Related papers: Statistical analysis of RHESSI GRB database
Before the BATSE/GRO launch GRBs seem to be a uniform phenomenon with duration up to about 100 seconds. The BATSE has detected many events longer than 100 s and a few longer than 500s. We performed the off-line scan of the 1024 ms…
The clusters of gamma-ray bursts are considered which are assumed to be images of the repeated gamma-ray burst (GRB) sources. It is shown, that localization of the cosmic gamma-ray burst sources (GBS) is determined by the clusters of GRBs.…
Using Gaussian Mixture Model and Expectation Maximization algorithm, we have performed a density estimation in the framework of $T_{90}$ versus hardness ratio for 296 Swift/BAT GRBs with known redshift. Here, Bayesian Information Criterion…
The sky distribution of Gamma-Ray Bursts (GRBs) has been intensively studied by various groups for more than two decades. Most of these studies test the isotropy of GRBs based on their sky number density distribution. In this work we…
Recently we have elaborated a new cosmological model of gamma-ray burst (GRB) origin (1998, ApJ 502, 192), which employs the dynamical evolution of central dense stellar clusters in the galactic nuclei. Those clusters inevitably contain a…
A complete sample of bright Swift Gamma-ray Bursts (GRBs) has been recently selected by Salvaterra et al. (2011). The sample has a high level of completeness in redshift (91%). We derive here the intrinsic absorbing X-ray column densities…
Despite not being specifically designed for the study of gamma-ray bursts (GRBs), the INTEGRAL satellite is giving a relevant contribution to this field with the detection of about 10 GRB per year in the IBIS field of view. The ground-based…
We present a catalog of radio afterglow observations of gamma-ray bursts (GRBs) over a 14 year period from 1997 to 2011. Our sample of 304 afterglows consists of 2995 flux density measurements (including upper limits) at frequencies between…
Gamma Ray Bursts (GRBs) bridge relativistic astrophysics and multi-messenger astronomy. Space-based gamma/X-ray wide field detectors have proven essential to detect and localize the highly variable GRB prompt emission, which is also a…
In three years of observations since the beginning of nominal science operations in August 2008, the Large Area Telescope (LAT) on board the Fermi Gamma Ray Space Telescope has observed high-energy (>20 MeV) \gamma-ray emission from 35…
Gamma Ray Bursts (GRBs) are a powerful probe of the high redshift Universe. We present a tool to estimate the detection rate of high-z GRBs by a generic detector with defined energy band and sensitivity. We base this on a population model…
Using Gaussian Mixture Model (GMM) and Expectation Maximization Algorithm, we perform an analysis of time duration ($T_{90}$) for \textit{CGRO}/BATSE, \textit{Swift}/BAT and \textit{Fermi}/GBM Gamma-Ray Bursts. The $T_{90}$ distributions of…
Gamma Ray Bursts (GRBs) are expected to leave behind GRB remnants, similar to how ``standard'' supernovae (SN) leave behind SN remnants. The identification of these remnants in our own and in nearby galaxies would allow a much closer look…
The long gamma-ray burst (GRB) rate is essential for revealing the connection between GRBs, supernovae and stellar evolution. Additionally, the GRB rate at high redshift provides a strong probe of star formation history in the early…
It has been proposed that coherent radio emission could be emitted during or shortly following a gamma-ray burst (GRB). Here we present a low-frequency ($170-200$ MHz) search for radio pulses associated with long-duration GRBs using the…
We make a detailed pulse-wise study of gamma-ray bursts (GRBs) with known redshift detected by \emph{Fermi}/Gamma Ray Burst Monitor (GBM). The sample contains 19 GRBs with 43 pulses. We find that the average peak energy is correlated to the…
Individual gamma ray bursts (GRBs) have very diverse time behavior - from a single pulse to a long complex sequence of chaotic pulses of different timescales. I studied light curves of GRBs using data from the CGRO's BATSE experiment and…
Two different multivariate clustering techniques, the K-means partitioning method and the Dirichlet process of mixture modeling, have been applied to the BATSE Gamma-ray burst (GRB) catalog, to obtain the optimum number of coherent groups.…
We present results from the first two years of our fast-cadence 15 GHz gamma-ray blazar monitoring program, part of the F-GAMMA radio monitoring project. Our sample includes the 1158 blazars north of -20 degrees declination from the…
(Abridged) Long Gamma-Ray Bursts (GRBs) offer a promising tool to trace the cosmic history of star formation, especially at high redshift where conventional methods are known to suffer from intrinsic biases. Previous studies of GRB host…