Related papers: Gamma-ray Bursts as Distance Indicators by a Stati…
Gamma-ray bursts (GRBs) are short and intense flashes at the cosmological distances, which are the most luminous explosions in the Universe. The high luminosities of GRBs make them detectable out to the edge of the visible universe. So,…
The prompt emission mechanism of gamma-ray bursts (GRB) even after several decades remains a mystery. However, it is believed that correlations between observable GRB properties given their huge luminosity/radiated energy and redshift…
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…
Gamma-ray bursts (GRBs) are the most violent explosions in the Universe and can be used to explore the properties of high-redshift universe. It is believed that the long GRBs are associated with the deaths of massive stars. So it is…
We investigated the characteristics of the shallow decay phase in the early Xray afterglows of GRBs observed by Swift X-Ray Telescope (XRT) during the period of January 2005 to December 2006. We found that the intrinsic break time at the…
Studies of the cosmic gamma-ray bursts (GRBs) and their host galaxies are starting to provide interesting or even unique new insights in observational cosmology. GRBs represent a new way of identifying a population of star-forming galaxies…
The cosmic gamma-ray burst (GRB) formation rate, as derived from the variability-luminosity relation for long-duration GRBs, is compared with the cosmic star formation rate. If GRBs are related to the collapse of massive stars, one expects…
The Fermi Gamma-ray Burst Monitor (GBM) has detected over 1400 Gamma-Ray Bursts (GRBs) since it began science operations in July, 2008. We use a subset of over 300 GRBs localized by instruments such as Swift, the Fermi Large Area Telescope,…
Gamma-ray bursts (GRBs) are among the most luminous electromagnetic transients in the universe, providing unique insights into extreme astrophysical processes and serving as promising probes for cosmology. Unlike Type Ia supernovae, which…
Long gamma-ray bursts (GRBs) are associated with the explosion of massive stars in star forming regions. A large fraction of GRBs show intrinsic absorption as detected in optical spectra but absorption signatures are also detectable in…
Long-duration Gamma-Ray Bursts (GRBs) allow us to pinpoint and study star-forming galaxies in the early universe, thanks to their orders of magnitude brighter peak luminosities compared to other astrophysical sources, and their association…
The present common view about GRB origin is related to cosmology. There are two evidences in favour of this interpretation. The first is connected with statistics, the second is based on measurements of the redshifts in the GRB optical…
In the redshift range z = 0-1, the gamma ray burst (GRB) redshift distribution should increase rapidly because of increasing differential volume sizes and strong evolution in the star formation rate. This feature is not observed in the…
The association of long gamma-ray bursts with supernovae naturally suggests that the cosmic GRB rate should trace the star formation history. Finding otherwise would provide important clues concerning these rare, curious phenomena. Using a…
Studies of the cosmic gamma-ray bursts (GRBs) and their host galaxies are now starting to provide interesting or even unique new insights in observational cosmology. Observed GRB host galaxies have a median magnitude R ~ 25 mag, and show a…
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…
The distance scale to gamma ray bursts has been a subject of scientific debate for almost thirty years. Up to the discovery of afterglows only indirect methods could be used to constrain the distance scale to this objects. I review some of…
We collected the optical light curve data of 227 gamma-ray bursts (GRBs) observed with the TAROT, COATLI, and RATIR telescopes. These consist of 133 detections and 94 upper limits. We constructed average light curves in the observer and…
The 26 long-duration gamma-ray bursts (GRBs) with known redshifts form a distinct cosmological set, selected differently than other cosmological probes such as quasars and galaxies. Since the progenitors are now believed to be connected…
Gamma-ray bursts (GRBs) are the most luminous electromagnetic explosions in the Universe, which emit up to $8.8\times10^{54}$ erg isotropic equivalent energy in the hard X-ray band. The high luminosity makes them detectable out to the…