Related papers: Energy Injection in GRB Afterglow Models
We present and discuss the results of an extensive observational campaign devoted to GRB071010A, a long-duration gamma-ray burst detected by the Swift satellite. This event was followed for almost a month in the optical/near-infrared (NIR)…
Many previous studies have determined that the long lasting emission at X-ray, optical and radio wavelengths from gamma-ray bursts (GRBs), called the afterglow, is likely produced by the external forward shock model. In this model, the GRB…
Observations of gamma ray bursts (GRB) afterglows in different spectral bands provide a most valuable information about their nature, as well as about properties of surrounding medium. Powerful infrared afterglow was observed from the…
We report a multi-wavelength analysis of the prompt emission and early afterglow of GRB051111 and discuss its properties in the context of current fireball models. The detection of GRB051111 by the Burst Alert Telescope on-board Swift…
We present a detailed broadband afterglow study of GRB 220101A ($10^4\lesssim\Delta T\lesssim10^7$ s) combining multi-wavelength data from soft X-rays until 6 GHz. The afterglow light curves in both X-ray and optical show distinct…
I review the main observational achievements concerning GRB optical afterglows occurred in the past two years. Their emission seems to be well interpreted in terms of the `fireball' model, although a variety of behaviours are observed.…
We present broad-band radio observations of the afterglow of GRB000301C, spanning from 1.4 to 350 GHz for the period of 3 to 83 days after the burst. This radio data, in addition to measurements at the optical bands, suggest that the…
We show that simple kinematic arguments can give limits on the timescale and amplitude of variabilities in gamma-ray burst (GRB) afterglows, especially when the variability timescale is shorter than the observed time since the burst \Delta…
Observations of gamma ray bursts (GRBs) with Swift produced the initially surprising result that many bursts have large X-ray flares superimposed on the underlying afterglow. These flares were sometimes intense, rapid, and late relative to…
Radio observations of gamma-ray burst (GRB) afterglows are essential for our understanding of the physics of relativistic blast waves, as they enable us to follow the evolution of GRB explosions much longer than the afterglows in any other…
The optical afterglows of gamma-ray bursts can be used to probe the physics, geometry, and environments of gamma-ray bursts. In this article I discuss the how spectra and photometry can be used to constrain fireball parameters, describe…
Radio observations of gamma-ray burst (GRB) afterglows provide both complementary and unique diagnostics of the afterglow physics and environment of the burst. Here we concentrate on three unique aspects of GRB energetics and environments…
Radio observations of gamma-ray burst (GRB) afterglows are essential for our understanding of the physics of relativistic blast waves, as they enable us to follow the evolution of GRB explosions much longer than the afterglows in any other…
Millisecond pulsars with strong magnetic fields may be formed through several processes, e.g. accretion-induced collapse of magnetized white dwarfs, merger of two neutron stars. During the birth of such a pulsar, an initial fireball…
Based on the refined dynamical model proposed by us earlier for beamed $\gamma$-ray burst ejecta, we carry out detailed numerical procedure to study those $\gamma$-ray bursts with rapidly fading afterglows (i.e., $\sim t^{-2}$). It is found…
Sharp breaks have been observed in the afterglow light curves of several GRBs; this is generally explained by the jet model. However, there are still some uncertainties concerning this interpretation due to the unclear hydrodynamics of jet…
We present a sample of radio afterglow light curves with measured decay slopes which show evidence for a flattening at late times compared to optical and X-ray decay indices. The simplest origin for this behavior is that the change in slope…
The rebrightening phenomenon is an interesting feature in some X-ray, optical, and radio afterglows of gamma-ray bursts (GRBs). Here, we propose a possible energy-supply assumption to explain the rebrightenings of radio afterglows, in which…
We report on the BeppoSAX and multiwavelength data analysis of the afterglow of Gamma-Ray Burst (GRB) 990123. Mainly due to its exceptional brightness, this is the only source for which the Wide Field Cameras have allowed an early detection…
We report the best evidence to date of a jet break in a short Gamma-Ray Burst (GRB) afterglow, using Chandra and Swift XRT observations of the X-ray afterglow of GRB 051221A. The combined X-ray light curve, which has three breaks, is…