Related papers: Failed optical afterglows
We examine a sample of 21 gamma-ray burst (GRB) afterglow light curves at radio frequencies, and compare them to the X-ray and/or optical properties of the afterglows and to the predictions of the standard jet/fireball model. Our sample…
(Abridged) Until recently the information inferred from gamma-ray burst follow-up observations was mostly limited to optically bright afterglows, biasing all demographic studies against sight-lines that contain large amounts of dust. Here,…
We have examined the complete set of X-ray afterglow observations of dark and optically bright GRBs performed by BeppoSAX until February 2001. X-ray afterglows are detected in 90% of the cases. We do not find significant differences in the…
We present the X-ray afterglow catalog of BeppoSAX from the launch of the satellite to the end of the mission. Thirty-three X-ray afterglows were securely identified based on their fading behavior out of 39 observations. We have extracted…
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…
If gamma ray bursts are highly collimated, radiating into only a small fraction of the sky, the energy requirements of each event may be reduced by several (up to 4 - 6) orders of magnitude, and the event rate increased correspondingly. The…
Gamma Ray Burst (GRB) afterglows close to their peak intensity are among the brightest X-ray sources in the sky. Despite their fast power-law like decay, when fluxes are integrated from minutes up to hours after the GRB event, the…
With the early afterglow localizations of gamma-ray burst positions made by Swift, the clear delimitation of the prompt phase and the afterglow is not so obvious any more. It is important to see weather the two phases have the same origin…
We calculate the expected spectrum and light curves of the early afterglow. For short GRBs the peak of the afterglow will be delayed, typically, by a few dozens of seconds after the burst. The x-ray and gamma-ray characteristics of this…
Microlensing of a gamma-ray burst afterglow by an intervening star can be used to infer the radial structure of the afterglow image. Near the peak of the microlensing event, the outer edge of the image is more highly magnified than its…
We present ground-based optical observations of GRB 020124 starting 1.6 hours after the burst, as well as subsequent Very Large Array (VLA) and Hubble Space Telescope (HST) observations. The optical afterglow of GRB 020124 is one of the…
We present an update of our systematic analysis of all Gamma-Ray Burst (GRB) afterglow data, now published through the end of 2004, in an attempt to detect the predicted supernova light component. We fit the observed photometric light…
In this paper we present a sample of 10 short gamma-ray bursts (GRBs) with a robust redshift determination, discovered by the Swift satellite up to January 2011. We measure their X-ray absorbing column densities and collect data on the host…
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…
We study the properties of the population of optically dark events present in a carefully selected complete sample of bright Swift long gamma-ray bursts. The high level of completeness in redshift of our sample (52 objects out of 58) allow…
We analyze a complete sample of gamma-ray burst afterglows, and find X-ray evidence for high column densities of gas around them. The column densities are in the range 1e+22-1e+23/cm2, which is right around the average column density of…
Starting as highly relativistic collimated jets, gamma-ray burst outflows gradually decelerate and become non-relativistic spherical blast waves. Although detailed analytical solutions describing the afterglow emission received by an…
Since gamma-ray burst afterglows were first detected in 1997, the relativistic fireball model has emerged as the leading theoretical explanation of the afterglows. In this paper, we present a very general, Bayesian inference formalism with…
Well-sampled optical lightcurves of 146 gamma-ray bursts (GRBs) are complied from the literature. Multiple optical emission components are extracted with power-law function fits to these lightcurves. We present a systematical analysis for…
Optical and radio afterglows arising from the shocks by relativistic conical ejecta running into pre-burst massive stellar winds are revisited. Under the homogeneous thin-shell approximation and a realistic treatment for the lateral…