster from the models. The models give a current cluster mass of $6.6\pm 0.5\times 10^4 \Msolar$ of which about 2500 \Msolar\ is in neutron s...
1994-09-29
2007-05-23
[ "astro-ph" ]
G.A. Drukier
astro-ph/9409076
The Infrared Band Strengths of H2o, Co and Co2 in Laboratory Simulations of Astrophysical Ice Mixtures
Infrared spectroscopic observations toward objects obscured by dense cloud material show that H$_2$O, CO and, likely, CO$_2$ are important constituents of interstellar ice mantles. In order to accurately calculate the column densities of these molecules, it is important to have good measurements of their infrared band ...
1994-09-28
2008-02-03
[ "astro-ph" ]
P.A. Gerakines, W.A. Schutte, J.M. Greenberg, and Ewine F. van Dishoeck
astro-ph/9409073
Evolution of Galactic Nuclei with 10 $M_\odot$ Black Holes
A star with main sequence mass greater than $25\sim 30\msun$ may collapse to a black hole of about 10 $\msun$ at the final stage of the evolution. About an order of 1\% of stellar mass is likely to be in form of such black holes in galaxies. We have examined the dynamics of two-component stellar systems composed of 0.7...
1994-09-28
2015-06-24
[ "astro-ph" ]
Hyung Mok Lee
astro-ph/9409075
The Observed Properties of High-Redshift Cluster Galaxies
We use the semi-analytic models of galaxy formation developed by Kauffmann, White \& Guiderdoni to generate predictions for the observed properties of cluster and group galaxies at redshifts between 0 and 0.6. We examine four sets of cosmological initial conditions: low-density CDM models with and without cosmological ...
1994-09-28
2015-06-24
[ "astro-ph" ]
Guinevere Kauffmann
astro-ph/9409078
Preliminary Results from the ESO Slice Project (ESP)
We present the first results of a galaxy redshift survey, ESO Slice Project (ESP), we are accomplishing as an ESO Key-Project over about 30 square degrees in a region near the South Galactic Pole. The limiting magnitude is b_J = 19.4. Observations have been almost completed and about 90% of the data obtained so far has...
1994-09-28
2007-05-23
[ "astro-ph" ]
G.Vettolani, E.Zucca, A.Cappi, R.Merighi, M.Mignoli, G.Stirpe, G.Zamorani, H.MacGillivray, C.Collins, C.Balkowski, J.Alimi, A.Blanchard, V.Cayatte, P.Felenbok, S.Maurogordato, D.Proust, G.Chincarini, L.Guzzo, D.Maccagni, R.Scaramella, M.Ramella
astro-ph/9409077
Trends in Large Scale Structure Observations and the Likelihood of Early Reionization
With the imminent promise of constraints on the epoch of reionization from observations of microwave background anisotropies, the question of whether or not the standard Cold Dark Matter (CDM) model permits early reionization has been subjected to detailed investigation by various authors, with the conclusion that reio...
1994-09-28
2015-06-24
[ "astro-ph" ]
Andrew R Liddle and David H Lyth
astro-ph/9409074
Mixed Cold-Hot Dark Matter Model with Falling and Quasi-Flat Initial Perturbation Spectra
The mixed cold-hot dark matter cosmological model (CHDM) with $\Omega_{tot}=1$ and a falling power-law initial spectrum of Gaussian adiabatic perturbations ($n>1$) is tested using recent obserbational data. It is shown that its fit to the data becomes worse with the growth of $n-1$, and may be considered as unreasonabl...
1994-09-28
2009-10-22
[ "astro-ph" ]
Dmitri Pogosyan and Alexei Starobinsky
astro-ph/9409079
Dwarf Elliptical Galaxies
Dwarf elliptical (dE) galaxies, with blue absolute magnitudes typically fainter than $M_B = -16$, are the most numerous type of galaxy in the nearby universe. Tremendous advances have been made over the past several years in delineating the properties of both Local Group satellite dE's and the large dE populations of n...
