Related papers: The polarization and beaming effect for GRBs
GRB fireballs could be ensheathed by a relativistic, baryon-enriched outflow that would in selected directions scatter a polarized beam of gamma rays. The strong polarization recently announced by RHESSI is attainable by the scattering…
Gamma Ray Bursts (GRB) observed up to redshifts $z>8$ are fascinating objects to study due to their still unexplained relativistic outburst mechanisms and a possible use to test cosmological models. Our analysis of 77 GRB afterglows with…
We report polarization measurements and photometry for the optical afterglow of the gamma-ray burst GRB 020405. We measured a highly significant 9.9% polarization (in V band) 1.3 days after the burst and argue that it is intrinsic to the…
A strong correlation is reported between gamma-ray burst (GRB) pulse lags and afterglow jet-break times for the set of bursts (seven) with known redshifts, luminosities, pulse lags, and jet-break times. This may be a valuable clue toward…
The afterglows to gamma-ray bursts (GRBs) are due to synchrotron emission from shocks generated as an ultra-relativistic outflow decelerates. A forward and a reverse shock will form, however, where emission from the forward shock is well…
Gamma-ray bursts (GRBs) were first detected thanks to their prompt emission, which was the only information available for decades. In 2010, while the high-energy prompt emission remains the main tool for the detection and the first…
The high energy neutrino emission from gamma-ray bursts (GRBs) has been expected in various scenarios. In this paper, we study the neutrino emission from early afterglows of GRBs, especially under the reverse-forward shock model and late…
The connection between Gamma-Ray Bursts (GRBs) and their afterglows is currently not well understood. Afterglow models of synchrotron emission generated by external shocks in the GRB fireball model predict emission detectable in the…
Models for gamma-ray burst afterglows envisage an hyper-relativistic fireball that is decelerated in the ambient medium around the explosion site. This interaction produces a shock wave which amplifies the magnetic field and accelerates…
Short-hard and long-soft gamma-ray bursts (GRBs) are two distinct phenomena, but their prompt and afterglow emission show many similarities. This suggests that two different progenitor systems lead to similar physical processes and that the…
The 'jet-break' in the X-ray afterglow of gamma ray bursts (GRBs) appears to be correlated to other properties of the X-ray afterglow and the prompt gamma ray emission, but the correlations are at odds with those predicted by the conical…
The shock model has successfully explained the observed behaviors of afterglows from long gamma-ray bursts (GRBs). Here we use it to investigate the so-called early afterglows from short GRBs, which arises from blast waves that are not…
We briefly discuss the theoretical implications of recent detections of gamma-ray bursts (GRBs) by BSAX. Relativistic shock wave theories of fireball expansion are challenged by the wealth of X-ray, optical and radio data obtained after the…
The prompt emission of Gamma Ray Bursts (GRBs) is still an outstanding question in the study of these cataclysmic events. Part of what makes GRBs difficult to study is how unique each event seems to be. However, aggregating many GRB…
Jet precessions are widely involved in astrophysical phenomena from galaxies to X-ray binaries and gamma-ray bursts (GRBs). Polarization presents a unique probe of the magnetic fields in GRB jets. The precession of GRBs relativistic jets…
There is growing evidence that long and hard gamma-ray bursts (GRBs), discovered at redshifts between 0.4 and 3.4, are related to some type of supernova (SN) explosions. The GRB ejecta are ultra-relativistic, and possibly beamed. There is a…
The mechanism responsible for the prompt emission of gamma-ray bursts (GRBs) is still a debated issue. The prompt phase-related GRB correlations can allow to discriminate among the most plausible theoretical models explaining this emission.…
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…
Four years after the launch the Swift satellite the nature of the Gamma Ray Bursts (GRBs) broadband afterglow behaviour is still an open issue ad the standard external shock fireball models cannot easily explain the puzzling combined…
Gamma-ray bursts (GRBs) are the most brilliant objects in the Universe but efforts to estimate the total energy released in the explosion -- a crucial physical quantity -- have been stymied by their unknown geometry: spheres or cones. We…