Showing 2002 · astro-phShow all

120 papers · 2 filters

astro-ph2002★ 49 cited

Discovery of a High-Redshift (z=0.96) Cluster of Galaxies Using a FIRST Wide-Angle Tailed Radio Source

Elizabeth L. Blanton, Michael D. Gregg, David J. Helfand +2

Using a combination of near-infrared and optical photometry, along with multi-object spectroscopy, we have confirmed the existence of a high-redshift cluster of galxies at z = 0.96…

astro-ph2002★ 3 cited

The LXeGRIT Compton Telescope Prototype: Current Status and Future Prospects

E. Aprile, A. Curioni, K. L. Giboni +7

LXeGRIT is the first prototype of a novel concept of Compton telescope, based on the complete 3-dimensional reconstruction of the sequence of interactions of individual gamma rays…

astro-ph2002★ 2 cited

On the Background Rate in the LXeGRIT Instrument during the 2000 Balloon Flight

A. Curioni, E. Aprile, K. L. Giboni +7

LXeGRIT is the first prototype of a novel Compton telescope for MeV gamma-ray astrophysics based on a Liquid Xenon Time Projection Chamber (LXeTPC), sensitive in the energy band of…

astro-ph2002★ 36 cited

On the Spiral Structure of NGC 2915 and Dark Matter

F. S. Masset, M. Bureau

NGC 2915 is a blue compact dwarf galaxy embedded in an extended, low surface brightness HI disk exhibiting a two-armed spiral structure and a central bar-like component. Commonly a…

astro-ph2002★ 69 cited

Superhumps in Cataclysmic Binaries. XXIII. V442 Ophiuchi and RX J1643.7+3402

Joseph Patterson, William Fenton, John Thorstensen +15

We report the results of long observing campaigns on two novalike variables: V442 Ophiuchi and RX J1643.7+3402. These stars have high-excitation spectra, complex line profiles sign…

astro-ph2002★ 91 cited

The Soft X-ray Spectrum from NGC 1068 Observed with LETGS on Chandra

A. C. Brinkman, J. S. Kaastra, R. L. J. van der Meer +5

Using the combined spectral and spatial resolving power of the Low Energy Transmission Grating (LETGS) on board Chandra, we obtain separate spectra from the bright central source o…

astro-ph2002★ 1 cited

The positron excess and supersymmetric dark matter

Edward A. Baltz, Joakim Edsjo, Katherine Freese +1

Using a new instrument, the HEAT collaboration has confirmed the excess of cosmic ray positrons that they first detected in 1994. We explore the possibility that this excess is due…

astro-ph2002★ 46 cited

DarkSUSY - A numerical package for supersymmetric dark matter calculations

Paolo Gondolo, Joakim Edsjo, Piero Ullio +3

The question of the nature of dark matter in the Universe remains one of the most outstanding unsolved problems in basic science. One of the best motivated particle physics candida…

astro-ph2002★ 28 cited

An Extreme Ultraviolet Explorer Atlas of Seyfert Galaxy Light Curves: Search for Periodicity

J. P. Halpern, K. M. Leighly, H. L. Marshall

The Deep Survey instrument on the Extreme Ultraviolet Explorer satellite (EUVE) obtained long, nearly continuous soft X-ray light curves of 5-33 days duration for 14 Seyfert galaxi…

astro-ph2002★ 84 cited

Monte Carlo reconstruction of the inflationary potential

Richard Easther, William H. Kinney

We present Monte Carlo reconstruction, a new method for ``inverting'' observational data to constrain the form of the scalar field potential responsible for inflation. This stochas…

astro-ph2002★ 402 cited

Gravitationally redshifted absorption lines in the X-ray burst spectra of a neutron star

J. Cottam, F. Paerels, M. Mendez

The fundamental properties of neutron stars provide a direct test of the equation of state of cold nuclear matter, a relationship between pressure and density that is determined by…

astro-ph2002★ 109 cited

XMM-Newton confirmation of Soft X-ray excess emission in clusters of galaxies - the discovery of O VII emission from an extended warm baryonic component

