Related papers: Energetics and Luminosity Function of Gamma-ray Bu…
If Gamma-Ray Bursts (GRBs) are cosmologically distributed standard candles and are associated with the luminous galaxies, then the observed angular distribution of all GRBs is altered due to weak gravitational lensing of bursts by density…
Forward shocks caused by the interaction between a relativistic blast wave and the circum-burst medium are thought to be responsible for the afterglow emission in Gamma-Ray Bursts (GRBs). We consider the hydrodynamics of a spherical…
The observations of gamma-ray bursts (GRBs) such as 980425, 031203 and 060218, with luminosities much lower than those of other classic bursts, lead to the definition of a new class of GRBs -- low-luminosity GRBs. The nature of the outflow…
Correlation studies of prompt and afterglow emissions from gamma-ray bursts (GRBs) between different spectral bands has been difficult to do in the past because few bursts had comprehensive and intercomparable afterglow measurements. In…
The variability observed in many complex gamma-ray bursts (GRBs) is inconsistent with causally connected variations in a single, symmetric, relativistic shell interacting with the ambient material ("external shocks"). Rather, the symmetry…
In order to constrain the broad-band spectral energy distribution of the afterglow of GRB 100621A, dedicated observations were performed in the optical/near-infrared with the 7-channel "Gamma-Ray Burst Optical and Near-infrared Detector"…
We argue that recent observations of afterglows and some theoretical considerations indicate that the gamma-ray fluence may be a better measure of strength of a burst than its peak flux. We discuss how the distribution of the fluence, or…
Assuming an adiabatic evolution of a Gamma-Ray Burst (GRB) remnant interacting with an external medium, we calculate the injection, cooling, and absorption break frequencies, and the afterglow flux for plausible orderings of the break and…
Major advances have been made in the field of gamma-ray bursts in the last two years. The successful discovery of X-ray, optical and radio afterglows, which were predicted by theory, has made possible the identification of host galaxies at…
Gamma-ray bursts (GRB) are sudden, intense flashes of gamma-rays which, for a few blinding seconds, light up in an otherwise fairly dark gamma-ray sky. They are detected at the rate of about once a day, and while they are on, they outshine…
The origin of gamma-ray bursts (GRBs) has been enigmatic since their discovery. The situation improved dramatically in 1997, when the rapid availability of precise coordinates for the bursts allowed the detection of faint optical and radio…
Gamma-ray bursts with long durations are widely thought to arise from the collapse of massive stars, where the wind environment is unavoidable. It is also believed that $\gamma$-ray bursts come from jets. Considering these two points in…
The afterglow emission has become the main stream of Gamma-Ray burst research since its discovery three years ago. With the distance-scale enigma solved, the study of the late-time GRB emission is now the most promising approach to disclose…
We predict the rate at which Gamma-Ray Burst (GRB) afterglows should be detected in supernova searches as a function of limiting flux. Although GRB afterglows are rarer than supernovae, they are detectable at greater distances because of…
Evidence suggests that the gamma-ray burst (GRB) ejecta is likely magnetized, although the degree of magnetization of the ejecta is unknown. We derive a rigorous analytical solution for the relativistic 90 degree shocks under the ideal MHD…
We present an updated catalog of 113 X-ray flares detected by Swift in the ~33% of the X-ray afterglows of Gamma-Ray Bursts (GRB). 43 flares have a measured redshift. For the first time the analysis is performed in 4 different X-ray energy…
The unrivalled, extreme luminosities of gamma-ray bursts (GRBs) make them the favored beacons for sampling the high redshift Universe. To employ GRBs to study the cosmic terrain -- e.g., star and galaxy formation history -- GRB luminosities…
Observations of individual bursts chosen by the vagaries of telescope availability demonstrated that bursts are not standard candles and that their apparent energy can be as great as 10^54 erg. However, determining the distribution of their…
The energy requirements of gamma ray bursts have in past been poorly constrained because of three major uncertainties: The distances to bursts, the degree of burst beaming, and the efficiency of gamma ray production. The first of these has…
The Gamma-Ray burst (GRB) - afterglow transition is one of the most interesting and least studied GRB phases. During this phase the relativistic ejecta begins interacting with the surrounding matter. A strong short lived reverse shock…