1994-09-28
2009-10-22
[ "astro-ph" ]
Henry C. Ferguson and Bruno Binggeli
astro-ph/9409080
The Optical Gravitational Lensing Experiment. Deep Photometry of the Sagittarius Dwarf Spheroidal Galaxy
We present deep CCD photometry of a field in the newly discovered dwarf spheroidal galaxy in Sagittarius (hereafter Sgr), and of a nearby control field. These data (totaling ~3.5 hrs exposure time in V and I) were used to produce color-magnitude (CM) diagrams reaching I ~ 22.3 in both fields. After statistically removi...
1994-09-28
2009-10-22
[ "astro-ph" ]
Mario Mateo, A. Udalski, M. Szymanski, J. Kaluzny, M. Kubiak, and W. Krzeminski
astro-ph/9409070
Exponential Growth of Distance between Nearby Rays due to Multiple Gravitational Scatterings
We give an estimate of the relative error in the angular measurement of observations for high redshift objects induced by gravitational scatterings (lensing). Gunn (1967) concluded that the gravitational scatterings by galaxies induce the relative error of a few percent in the observations for objects at $z=1$. This es...
1994-09-27
2009-10-22
[ "astro-ph" ]
Toshiyuki Fukushige and Junichiro Makino
astro-ph/9409071
The Contribution of Low Surface-Brightness Galaxies to Faint Galaxy Counts
Low Surface-Brightness (LSB) galaxies are severely underrepresented in surveys used to define the local luminosity function (LF), but could it in principle be detected in deep surveys. To explore the possible contribution of such objects to faint galaxy counts, we construct catalogs of simulated non-evolving galaxies d...
1994-09-27
2009-10-22
[ "astro-ph" ]
Henry C. Ferguson and Stacy S. McGaugh
astro-ph/9409067
The contribution of AGNs to the X-ray background
We report the results of a detailed analysis of the contribution of various classes of AGNs to the extragalactic X-ray background (XRB). The model is based on the unification schemes of AGNs and on their related X-ray spectral properties in the light of recent observational results. The integrated emission from AGNs, w...
1994-09-27
2011-05-23
[ "astro-ph" ]
A. Comastri, G. Setti, G. Zamorani, G. Hasinger
astro-ph/9409066
The Very Red Halo of the cD Galaxy in A3284
We present deep CCD surface photometry in the Gunn g, r, i system and spectroscopy of the cD galaxy at the centre of the cluster A3284 at z = 0.15. The brightness profile of the galaxy has been tracked up to 40 arcsec (142 kpc) from the centre, and down to 26 mag/arcsec^2. The core and halo components in the galaxy hav...
1994-09-27
2007-05-23
[ "astro-ph" ]
E. Molinari, A. Buzzoni, G. Chincarini (M.D. Pedrana Osservatorio Astronomico di Brera)
astro-ph/9409068
The variable ROSAT X-ray spectrum of the BL Lac 0716+714
The BL Lac object 0716+714 is a powerful flat spectrum radio source detected by CGRO-EGRET at $\gamma$-ray energies. It has been observed for about 21000 s over two days by the X-ray telescope onboard the ROSAT satellite and strong flux and spectral variations have been detected. In the time scale of two days the sourc...
1994-09-27
2015-06-24
[ "astro-ph" ]
M. Cappi, A. Comastri, S. Molendi, G.G.C. Palumbo, R. Della Ceca, T. Maccacaro
astro-ph/9409072
An Infrared Cutoff Revealed by the Two Years of COBE-DMR Observations of Cosmic Temperature Fluctuations
We show that a good fitting to the first two years of {\it COBE}-DMR observations of the two-point angular correlation function of CBR temperature is given by models with a non-zero infrared cutoff $k_{min}$ in the spectrum of the primordial density perturbations. If this cutoff comes from the finiteness of the univers...