J. S. Kaastra, R. Lieu, T. Tamura +2

We investigate a sample of 14 clusters of galaxies observed with XMM-Newton in a search for soft X-ray excess emission. In five of these clusters a significant soft excess is evide…

astro-ph2002★ 401 cited

On the magnetic fields and particle acceleration in Cas A

Jacco Vink, J. Martin Laming

We investigate the non-thermal X-ray emission from Cas A. For the hard X-ray continuum we test the model proposed by Laming, which invokes bremsstrahlung from electrons accelerated…

astro-ph2002

Monte Carlo Methods for X-ray Dispersive Spectrometers

J. R. Peterson, J. G. Jernigan, S. M. Kahn

We discuss multivariate Monte Carlo methods appropriate for X-ray dispersive spectrometers. Dispersive spectrometers have many advantages for high resolution spectroscopy in the X-…

astro-ph2002★ 554 cited

High Resolution X-ray Spectroscopic Constraints on Cooling-Flow Models for Clusters of Galaxies

J. R. Peterson, S. M. Kahn, F. B. S. Paerels +5

We present high resolution X-ray spectra of 14 putative cooling-flow clusters of galaxies obtained with the Reflection Grating Spectrometer on XMM-Newton. The clusters in the sampl…

astro-ph2002

Deep Searches for Young Pulsars

Fernando Camilo

By 2000 there were only 10 established Galactic pulsar-supernova remnant associations. Two years later there are 16 such associations known. I discuss the work leading to this subs…

astro-ph2002★ 200 cited

The Formation of Stellar Clusters in Turbulent Molecular Clouds: Effects of the Equation of State

Yuexing Li, Ralf S. Klessen, Mordecai-Mark Mac Low

We study numerically the effect of varying the equation of state (EOS) on the formation of stellar clusters in turbulent molecular clouds. Our results show that the EOS plays an im…

astro-ph2002★ 102 cited

X-Ray Evidence for Flare Density Variations and Continual Chromospheric Evaporation in Proxima Centauri

Manuel Guedel, Marc Audard, Stephen L. Skinner +1

Using the XMM-Newton X-ray observatory to monitor the nearest star to the Sun, Proxima Centauri, we recorded the weakest X-ray flares on a magnetically active star ever observed. C…

astro-ph2002★ 29 cited

H2O Masers and Supersonic Turbulence

V. Strelnitski, J. Alexander, S. Gezari +3

We use unpublished and published VLBI results to investigate the geometry and the statistical properties of the velocity field traced by H2O masers in five galactic regions of star…

astro-ph2002

X-Ray Spectroscopy and Atomic Data

Ehud Behar, Steven M. Kahn

The Laboratory Astrophysics program employing the Lawrence Livermore National Laboratory (LLNL) Electron Beam Ion Trap (EBIT) has been providing useful atomic data in support of th…

astro-ph2002

Variable Stars in M31's Globular Clusters

David R. Alves, Alex Bergier, Arlin Crotts +1

This paper has been withdrawn.

astro-ph2002★ 196 cited

Nuclear Composition of Gamma-Ray Burst Fireballs

Andrei M. Beloborodov

We study three processes that shape the nuclear composition of GRB fireballs: (1) neutronization in the central engine, (2) nucleosynthesis in the fireball as it expands and cools,…

astro-ph2002

X-ray and Optical Studies of Millisecond Pulsars in 47 Tucanae

C. O. Heinke, J. E. Grindlay, P. D. Edmonds +1

Our Chandra X-ray observation of the globular cluster 47 Tuc clearly detected most of the 16 MSPs with precise radio positions, and indicates probable X-ray emission from the remai…

astro-ph2002★ 51 cited

The system parameters of DW Ursae Majoris

S. Araujo-Betancor, C. Knigge, K. S. Long +8

We present new constraints on the system parameters of the SW Sextantis star DW Ursae Majoris, based on ultraviolet (UV) eclipse observations with the Hubble Space Telescope. Our d…