Related papers: Investigating the Evolution of Amati Parameters wi…
Several correlations among Gamma Ray Burst (GRB) observables with available redshifts have been recently identified. Proper evaluation and calibration of these correlations may facilitate the use of GRBs as standard candles constraining the…
(Abridged) The contemporary discoveries of galaxies and gamma ray bursts (GRBs) at high redshift have supplied the first direct information on star formation when the universe was only a few hundred million years old. The probable origin of…
We present a time-resolved spectral analysis of 51 long and 11 short bright GRBs observed with the {\em Femri}/GBM, paying special attention to $E_{\rm p}$ evolution within a same burst. Among 8 single-pulse long GRBs, 5 show hard-to-soft…
In an effort to understand the puzzle of classifying gamma-ray bursts (GRBs), we perform a systematic study of {\it Swift} GRBs and investigate several short GRB issues. Though short GRBs have a short ($\lesssim2$ s) prompt duration as…
The redshifts of the gamma ray burst (GRB) GRB 011211 has been determined as 2.14 from several absorption lines seen in the spectrum of its optical afterglow. The spectrum of its X-ray afterglow exhibited several emission lines,and their…
We present a catalog of the redshift estimates and probability distributions for 1366 individual Long-duration Gamma-Ray Bursts (LGRBs) detected by the Burst And Transient Source Experiment (BATSE). This result is based on a careful…
We present a sample of 74 Gamma-Ray Bursts (GRBs) from the Fermi-GBM catalogue for which we compute the distance moduli and use them to constrain effective dark energy models. To overcome the circularity problem affecting GRBs as distance…
Aims: We characterize a sample of Gamma-Ray Bursts with low luminosity X-ray afterglows (LLA GRBs), and study their properties. Method: We select a sample consisting of the 12\% faintest X-ray afterglows from the total population of long…
Being able to quickly select among gamma-ray bursts (GRBs) seen by the Swift satellite those which are high-z candidates would give ground-based observers a better chance to determine a redshift for such distant GRBs. Information about…
I have used a sample of long Gamma Ray Bursts (GRBs) common to both \emph{Swift} and \emph{Fermi} to re-derive the parameters of the Yonetoku correlation. This allowed me to self-consistently estimate pseudo redshifts of all the bursts with…
It is known that the soft tail of the gamma-ray bursts' spectra show excesses from the exact power-law dependence. In this article we show that this departure can be detected in the peak flux ratios of different BATSE DISCSC energy…
In this paper, we obtain two improved Amati correlations of the Gamma-Ray burst (GRB) data via a powerful statistical tool called copula. After calibrating, with the low-redshift GRB data, the improved Amati correlations based on a fiducial…
We propose a new method to use gamma-ray bursts (GRBs) as an alternative probe of the dark energy. By calibrating luminosity-variability and luminosity-lag time relations at low redshift where distance-redshift relations have been already…
After presenting a short history of gamma-ray burst (GRB) studies, we discuss the current constraints on GRB models which follows from astronomical observations. We concentrate on the energetics of the GRBs with known redshifts and the…
We study the luminosity function and formation rate of long gamma-ray bursts (GRBs) by using a maximum likelihood method. This is the first time this method is applied to a well-defined sample of GRBs that is complete in redshift. The…
We present a multi-variable regression analysis to several observable quantities for a sample of 15 gamma-ray bursts (GRBs). The observables used in the analysis includes the isotropic gamma-ray energy (E_{gamma,iso}), the peak energy of…
Gamma-Ray Bursts (GRBs) - short bursts of 100-1MeV photons arriving from random directions in the sky are probably the most relativistic objects discovered so far. Still, somehow they did not attract the attention of the relativistic…
Gamma-ray bursts (GRBs) and their afterglows have been proposed as an excellent probe to study the evolution of cosmic star formation, the reionization of the intergalactic medium, and the metal enrichment history of the universe, since the…
We use the BD2 sample of gamma-ray bursts (GRBs) based on 5.9 years of BATSE DISCLA data with a variety of models of the luminosity function to derive characteristic GRB luminosities, space densities and redshift distributions. Previously…
The high-redshift gamma-ray bursts (GRBs), GRBs 080913 and 090423, challenge the conventional GRB progenitor models by their short durations, typical for short GRBs, and their high energy releases, typical for long GRBs. Meanwhile, the GRB…