1994-09-27
2009-10-22
[ "astro-ph" ]
Yi-Peng Jing and Li-Zhi Fang
astro-ph/9409069
The Effect of Gravitational Scattering on the Anisotropy of the Cosmic Background Radiation
The homogeneity of the cosmic microwave background radiation (CBR) is one of the most severe constraint for theories of the structure formation in the universe. We investigated the effect of the gravitational scattering (lensing) of galaxies, clusters of galaxies, and superclusters on the anisotropy of the CBR by numer...
1994-09-27
2009-10-22
[ "astro-ph" ]
Toshiyuki Fukushige, Junichiro Makino, and Toshikazu Ebisuzaki
astro-ph/9409064
Non-Lte Effects on be and B Abundance Determinations in Cool Stars
We discuss the nature of non-LTE effects affecting abundance analysis of cool stars. The departures from LTE of importance for the B I lines in solar-type stars are described and some new results are presented. Boron abundances derived under the LTE assumption have significant systematic errors, especially for metal-po...
1994-09-26
2007-05-23
[ "astro-ph" ]
Dan Kiselman & Mats Carlsson
astro-ph/9409065
A New Macho Search Strategy
I propose a radical revision in the search strategy for Massive Compact Objects (Machos) toward the Galactic bulge: monitor the entire $\sim 300$ square deg of the bulge and tune the search primarily to microlensing events of bright $M_V\lsim 2$ stars. By employing a small second telescope to follow up the events detec...
1994-09-26
2009-10-22
[ "astro-ph" ]
Andrew Gould
astro-ph/9409063
Cluster lens reconstruction using only observed local data
The reconstruction of the density profile in clusters of galaxies from the distortion of the images of faint background galaxies is reconsidered. The inversion formula of Kaiser \& Squires is known to provide a quantitative way to perform this reconstruction; however, the practical application of this formula faces two...
1994-09-24
2007-05-23
[ "astro-ph" ]
Peter Schneider
astro-ph/9409059
On the Mathematical Character of the Relativistic Transfer Moment Equations
General--relativistic, frequency--dependent radiative transfer in spherical, differentially--moving media is considered. In particular we investigate the character of the differential operator defined by the first two moment equations in the stationary case. We prove that the moment equations form a hyperbolic system w...
1994-09-23
2015-06-24
[ "astro-ph" ]
R. Turolla, L. Zampieri and L. Nobili
astro-ph/9409060
The Homogeneous Bright Quasar Survey and the Quasar Evolution in the Optical, X and Radio Bands
The present status of the ESO key-programme ``A Homogeneous Bright QSO Survey'' is described together with the first results concerning the QSO counts and the optical luminosity function. The related analysis of the evolution of the radio and X-ray selected QSOs is presented.
1994-09-23
2007-05-23
[ "astro-ph" ]
S. Cristiani and F. La Franca
astro-ph/9409061
Galaxy Evolution from QSO Absorption--Selected Samples
We present results of surveys for high redshift field galaxies selected by their having produced detectable absorption in the spectra of background QSOs. Such surveys, in essence selected by gas cross-section rather than by flux density, are almost completely independent of the conventional magnitude--limited redshift ...
1994-09-23
2007-05-23
[ "astro-ph" ]
C. Steidel (MIT) and M. Dickinson (STScI)
astro-ph/9409062
Hierarchical correlations in models of galaxy clustering
We present a comparison of the predictions of perturbation theory for the hierarchical J-order correlation amplitudes $S_J=\xibar_J/\xibar_2^{J-1}$, $J=3-10$, with the results of large numerical simulations of gravitational clustering. We consider two different initial power spectra of density fluctuations, one being f...
1994-09-23
2016-06-08
[ "astro-ph" ]
E. Gaztanaga & C.M. Baugh
astro-ph/9409055
Hypersurface-Invariant Approach to Cosmological Perturbations
Using Hamilton-Jacobi theory, we develop a formalism for solving semi-classical cosmological perturbations which does not require an explicit choice of time-hypersurface. The Hamilton-Jacobi equation for gravity interacting with matter (either a scalar or dust field) is solved by making an Ansatz which includes all ter...
