English
Related papers

Related papers: Statistical analysis of RHESSI GRB database

200 papers

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…

Astrophysics · Physics 2019-12-06 Ya. Tikhomirova , B. E. Stern

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.…

Astrophysics · Physics 2007-05-23 A. V. Kuznetsov

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…

High Energy Astrophysical Phenomena · Physics 2016-07-20 E. B. Yang , Z. B. Zhang , X. X. Jiang

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…

High Energy Astrophysical Phenomena · Physics 2017-12-25 Jakub Ripa , Arman Shafieloo

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…

Astrophysics · Physics 2009-10-31 V. I. Dokuchaev , Yu. N. Eroshenko , L. M. Ozernoy

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…

High Energy Astrophysical Phenomena · Physics 2015-06-03 S. Campana , R. Salvaterra , A. Melandri , S. D. Vergani , S. Covino , P. D'Avanzo , D. Fugazza , G. Ghisellini , B. Sbarufatti , G. Tagliaferri

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…

High Energy Astrophysical Phenomena · Physics 2011-02-21 Sandro Mereghetti

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…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Poonam Chandra , Dale A. Frail

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…

High Energy Astrophysical Phenomena · Physics 2015-06-15 LAT Collaboration

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…

High Energy Astrophysical Phenomena · Physics 2016-08-01 En-Bo Yang , Zhi-Bin Zhang , Chul-Sung Choi , Heon-Young Chang

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…

Astrophysics · Physics 2008-11-26 S. G. Bhargavi , J. Rhoads , R. Perna , J. Feldmeier , J. Greiner

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…

Cosmology and Nongalactic Astrophysics · Physics 2013-08-20 Amy Lien , Takanori Sakamoto , Neil Gehrels , David M. Palmer , Scott D. Barthelmy , Carlo Graziani , John K. Cannizzo

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…

High Energy Astrophysical Phenomena · Physics 2015-06-17 Rupal Basak , A. R. Rao

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…

Astrophysics · Physics 2009-10-28 Boris E. Stern

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.…

Astrophysics · Physics 2010-06-22 Tanuka Chattopadhyay , Ranjeev Misra , Asis Kumar Chattopadhyay , Malay Naskar

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…

Astrophysics of Galaxies · Physics 2022-10-05 B. Schneider , E. Le Floc'h , M. Arabsalmani , S. D. Vergani , J. T. Palmerio