Related papers: Observational evidence for a correlation between p…
We compare the luminosity function and rate inferred from the BATSE long bursts peak flux distribution with those inferred from the Swift peak flux distribution. We find that both the BATSE and the Swift peak fluxes can be fitted by the…
Recent optical afterglow observations of gamma-ray bursts indicate a setting and distance scale that many relate to star-formation regions. In this paper, we use $<V/V_{max}>$ and a set of artificial trigger thresholds to probe several…
Two different luminosity indicators have recently been proposed for Gamma Ray Bursts that use gamma-ray observations alone. They relate the burst luminosity (L) with the time lag between peaks in hard and soft energies, and the spikiness or…
We derive, adopting a direct method, the luminosity function and the formation rate of long Gamma Ray Bursts through a complete, flux-limited, sample of Swift bursts which has a high level of completeness in redshift z (~82%). We…
Recently proposed correlations between the energetics of Gamma-Ray Bursts (GRB) and their spectral properties, namely the peak energy of their prompt emission, are found to account for the observed fluence distribution of all `bright' BATSE…
We show that the Euclidean value of <V/Vmax> for gamma-ray bursts (GRB) selected on a timescale of 1024 ms is correlated with spectral hardness. The value of <V/Vmax> ranges from 0.42 for soft bursts to 0.26 for the hardest bursts. Given…
The $h\nu_{peak}/100 KeV \sim [E_{iso}/10^{52} \rm{erg}]^{1/2}$ correlation reported recently by Amati et al. (2002) and Lamb et al. (2003) for long GRB's can be interpreted as a viewing angle effect if the emitting region of the fireball…
The extreme luminosity of gamma-ray bursts (GRBs) and their afterglows means they are detectable, in principle, to very high redshifts. Although the redshift distribution of GRBs is difficult to determine, due to incompleteness of present…
Little is known about the diversity in the light curves of GRB-SNe, including whether the light curve of SN 1998bw can be used as a representative template or whether there is a luminosity-decline rate relation akin to that of SNe Ia. In…
Several types of extra-galactic high-energy transients have been discovered, which include high-luminosity and low-luminosity long-duration gamma-ray bursts (GRBs), short-duration GRBs, supernova shock breakouts (SBOs), and tidal disruption…
There have now been three supernova-associated gamma-ray bursts (GRBs) at redshift z < 0.17, namely 980425, 030329, and 031203, but the nearby and under-luminous GRBs 980425 and 031203 are distinctly different from the `classical' or…
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…
The energetics and emission mechanism of GRBs are not well understood. Here we demonstrate that the instantaneous peak flux or equivalent isotropic peak luminosity, L_iso ergs s^-1, rather than the integrated fluence or equivalent isotropic…
If Gamma-Ray-Bursts (GRBs) occur at high redshifts, then their bright afterglow emission can be used to probe the ionization and metal enrichment histories of the intervening intergalactic medium during the epoch of reionization. In…
Short and long-short gamma-ray bursts (GRBs) are widely believed to be powered by neutron star mergers. In this work, we calculate local rate of such GRBs and find a relatively high value of $\sim 786-2468~{\rm Gpc^{-3}~yr^{-1}}$ when…
$\gamma$-ray bursts (GRBs) are short-lived transients releasing a large amount of energy ($10^{51}-10^{53} $ erg) in the keV-MeV energy range. GRBs are thought to originate from internal dissipation of the energy carried by…
We predict the redshift distribution of Gamma-Ray Bursts (GRBs) assuming that they trace the cosmic star formation history. We find that a fraction >~50% of all GRBs on the sky originate at a redshift z >~5, even though the fraction of the…
We invert directly the redshift - luminosity distribution of observed long Swift GRBs to obtain their rate and luminosity function. Our best fit rate is described by a broken power law that rises like (1+z)^2.1{+0.5-0.6} for 0<z<3 and…
We study the effects of the beaming-induced luminosity function on statistics of observed GRBs, assuming the cosmological scenario. We select and divide the BATSE 4B data into 588 long bursts (T$_{90}>2.5$ sec) and 149 short bursts…
We compute the luminosity function (LF) and the formation rate of long gamma ray bursts (GRBs) by fitting the observed differential peak flux distribution obtained by the BATSE experiment in two different scenarios: i) the GRB luminosity…