1994-09-22
2010-11-01
[ "astro-ph", "gr-qc", "hep-ph" ]
D.S. Salopek and J.M. Stewart
astro-ph/9409056
Binary-Binary Interactions and the Formation of the PSR B1620-26 Triple System in M4
The hierarchical triple system containing the millisecond pulsar PSR B1620-26 in M4 is the first triple star system ever detected in a globular cluster. Such systems should form in globular clusters as a result of dynamical interactions between binaries. We propose that the triple system containing PSR B1620-26 formed ...
1994-09-22
2009-10-22
[ "astro-ph" ]
F. A. Rasio, S. McMillan, and P. Hut
astro-ph/9409057
Self-Lensing By Binaries
Lensing of one member of a binary by its companion is studied for several classes of binaries. For binaries in which at least one member is an ordinary (non-compact) star, the optical depths to lensing is extremely low, $\tau\lsim v_\esc^4/c^4\sim 10^{-11}$. Here $v_\esc$ is the escape velocity from the component with ...
1994-09-22
2009-10-22
[ "astro-ph" ]
Andrew Gould
astro-ph/9409054
The Evolution of the Optical Galaxy Luminosity Function -
The optical luminosity function is a fundamental characterization of the galaxy population. A combination of earlier redshift surveys with two new surveys allows the first accurate determination of the evolution of the luminosity function with redshift, and reveals a marked steepening of the faint end slope. This effec...
1994-09-22
2007-05-23
[ "astro-ph" ]
Matthew Colless
astro-ph/9409053
Observational constraints on the neutron star mass distribution
Radio observations of neutron star binary pulsar systems have constrained strongly the masses of eight neutron stars. Assuming neutron star masses are uniformly distributed between lower and upper bounds $m_l$ and $m_u$, the observations determine with 95\% confidence that $1.01 < m_l/\text{M}_\odot < 1.34$ and $1.43 <...
1994-09-22
2009-01-23
[ "astro-ph", "gr-qc" ]
L. S. Finn
astro-ph/9409058
Hydra: An Adaptive--Mesh Implementation of PPPM--SPH
We present an implementation of Smoothed Particle Hydrodynamics (SPH) in an adaptive-mesh PPPM algorithm. The code evolves a mixture of purely gravitational particles and gas particles. The code retains the desirable properties of previous PPPM--SPH implementations; speed under light clustering, naturally periodic boun...
1994-09-22
2009-10-22
[ "astro-ph" ]
H.M.P. Couchman, P.A. Thomas and F.R. Pearce
astro-ph/9409052
A Count Probability Cookbook: Spurious Effects and the Scaling Model
We study the errors brought by finite volume effects and dilution effects on the practical determination of the count probability distribution function P_N(n,L), which is the probability of having N objects in a cell of volume L^3 for a set of average number density n. Dilution effects are particularly relevant to the ...
1994-09-21
2009-10-22
[ "astro-ph" ]
S. Colombi, F.R. Bouchet, R. Schaeffer
astro-ph/9409051
Natural Wormholes as Gravitational Lenses
Visser has suggested traversable 3-dimensional wormholes that could plausibly form naturally during Big Bang inflation. A wormhole mouth embedded in high mass density might accrete mass, giving the other mouth a net *negative* mass of unusual gravitational properties. The lensing of such a gravitationally negative anom...
1994-09-20
2009-10-22
[ "astro-ph", "gr-qc" ]
John G. Cramer, Robert L. Forward, Michael S. Morris, Matt Visser, Gregory Benford, and Geoffrey A. Landis
astro-ph/9409050
Chaos and Noise in Galactic Potentials
ABBREVIATED ABSTRACT: This paper summarises an investigation of the effects of weak friction and noise in time-independent, nonintegrable potentials which admit both regular and stochastic orbits. The aim is to understand the qualitative effects of internal and external irregularities associated, e.g., with discretenes...
1994-09-19
2009-10-22
[ "astro-ph", "chao-dyn", "gr-qc", "nlin.CD" ]
Salman Habib, Henry E. Kandrup, and M. Elaine Mahon
astro-ph/9409049
Reverberation by a Relativistic Accretion Disk
We calculate the response of a line emitted from a relativistic accretion disk to a continuum variation of the central illuminating source. This model might be relevant to the very broad and sometimes redshifted emission lines which have been observed at optical and X-ray energies in Active Galactic Nuclei and X-ray bi...
