Related papers: Testing for Extragalactic Correlations of Gamma-Ra…
Progenitor stars of long gamma-ray bursts (GRBs) could be surrounded by a significant and complex nebula structure lying at a parsec scale distance. After the initial release of energy from the GRB jet, the jet will interact with this…
We collected the information of 304 gamma-ray bursts (GRBs) from the literature, and analyzed the correlations among the host galaxy offsets (the distance from the site of the GRB to the center of its host galaxy), $T_{\rm 90,i}$ (the…
Observations of GRB host galaxies and their environments in general can provide valuable clues about the nature of progenitors. Bursts are associated with faint, <R> ~ 25 mag, galaxies at cosmological redshifts, <z> ~ 1. The host galaxies…
The host galaxies of nearby (z<0.3) core-collapse supernovae and long-duration gamma-ray bursts offer an excellent means of probing the environments and populations that produce these events' varied massive progenitors. These same young…
Long duration gamma-ray bursts (GRBs) accompany the deaths of some massive stars and hence, since massive stars are short lived, are a tracer of star formation activity. Given that GRBs are bright enough to be seen to very high redshifts,…
Gamma-Ray Bursts (GRBs) fall into two classes: short-hard and long-soft bursts. The latter are now known to have X-ray and optical afterglows, to occur at cosmological distances in star-forming galaxies, and to be associated with the…
The detection of supernova features in the late spectra of several gamma-ray burst afterglows has shown that at least a fraction of long-duration gamma-ray bursts are associated to the final evolutionary stages of massive stars. Such direct…
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 study the nature of long gamma ray burst (LGRB) progenitors using cosmological simulations of structure formation and galactic evolution. LGRBs are potentially excellent tracers of stellar evolution in the early universe. We developed a…
Gamma-ray bursts (GRBs) are the most luminous explosions and can be detectable out to the edge of Universe. It has long been thought they can extend the Hubble diagram to very high redshifts. Several correlations between temporal or…
We study a cosmological scenario for gamma ray bursts (GRBs) where relativistic flows interact with dense radiation fields. It is shown that this scenario is plausible in very dense stellar regions which are known to exist in collapsed…
A significant fraction (30\%) of well-localized short gamma-ray bursts (sGRBs) lack a coincident host galaxy. This leads to two main scenarios: \textit{i}) that the progenitor system merged outside of the visible light of its host, or…
We used 45 orbits of Hubble Space Telescope time in Cycle 9 to obtain deep STIS/CCD images of the host galaxies of eleven gamma-ray bursts. Our goals are to study the morphologies of the host galaxies, to obtain precise locations of…
The surest solution of the Gamma Ray Burst (GRB) mystery is to find an unambiguous low-energy quiescent counterpart. However, to date no reasonable candidates have been identified in the x-ray, optical, infrared, or radio ranges. The Hubble…
Nearby gamma-ray bursts (GRBs) are likely to have represented a significant threat to life on the Earth. Recent observations suggest that a significant source of such bursts is compact binary mergers in globular clusters. This link between…
Gamma-ray bursts (GRBs) are luminous enough to be detectable up to redshift $z\sim 10$. They are often proposed as complementary tools to type-Ia supernovae (SNe Ia) in tracing the Hubble diagram of the Universe. The distance calibrations…
We have tested several models of GRB luminosity and redshift distribution functions for compatibility with the BATSE 4B number versus peak flux relation. Our results disagree with recent claims that current GRB observations can be used to…
The frequency of short gamma-ray bursts (GRBs) in galaxies with distinct star formation histories can be used to constrain the lifetime of the progenitor systems. As an illustration, we consider here the constraints that can be derived from…
Gamma-Ray Bursts (GRBs) are extra-galactic and extremely energetic transient emissions of gamma rays, which are thought to be associated with the death of massive stars or the merger of compact objects in binary systems. Their huge…
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…