7,250 research outputs found
The 4.5 +/- 0.5 Soft Gamma Repeaters in Review
Four Soft Gamma Repeaters (SGRs) have now been identified with certainty, and
a fifth has possibly been detected. I will review their X-ray and gamma-ray
properties in both outburst and quiescence. The magnetar model accounts fairly
well for the observations of SGR1806-20 and SGR1900+14, but data are still
lacking for SGR1627-41 and SGR0525-66. The locations of the SGRs with respect
to their supernova remnants suggest that they are high velocity objects.Comment: This review article will appear in various forms in the following
proceedings: 1. X-Ray Astronomy 1999 - Stellar Endpoints, AGN and the X-Ray
Background (Astrophysical Letters and Communications, 2000) 2. Proceedings of
the 5th Compton Symposium (AIP Press, 2000) 3. Proceedings of the 5th
Huntsville GRB Symposium (AIP Press, April 2000
Present and future gamma-ray burst experiments
Gamma-ray burst counterpart studies require small, prompt error boxes. Today,
there are several missions which can provide them: BeppoSAX, the Rossi X-Ray
Timing Explorer, and the 3rd Interplanetary Network. In the near future,
HETE-II, a possible extended Interplanetary Network, and INTEGRAL will operate
in this capacity. In the longer term future, a dedicated gamma-ray burst MIDEX
mission may fly. The capabilities of these missions are reviewed, comparing the
number of bursts, the rapidity of the localizations, and the error box sizes.Comment: Invited paper presented at the conference on Gamma-Ray Bursts in the
Afterglow Era, Rome, November 1998. To appear in Astronomy and Astrophysics
Supplement Serie
A Gamma-Ray Burst Bibliography, 1973-2001
On the average, 1.5 new publications on cosmic gamma-ray bursts enter the
literature every day. The total number now exceeds 5300. I describe here a
relatively complete bibliography which is on the web, and which can be made
available electronically in various formats.Comment: To appear in the proceedings of the conference on Gamma-Ray Burst and
Afterglow Astronomy 2001: A Workshop Celebrating the First Year of the HETE
Mission, to be published by AI
A Gamma-Ray Burst Bibliography, 1973-1999
On the average, one new publication on cosmic gamma-ray bursts enters the
literature every day. The total number now exceeds 4100. I present here a
complete bibliography which can be made available electronically to interested
parties.Comment: To appear in the proceedings of the 5th Huntsville GRB Symposium, AIP
press, April 200
The Ulysses Supplement to the BATSE 3B Catalog of Cosmic Gamma-Ray Bursts
We present Interplanetary Network localization information for 218 gamma-ray
bursts in the 3rd BATSE catalog, obtained by analyzing the arrival times of
these bursts at the Ulysses and Compton Gamma-Ray Observatory (CGRO)
spacecraft. For any given burst observed by these two spacecraft, arrival time
analysis (or "triangulation") results in an annulus of possible arrival
directions whose half-width varies between 7 arcseconds and 32 arcminutes,
depending on the intensity and time history of the burst, and the distance of
the Ulysses spacecraft from Earth. This annulus generally intersects the BATSE
error circle, resulting in an average reduction of the error box area of a
factor of 30.Comment: Accepted for publication in the Astrophysical Journal Supplemen
Fireball/Blastwave Model and Soft Gamma-ray Repeaters
Soft gamma-ray repeaters are at determined distances and their positions are
known accurately. If observed, afterglows from their soft gamma-ray bursts will
provide important clues to the study of the so called "classical gamma-ray
bursts". On applying the popular fireball/blastwave model of classical
gamma-ray bursts to soft gamma-ray repeaters, it is found that their X-ray and
optical afterglows are detectable. Monitoring of the three repeaters is
solicited.Comment: Already published in 1998 in "Chinese Physics Letters", replaced with
the published version. See astro-ph/0502452 for a more detailed versio
Gravitationally Lensed Gamma-Ray Bursts as Probes of Dark Compact Objects
If dark matter in the form of compact objects comprises a large fraction of
the mass of the universe, then gravitational lensing effects on gamma-ray
bursts are expected. We utilize BATSE and Ulysses data to search for lenses of
different mass ranges, which cause lensing in the milli, pico, and femto
regimes. Null results are used to set weak limits on the cosmological abundance
of compact objects in mass ranges from 10 to 10 . A
stronger limit is found for a much discussed universe dominated
by black holes of masses , which is ruled out at the
90% confidence level.Comment: 14 pages, 4 figures, fixed minor corrections. Accepted for
publication in ApJ(L
No Evidence for Gamma-Ray Burst/Abell Cluster or Gamma- Ray Burst/Radio-Quiet Quasar Correlations
We examine the recent claims that cosmic gamma-ray bursts are associated with
either radio-quiet quasars or Abell clusters. These associations were based on
positional coincidences between cataloged quasars or Abell clusters, and
selected events from the BATSE 3B catalog of gamma-ray bursts. We use a larger
sample of gamma-ray bursts with more accurate positions, obtained by the 3rd
Interplanetary Network, to re-evaluate these possible associations. We find no
evidence for either.Comment: Accepted for publication in the Astrophysical Journa
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