1994-09-19
2015-06-24
[ "astro-ph" ]
Sergio Campana and Luigi Stella (Osservatorio Astronomico di Brera, Via Brera 28, 20121 Milano, Italy)
astro-ph/9409048
On the propagation of sound waves in a stellar wind traversed by periodic strong shocks
It has been claimed that in stellar winds traversed by strong shocks the mechanism for driving the wind by sound wave pressure cannot operate because sound waves cannot propagate past the shocks. It is shown here that sound waves can propagate through shocks in one direction and that this is a sufficient condition for ...
1994-09-19
2007-05-23
[ "astro-ph" ]
F.P. Pijpers
astro-ph/9409046
Testing Cosmogonic Models with Gravitational Lensing
Gravitational lensing provides a strict test of cosmogonic models. Detailed numerical propagation of light rays through a universe having a distribution of inhomogeneities derived from the standard CDM (cold dark matter) scenario with the aid of massive, fully nonlinear computer simulations is used to test the model. I...
1994-09-16
2010-12-13
[ "astro-ph" ]
Joachim Wambsganss, Renyue Cen, Jeremiah P. Ostriker and Edwin L. Turner
astro-ph/9409047
Association of Unidentified, Low Latitude EGRET Sources with Supernova Remnants
We propose that some of the unidentified Galactic plane (-10 degrees < b < 10 degrees) sources listed in the first EGRET catalog (Fichtel et al. 1994) are associated with nearby supernova remnants. The probability that the association of strong EGRET sources with supernova remnants is due to chance alignment is found t...
1994-09-16
2007-05-23
[ "astro-ph" ]
S. J. Sturner and C. D. Dermer
astro-ph/9409044
ROSAT Observations of the Flare Star CC Eri
The flare/spotted spectroscopic binary star CC Eri was observed with the Position Sensitive Proportional Counter (PSPC) on the X-ray satellite ROSAT on 1990 July 9-11 and 1992 January 26-27. During the observations, the source was variable on time scales from a few minutes to several hours, with the X-ray (0.2-2 keV) l...
1994-09-16
2015-06-24
[ "astro-ph" ]
H. C. Pan and C. Jordan
astro-ph/9409045
A large amplitude flaring dMe star in the 1978 October 6B $\gamma$-ray burst error box
Spectroscopic observations provide evidence that the optical transient object observed in 1966 on archival plates of Sonneberg Observatory is a B=18.5 dMe star. For an assumed flare duration of 40 min. (or longer) the flare amplitude was $\bigtriangleup$m$_{B}$ $\approx$ 5.2 mag. If the recorded event was belonging to ...
1994-09-16
2009-10-22
[ "astro-ph" ]
J. Greiner, C. Motch
astro-ph/9409043
Angular two-point correlation functions for cosmological gamma-ray burst model
We compute the angular two-point correlation functions of the gamma-ray bursts at cosmological distances. Since the gamma-ray burst emission mechanism is not yet established, we simply assume that the gamma-ray burst sources are associated with high-redshift galaxies in some way. Then on the basis of several simple mod...
1994-09-16
2009-10-22
[ "astro-ph" ]
Shiho Kobayashi, Shin Sasaki, and Yasushi Suto
astro-ph/9409040
The Classification of M1-78
The published properties of M1-78 are discussed with the purpose to resolve the object's classification as either a planetary nebula or an ultracompact HII region. A classification as a planetary nebula is rejected primarily because of the high luminosity of the object, but because of the chemical composition and expan...
1994-09-15
2021-10-13
[ "astro-ph" ]
G. T. Gussie
astro-ph/9409042
Velocity Correlations of Galaxy Clusters
We determine the velocity correlation function, pairwise peculiar velocity difference, and root-mean-square pairwise peculiar velocity dispersion of rich clusters of galaxies, as a function of pair separation, for three cosmological models: Omega=1 and Omega=0.3 CDM, and Omega=0.3 PBI models (all flat and COBE-normaliz...
