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We study the evolution with redshift of three measures of gamma-ray burst (GRB) duration ($T_{\rm 90}$, $T_{\rm 50}$ and $T_{\rm R45}$) in a fixed rest frame energy band for a sample of 232 Swift/BAT detected GRBs. Binning the data in…

High Energy Astrophysical Phenomena · Physics 2015-06-22 O. M. Littlejohns , N. R. Butler

Two tests for cosmological time dilation in $\gamma$-ray bursts -- the peak alignment and auto-correlation statistics -- involve averaging information near the times of peak intensity. Both tests require width corrections, assuming…

Astrophysics · Physics 2009-10-28 J. P. Norris , R. J. Nemiroff , J. T. Bonnell , J. D. Scargle

Gamma-ray bursts (GRBs) are detectable out to very large distances and as such are potentially powerful cosmological probes. Historically, the angular distribution of GRBs provided important information about their origin and physical…

High Energy Astrophysical Phenomena · Physics 2015-11-11 T. N. Ukwatta , P. R. Wozniak

We use a new method of analysis to determine parameters of cosmological gamma-ray bursts (GRBs), assuming that their distribution follows the star-formation history of the universe. Spectral evolution is calculated from an external shock…

Astrophysics · Physics 2015-06-24 M. Boettcher , C. D. Dermer

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…

The isotropic distribution of gamma-ray bursts as observed with the Burst and Transient Experiment (BATSE) strongly suggests that the bursts are at cosmological distances. At such distances, the expansion of the universe should redshift the…

Astrophysics · Physics 2009-10-28 Ed E. Fenimore , Joshua S. Bloom

We present analytic formulae for the integral number count distribution of cosmological bursting or steady sources valid over the entire range of fluxes, including density evolution and either standard candle or a power law luminosity…

Astrophysics · Physics 2009-10-28 A. Meszaros , P. Meszaros

We show how the redshift and peak-flux distributions of gamma-ray bursts (GRBs) have an observation time dependence that can be used to discriminate between different burst populations. We demonstrate how observation time relations can be…

High Energy Astrophysical Phenomena · Physics 2013-02-20 E. J. Howell , D. M. Coward

Two classes of gamma-ray bursts were identified in the BATSE catalogs characterized by their durations. There were also some indications for the existence of a third type of gamma-ray bursts. Swift satellite detectors have different…

High Energy Astrophysical Phenomena · Physics 2009-12-21 I. Horvath , Z. Bagoly , L. G. Balazs , G. Tusnady , P. Veres

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…

One of the most important task of the Gamma-Ray Burst field is the classification of the bursts. Many researches have proven the existence of the third kind (intermediate duration) of GRBs in the BATSE data. Recent works have analyzed…

High Energy Astrophysical Phenomena · Physics 2015-04-30 I. Horvath , Z. Bagoly , A. de Ugarte Postigo , L. G. Balazs , P. Veres

We show that the time variability of a gamma-ray burst (GRB) appears to be correlated with the absolute luminosity of the burst: smooth bursts are intrinsically less luminous. This Cepheid-like relationship can be used to determine the…

Astrophysics · Physics 2007-05-23 E. E. Fenimore , E. Ramirez-Ruiz

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 one. Swift satellite detectors…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 István Horváth , Lajos G. Balázs , Péter Veres

The redshift distribution of gamma-ray bursts collected in the BATSE Catalog is compared with the star formation rate. We aim to clarify the accordance between them. We also study the case of comoving number density of bursts monotonously…

Astrophysics · Physics 2009-11-11 A. Meszaros , Z. Bagoly , L. G. Balazs , I. Horvath

We propose a redshift estimator for the long ($T_{90} > 20$) gamma-ray bursts (GRBs) observed by the BATSE. It is based on an empirical relation between the redshift and the power-law index of power density spectra (PDSs) of the observed…

Astrophysics · Physics 2007-05-23 Heon-Young Chang , Suk-Jin Yoon , Chul-Sung Choi

In order to explain the origin of skewness in the gamma-ray burst (GRB) duration distribution, a statistical model, based on the cosmological time dilation and taking into account the GRB formation rate and instrumental effects, is…

High Energy Astrophysical Phenomena · Physics 2020-07-15 Mariusz Tarnopolski

We predict the redshift distribution of long Gamma-Ray Bursts (GRBs) with Monte Carlo simulations. Our improved analysis constrains free parameters with three kinds of observation: (i) the log(N)-log(P) diagram of BATSE bursts; (ii) the…

Astrophysics · Physics 2008-11-26 F. Daigne , E. M. Rossi , R. Mochkovitch

Studies of \textit{BATSE} bursts \citep{kouveliotou:93} have resulted in the widespread adoption of a two-group categorization: long bursts (those with durations $\geq 2$ seconds) and short bursts (those with durations $\leq 2$ seconds).…

High Energy Astrophysical Phenomena · Physics 2016-11-29 Hannachi Zitouni , Nidhal Guessoum , Walid Jamil Azzam , Robert Mochkovitch

We compare the burst distribution of the new (2B) BATSE catalogue to a cosmological distribution. The observed distribution agrees well with a cosmological one, however, it is insensitive to cosmological parameters such as $\O$ and…

Astrophysics · Physics 2009-10-28 Ehud Cohen , Tsvi Piran

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
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