Related papers: GRB 210217A: A short or a long GRB?
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 present an analysis of early BAT and XRT data for 107 gamma--ray bursts (GRBs) observed by the Swift satellite. We use these data to examine the behaviour of the X-ray light curve and propose a classification scheme for GRBs based on…
Gamma-ray bursts (GRBs) are a mixed class of sources consisting of, at least, the long duration and short-hard subclasses, the X-ray flashes, and the low-luminosity GRBs. In all cases, the release of enormous amounts of energy on a short…
Gamma-ray bursts (GRBs) offer a powerful window to probe the progenitor systems responsible for the formation of heavy elements through the rapid neutron capture (r-) process, thanks to their exceptional luminosity, which allows them to be…
On March 7th, 2023 the \textit{Fermi} Gamma-ray Burst Monitor observed the second highest fluence gamma-ray burst (GRB) ever, GRB~230307A. With a duration beyond 100~s, GRB~230307A contains a multitude of rapidly-varying peaks, and was so…
Gamma-ray bursts are usually classified through their high-energy emission into short-duration and long-duration bursts, which presumably reflect two different types of progenitors. However, it has been shown on statistical grounds that a…
The recent association of several short gamma-ray bursts (GRBs) with early type galaxies with low star formation rate demonstrates that short bursts arise from a different progenitor mechanism than long bursts. However, since the duration…
We consider whether the variability properties of Gamma-Ray Bursts (GRBs) that produce bright optical and longer wavelength transient afterglows (A-GRBs) are the same as a larger, inclusive sample of bright, long-duration GRBs, selected…
Two classes of Gamma Ray Bursts have been identified so far, characterized by T90 durations shorter and longer than approximately 2 seconds. It was shown that the BATSE 3B data allow a good fit with three Gaussian distributions in log T90.…
We compare the prompt intrinsic spectral properties of a sample of short Gamma--ray Burst (GRB) with the first 0.3 seconds (rest frame) of long GRBs observed by Fermi/GBM. We find that short GRBs and the first part of long GRBs lie on the…
In the present paper, we investigated the distribution of hardness ratio (HR) for short and long gamma-ray bursts (GRBs) in different time scales for the first two seconds. After including and subtracting the background count, we performed…
Phenomenologically, two classes of GRBs (long/soft vs. short/hard) are identified based on their gamma-ray properties. The boundary between the two classes is vague. Multi-wavelength observations lead to identification of two types of GRB…
We study the properties of short gamma-ray bursts (GRBs), based on the assumption that they are all connected to the binary neutron star mergers, whose formation mechanism contains a large amount of uncertainty. In particular, the merger…
Two classes of gamma-ray bursts have been identified in the BATSE catalogs characterized by durations shorter and longer than about 2 seconds. There are, however, some indications for the existence of a third class. Swift satellite…
We propose a possible unified model of short and long gamma-ray bursts (GRBs), X-ray rich GRBs, and X-ray flashes. The jet of a GRB is assumed to consist of multiple sub-jets or sub-shells (i.e., an inhomogeneous jet model). The…
Gamma-ray bursts (GRBs) are the universe's most energetic phenomena (isotropic luminosity $\sim 10^{51} - 10^{54}$ ergs/s) lasting for a very short duration ($\sim$ milliseconds - a few seconds). Even after an average of one GRB detected…
Classification of gamma-ray bursts (GRBs) into groups has been intensively studied by various statistical tests in previous years. It has been suggested that there was a distinct group of GRBs, beyond the long and short ones, with…
In light of the joint multimessenger detection of a binary neutron star merger as the gamma-ray burst GRB 170817A and in gravitational waves as GW170817, we reanalyze the Fermi Gamma-ray Burst Monitor data of one of the closest short…
Context. Gamma-ray bursts (GRBs) have traditionally been classified by duration into long (LGRBs) and short (SGRBs), with the former believed to originate from massive star collapses and the latter from compact binary mergers. However,…
If the efficiency for producing $\gamma$-rays is the same in short duration ($\siml 2$ s) Gamma-Ray Bursts (GRBs) as in long duration GRBs, then the average kinetic energy of short GRBs must be $\sim 20$ times less than that of long GRBs.…