1994-09-15
2009-10-22
[ "astro-ph" ]
Renyue Cen, Neta A. Bahcall and Mirt Gramann (Princeton University Observatory, Princeton, NJ)
astro-ph/9409041
High frequency oscillations of Newton's constant induced by inflation
We examine the possibility that an epoch of inflationary expansion induces high-frequency oscillations of Newton's constant, $G$. The effect occurs because inflation can shift the expectation value of a non-minimally coupled, Brans-Dicke-like field away from the minimum of its effective potential. At some time after in...
1994-09-15
2009-09-25
[ "astro-ph", "gr-qc" ]
Clifford M. Will and Paul J. Steinhardt
astro-ph/9409034
Gravitational Microlensing Results from Macho
We provide a status report on our search for dark matter in our Galaxy in the form of massive compact halo objects (MACHOs), using gravitational microlensing of background stars. This search uses a very large CCD camera on the dedicated 1.27m telescope at Mt.~Stromlo, Australia, and has been taking data for 2 years. At...
1994-09-14
2009-10-22
[ "astro-ph" ]
W. Sutherland, C. Alcock, R. Allsman, T. Axelrod, D. Bennett, S. Chan, K. Cook, K. Freeman, K. Griest, S. Marshall, S. Perlmutter, B. Peterson, M. Pratt, P. Quinn, A. Rodgers, C. Stubbs
astro-ph/9409037
HST Observations of the Distant Cluster 0016+16: Quantitative Morphology of Confirmed Cluster Members
We present HST images of 24 confirmed members of the distant galaxy cluster Cl0016+16 at redshift 0.55. The Balmer-strong (``E+A'') and emission- line galaxies frequently show unusual visual morphology, implying that galaxian interactions produce ``active'' galaxies in moderate-redshift clusters. We use the image conce...
1994-09-14
2009-10-22
[ "astro-ph" ]
Gregory D. Wirth, David C. Koo, and Richard G. Kron
astro-ph/9409035
Emission Line Profiles from Self-Gravitating Thin Disks
We have constructed general relativistic models of a stationary, axially symmnetric, Keplerian thin disk around a rotating black hole. We computed profiles of a spectral line, emitted in the inner region of the disk. In our models we have taken into account also the self-gravity of the disk. The aim of this work is to ...
1994-09-14
2009-10-22
[ "astro-ph" ]
V. Karas, A. Lanza, and D. Vokrouhlicky
astro-ph/9409038
Real-space cosmic fields from redshift-space distributions: a Green function approach
We present a new method for reconstructing the cosmological density, peculiar velocity and peculiar gravitational potential on large scales from redshift data. We remove the distorting effects of line-of-sight peculiar motions by using the linear theory of gravitational instability, in which the potential is the soluti...
1994-09-14
2009-10-07
[ "astro-ph" ]
Max Tegmark, Benjamin Bromley
astro-ph/9409039
Phase-Transition Theory of Instabilities.I.Second-Harmonic Instability and Bifurcation Points
A free-energy minimization approach is used to address the secular & dynamical instabilities & the bifurcations along sequences of rotating, self-gravitating fluid and stellar systems. Our approach stems from the Landau-Ginzburg theory of phase transitions. We focus on the Maclaurin sequence of oblate spheroids & on th...
1994-09-14
2009-10-22
[ "astro-ph" ]
D.M. Christodoulou, D. Kazanas, I. Shlosman & J.E. Tohline
astro-ph/9409036
The Mass Spectrum Of Machos From Parallax Measurements
We demonstrate that by making satellite-based parallax measurements of Macho events, it is possible to distinguish disk from bulge Machos and to determine individual masses of disk Machos to an accuracy of $0.2$ in the log. This is at least a 3-fold improvement over what can be done without parallaxes, i.e., just from ...
