Related papers: Stellar Sources of Gamma-Bursts
We report evidence from the 3B Catalogue that long ($T_{90} > 10$ s) and short ($T_{90} < 10$ s) gamma-ray bursts represent distinct source populations. Their spatial distributions are significantly different, with long bursts having…
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…
The nearby long GRB 060614 was not accompanied by a supernova, challenging the collapsar model for long-duration GRBs and the traditional classification scheme for GRBs. However, Cobb et al. have argued that the association of GRB 060614…
The spatial distribution of short Gamma-ray bursts (GRBs) in their host galaxies provide us an opportunity to investigate their origins. Based on the currently observed distribution of short GRBs relative to their host galaxies, we obtain…
Gamma-ray bursts are the most luminous explosions in the Universe, whose origin and mechanism is the focus of intense interest. They appear connected to supernova remnants from massive stars or the merger of their remnants, and their…
The nearby, 30 to 40 Myr old, starburst region of the Gould Belt has formed numerous massive stars. Within its 300 pc radius, it produces core-collapse supernovae at an enhanced rate which is shown to be 75 to 95 Myr{-1} kpc{-2}, i.e. 3 to…
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 class. Swift satellite…
The spatial distribution of sources of gamma-ray bursts (GRB) with known red shifts is analyzed by the conditional density and pairwise distance methods. The sample of GRB is based on data from the Swift mission and contains fluxes,…
Gamma-ray bursts (GRBs) are short and most intense bursts of gamma-rays that come from random direction in space. Their origin are still unknown and they originate likely from cosmological distances, probably after birth of a new black hole…
Cosmic gamma-ray bursts are one of the great frontiers of astrophysics today. They are a playground of relativists and observers alike. They may teach us about the death of stars and the birth of black holes, the physics in extreme…
$\gamma$-ray bursts have baffled theorists ever since their accidental discovery at the sixties. We suggest that these bursts originate in merger of neutron star binaries, taking place at cosmological distances. These mergers release…
We investigate the possibility that gamma-ray bursts originate in a concentric spherical shell with a given average redshift and find that this is indeed compatible with the data from the third BATSE (3B) catalog. It is also shown that…
Gamma-ray bursts (GRBs) are extremely energetic events at cosmological distances. They provide unique laboratory to investigate fundamental physical processes under extreme conditions. Due to extreme luminosities, GRBs are detectable at…
The currently accepted model for gamma-ray burst phenomena involves the violent formation of a rapidly rotating solar mass black hole. Gravitational waves should be associated with the black-hole formation, and their detection would permit…
Gamma ray burst sources are isotropically distributed. They could be located at distances $\sim 1000$ AU. (Katz \cite{JK92}) GRB signals have many narrow peaks that are unresolved at the millisecond time resolution of existing observations.…
Relativistic flows resulting from sudden explosive events upscatter ambient interstellar photons of local radiation fields. For Lorentz factor $ > 100$ and dense optical - UV radiation fields the emergent signal is a typical gamma ray…
Gamma ray bursts (GRBs) are known to come in two duration classes, separated at ~2 s. Long bursts originate from star forming regions in galaxies, have accompanying supernovae (SNe) when near enough to observe and are likely caused by…
Starburst galaxies exhibit in their central regions a highly increased rate of supernovae, the remnants of which are thought to accelerate energetic cosmic rays up to energies of ~ 10^15 eV. We report the detection of gamma rays -- tracers…
We cross correlate Gamma--Ray Bursts and X--Ray selected clusters of galaxies at z\leq0.45. We find a positive 2\sigma signal for the angular cross--correlation function w_{bc}(\theta) on scales \theta\leq 3 deg between short GRBs and…
We statistically study gamma-ray burst (GRB) optical flares from the Swift/UVOT catalog. We compile 119 optical flares, including 77 flares with redshift measurements. Some tight correlations among the time scales of optical flares are…