4,973 research outputs found
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
The Ulysses Supplement to the BATSE 4Br Catalog of Cosmic Gamma-Ray Bursts
We present Interplanetary Network localization information for 147 gamma-ray
bursts observed by the Burst and Transient Source Experiment between the end of
the 3rd BATSE catalog and the end of the 4th 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 2.3 degrees, 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 25.Comment: Accepted for publication in the Astrophysical Journal Supplemen
SGR 1806-20 Is a Set of Independent Relaxation Systems
The Soft Gamma Repeater 1806-20 produced patterns of bursts during its 1983
outburst that indicate multiple independent energy accumulation sites, each
driven by a continuous power source, with sudden, incomplete releases of the
accumulated energy. The strengths of the power sources and their durations of
activity vary over several orders of magnitude.Comment: Accepted ApJLett, 15 pages, 3 figure
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
The Interplanetary Network Supplement to the BeppoSAX Gamma-Ray Burst Catalogs
Between 1996 July and 2002 April, one or more spacecraft of the
interplanetary network detected 787 cosmic gamma-ray bursts that were also
detected by the Gamma-Ray Burst Monitor and/or Wide-Field X-Ray Camera
experiments aboard the BeppoSAX spacecraft. During this period, the network
consisted of up to six spacecraft, and using triangulation, the localizations
of 475 bursts were obtained. We present the localization data for these events.Comment: 89 pages, 3 figures. Submitted to the Astrophysical Journal
Supplement Serie
Nature of fault planes in solid neutron star matter
The properties of tectonic earthquake sources are compared with those deduced
here for fault planes in solid neutron-star matter. The conclusion that
neutron-star matter cannot exhibit brittle fracture at any temperature or
magnetic field is significant for current theories of pulsar glitches, and of
the anomalous X-ray pulsars and soft-gamma repeaters.Comment: 5 AAS LaTeX pages 1 eps figur
The distances of short-hard GRBs and the SGR connection
We present a search for nearby (D<100 Mpc) galaxies in the error boxes of six
well-localized short-hard gamma-ray bursts (GRBs). None of the six error boxes
reveals the presence of a plausible nearby host galaxy. This allows us to set
lower limits on the distances and, hence, the isotropic-equivalent energy of
these GRBs. Our lower limits are around erg (at
confidence level); as a consequence, some of the short-hard GRBs we examine
would have been detected by BATSE out to distances greater than 1 Gpc and
therefore constitute a bona fide cosmological population. Our search is
partially motivated by the December 27, 2004 hypergiant flare from SGR 1806-20,
and the intriguing possibility that short-hard GRBs are extragalactic events of
a similar nature. Such events would be detectable with BATSE to a distance of
\~50 Mpc, and their detection rate should be comparable to the actual BATSE
detection rate of short-hard GRBs. The failure of our search, by contrast,
suggests that such flares constitute less than 15% of the short-hard GRBs (<40%
at 95% confidence). We discuss possible resolutions of this discrepancy.Comment: Enlarged sample of bursts; ApJ in pres
Are Abell Clusters Correlated with Gamma-Ray Bursts?
A recent study has presented marginal statistical evidence that gamma-ray
burst sources are correlated with Abell clusters, based on analyses of bursts
in the BATSE 3B catalog. Using precise localization information from the 3rd
Interplanetary Network, we have reanalyzed this possible correlation. We find
that most of the Abell clusters which are in the relatively large 3B error
circles are not in the much smaller IPN/BATSE error regions. We believe that
this argues strongly against an Abell cluster-gamma-ray burst correlation.Comment: accepted for publication in Astrophysical Journal Letter
Lognormal Properties of SGR 1806-20 and Implications for Other SGR Sources
The time interval between successive bursts from SGR 1806-20 and the
intensity of these bursts are both consistent with lognormal distributions.
Monte Carlo simulations of lognormal burst models with a range of distribution
parameters have been investigated. The main conclusions are that while most
sources like SGR 1806-20 should be detected in a time interval of 25 years,
sources with means about 100 times longer have a probability of about 5\% of
being detected in the same interval. A new breed of experiments that operate
for long periods are required to search for sources with mean recurrence
intervals much longer than SGR 1806-20.Comment: 4 pages, latex with seperate file containing 2 uuencoded, gzip'ed,
tarred, .eps figures. Replaced with file that does not use kluwer.sty to
allow automatic postscript generation. To appear in proceedings of ESLAB 2
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