1994-09-14
2009-10-22
[ "astro-ph" ]
Cheongho Han and Andrew Gould
astro-ph/9409031
Optimizing Observing Patterns in Cosmic Microwave Background Radiation Anisotropy Experiments
We consider several factors concerning the design of observing strategies in Cosmic Microwave Background (CMB) anisotropy experiments. First we consider the number of independent points on the sky one should observe given a fixed observing time. Given an assumed level of sky temperature fluctuations, $\sigma_{sky}$ and...
1994-09-13
2007-05-23
[ "astro-ph" ]
R.K. Schaefer and L. Piccirillo
astro-ph/9409032
The Gravitational Potential of the Bar in NGC 4314
We present near-infrared images of NGC 4314 in the $J$,$H$, and $K$ bands. Colors in these bands are constant across the bar of NGC 4314 indicating that the mass-to-light ratio is constant over much of the galaxy. We have developed an efficient procedure for mapping the gravitational potential of a non-axisymmetric gal...
1994-09-13
2009-10-22
[ "astro-ph" ]
A.C. Quillen, Jay. A. Frogel and Rosa A. Gonz'alez
astro-ph/9409027
A Spherical Harmonic Analysis of Redshift Space
We re-examine the effects of redshift space distortion in all-sky galaxy redshift surveys in the formalism of spherical harmonics. Within this framework we show how one can treat both the large-scale linear effects, and the small-scale nonlinear clustering, exactly to first order. The method also allows in principle a ...
1994-09-13
2015-06-24
[ "astro-ph" ]
A.F. Heavens and A.N. Taylor
astro-ph/9409033
An Estimate of the Gas Inflow Rate Along the Bar in NGC 7479
We present images of the barred galaxy NGC 7479 in the optical and near infrared broad--bands $B,V,R,J,H,K$, and images in H$\alpha$+[N II] and CO(J=1$\rightarrow$0) emission. The H$\alpha$ and CO emission in the bar are coincident and confined to narrow linear features that are offset from the center of the bar as obs...
1994-09-13
2009-10-22
[ "astro-ph" ]
A.C. Quillen, Jay. A. Frogel, Jeffrey D. P. Kenney, R. W. Pogge, and D. L. DePoy
astro-ph/9409030
Moments of the Cluster Distribution as a Test of Dark Matter Models
We estimate the variance and the skewness of the cluster distribution in several dark matter (DM) models. The cluster simulations are based on the Zel'dovich approximation, the low computational cost of which allows us to run 50 random realizations of each model. We compare our results with those coming from a similar ...
1994-09-13
2009-10-22
[ "astro-ph" ]
M.Plionis, S.Borgani, L.Moscardini, P.Coles
astro-ph/9409026
Implications on the Ionizing Background Radiation from HST Heii Gunn-Peterson Test
Recently, Jakobsen et al. reported that the HeII Gunn-Peterson optical depth is greater than 1.7 at $ z=3.3$. When we consider this observation combined with the HI Gunn-Peterson optical depths and the intensity of the UV background at high redshifts, we can put constraints on the spectrum of the UV background and the ...
1994-09-13
2008-02-03
[ "astro-ph" ]
Shin Sasaki and Fumio Takahara
astro-ph/9409029
A cosmological test with compact radio sources
The recent proposal by Kellermann (1993) to use the angular size/redshift relation of compact radio sources to obtain information on the value of cosmological parameters has provoked considerable discussion in the astronomical community. I present here a careful re-analysis of the angular size/redshift data of radio je...
1994-09-13
2011-05-23
[ "astro-ph" ]
R.Kayser
astro-ph/9409028
HST Images of Nearby Luminous Quasars
Strong upper limits are placed on the visual-band brightnesses of galactic hosts for four luminous, radio-quiet quasars with redshifts between $0.16$ and~$0.24$ that were studied with the HST's Wide Field/Planetary Camera-2. Typical upper limits on the luminosities of galactic hosts are about $1.4$ mag fainter than $L^...
1994-09-13
2009-10-22
[ "astro-ph" ]
John N. Bahcall, Sofia Kirhakos, and Donald P. Schneider