Related papers: A 3rd Class of Gamma Ray Bursts?
A comprehensive search of BATSE Spectroscopy Detector data from 117 GRBs has uncovered 13 statistically significant line candidates. The case of a candidate in GRB 930916 is discussed. In the data of SD 2 there appears to be a emission line…
Some articles based on the BATSE gamma-ray burst (GRB) catalog claim the existence of a third population of GRBs, besides long and short. In this contribution we wanted to verify these claims with an independent data source, namely the…
The Ginga data for the gamma-ray burst GRB870303 exhibit low-energy dips in two temporally distinct spectra, denoted S1 and S2. S1, spanning 4 s, exhibits a single line candidate at ~ 20 keV, while S2, spanning 9 s, exhibits apparently…
We explore the hypothesis, similar to one recently suggested by Bloom and colleagues, that some nearby supernovae are associated with smooth, single-pulse gamma-ray bursts, possibly having no emission above ~ 300 keV. We examine BATSE…
We summarize our model for long-duration gamma ray bursts (GRBs) that fits the redshift (z) distributions measured with Swift and missions before Swift, and the pre-Swift GRB jet opening-angle distribution inferred from achromatic breaks in…
It is known that some observed gamma-ray bursts (GRBs) are produced at cosmological distances and that the GRB production rate may follow the star formation rate. We model the BATSE-detected intensity distribution of long GRBs in order to…
Gamma-ray bursts (GRBs) come in two types, short and long. The distribution of logarithmic durations of long GRBs is asymmetric rather than Gaussian. Such an asymmetry, when modelled with a mixture of Gaussian distributions, requires an…
If gamma-ray bursters are at cosmological distances - as suggested by their isotropic distribution on the sky and by their number-intensity relation - then the burst profiles will be stretched in time, by an amount proportional to the…
We determined the characteristic variability time scales (\Delta t_p) of 410 bright and long GRBs, by locating the peaks of their Power Density Spectra, defined and calculated in the time domain. We found that the averaged variability time…
We present here our results of the temporal and spectral analysis of a sample of 52 bright and hard gamma-ray bursts (GRBs) observed with the Fermi Gamma-ray Burst Monitor (GBM) during its first year of operation (July 2008-July 2009). Our…
If \g--ray bursts are cosmological in origin, the sources are expected to trace the large--scale structure of luminous matter in the universe. I use a new likelihood method that compares the counts--in--cells distribution of \g--ray bursts…
The low energy spectra of some gamma-ray bursts' show excess components beside the power-law dependence. The consequences of such a feature allows to estimate the gamma photometric redshift of the long gamma-ray bursts in the BATSE Catalog.…
Two different luminosity indicators have recently been proposed for Gamma Ray Bursts that use gamma-ray observations alone. They relate the burst luminosity (L) with the time lag between peaks in hard and soft energies, and the spikiness or…
This article gives an overview of gamma-ray bursts (GRBs) and their relation to astroparticle physics and cosmology. GRBs are the most powerful explosions in the universe that occur roughly once per day and are characterized by flashes of…
The discovery of a number of gamma-ray bursts with duration exceeding 1,000 seconds, in particular the exceptional case of GRB 111209A with a duration of about 25,000 seconds, has opened the question on whether these bursts form a new class…
We present the discovery of two distinct classes in the Swift short duration gamma-ray bursts (S-GRBs) from the X-Ray Telescope (XRT) X-ray afterglow light curve. We find that about 40% of the Swift S-GRBs have an X-ray afterglow light…
We study timing properties of a large sample of gamma-ray bursts (GRB) detected by the Anti-Coincidence Shield (ACS) of the SPI spectrometer of INTEGRAL telescope. We identify GRB-like events in the SPI-ACS data. The data set under…
The SPI anticoincidence shield consists of 91 BGO crystals and is operated as a nearly omnidirectional gamma-ray burst detector above ~75 keV. Since the start of the mission 269 gamma-ray burst candidates have been detected. 110 bursts have…
Preliminary results of our analysis on the extended emission of short/medium duration GRBs observed with Swift/BAT are presented. The Bayesian blocks algorithm is used to analyze the burst durations and the temporal structure of the…
We study the high-energy properties of GRB 181123B, a short gamma-ray burst (sGRB) at redshift $z\approx$1.75. We show that, despite its nominal short duration with $T_{90}<$2 s, this burst displays evidence of a temporally extended…