Related papers: Classification of Gamma-Ray Burst durations using …
Gamma-ray bursts (GRBs) are classified as Type I GRBs originated from compact binary mergers and Type II GRBs originated from massive collapsars. While Type I GRBs are typically shorter than 2 seconds, recent observations suggest that some…
We study correlations between various hardness ratios of gamma-ray bursts (GRBs) and investigate if there are any differences between the two classes of the objects in the distributions of the ratios. The results suggest that,…
We have investigated the bimodal distribution of the duration of BATSE gamma-ray bursts (GRBs) by analyzing light curves of 64 ms time resolution. We define the average pulse width of GRBs from the auto-correlation function of GRB profiles.…
We compute the probability to detect long Gamma Ray Bursts (GRBs) at z>5 with Swift, assuming that GRBs form preferentially in low-metallicity environments. The model fits well both the observed BATSE and Swift GRB differential peak flux…
We find that dim gamma-ray bursts (GRBs) are softer than bright GRBs, as indicated on average by data from the Burst and Transient Source Experiment (BATSE) on board the Compton Gamma Ray Observatory. We show that this correlation is…
It was recently shown that the $T_{90}-H_{32}$ distributions of gamma-ray bursts from CGRO/BATSE and Fermi/GBM are well described by a mixture of only two skewed components, making the presumed third, intermediate class unnecesary. The…
We compare the spectral properties of 79 short and 79 long Gamma-Ray Bursts (GRBs) detected by BATSE and selected with the same limiting peak flux. Short GRBs have a low-energy spectral component harder and a peak energy slightly higher…
The intermediate-duration gamma-ray bursts (GRBs) identified in the data of the RHESSI satellite are investigated with respect to their spectral lags, peak count rates, redshifts, supernova observations, and star formation rates of their…
Some short GRBs are followed by longer extended emission, lasting anywhere from ~10 to ~100 s. These short GRBs with extended emission (EE) can possess observational characteristics of both short and long GRBs (as represented by GRB…
Gamma-ray bursts (GRBs) can be probes of the early universe, but currently, only 26% of GRBs observed by the Neil Gehrels Swift Observatory GRBs have known redshifts ($z$) due to observational limitations. To address this, we estimated the…
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…
Kouveliotou et al. (1993) recently confirmed that gamma-ray bursts are bimodal in duration. In this paper we compute the statistical properties of the short ($\le 2$~s) and long ($>2$~s) bursts using a method of analysis that makes no…
The modified version of a bullet model for gamma ray bursts is studied. The central engine of the source produces multiple sub-jets that are contained within a cone. The emission of photons in the source frame of a sub-jet either takes part…
We study the distribution of the durations of gamma-ray bursts (GRBs) in the unified model of short and long GRBs recently proposed by Yamazaki, Ioka, and Nakamura. Monte Carlo simulations show clear bimodal distributions, with…
A sample of 427 gamma-ray bursts (GRBs), measured by the RHESSI satellite, is studied statistically with respect to duration and hardness ratio. Standard statistical tests are used, such as $\chi^2$, F-test and the maximum likelihood ratio…
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 traditionally classified into long (lGRBs) and short (sGRBs) durations based on their $T_{90}$, with lGRBs widely used as tracers of the cosmic star formation rate (SFR) due to their observed association with…
We compare the properties of optically dark GRBs, defined by the optical-to-X-ray spectral index beta_OX<0.5, and normal ones discovered by the Swift satellite before the year 2008 in a statistical way, using data collected from the…
The empirical classification of Gamma-Ray Bursts (GRBs) is based on their distribution in the plane of burst duration and spectral hardness. Two distinct distributions, long-soft and short-hard bursts, are observed in this plane, forming…
Gamma-ray bursts (GRBs) are generally categorized into long and short bursts based on their duration ($T_{90}$). Recently, it has been proposed that GRBs can also be classified into type I (merger) and type II (collapsar) bursts based on…