Related papers: From blast wave to observation
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…
We compute the afterglow of gamma-ray bursts produced by purely electromagnetic outflows to see if it shows characteristic signatures differing from those obtained with the standard internal/external shock model. Using a simple approach for…
The discovery of Gamma-Ray Burst (GRB) afterglows revealed a new class of variable sources at optical and radio wavelengths. At present, the environment and precise redshift of the detected afterglows are still unknown. We show that if a…
We numerically simulate the gamma-ray burst (GRB) afterglow emission with a one-zone time-dependent code. The temporal evolutions of the decelerating shocked shell and energy distributions of electrons and photons are consistently…
Gamma-ray bursts (GRBs) at high redshifts are expected to be gravitationally lensed by objects of different mass scales. Besides a single recent claim, no lensed GRB has been detected so far by using the gamma-ray data only. In this paper,…
We present extensive multi-colour (UBVR_CI_C) photometry of the optical afterglow of GRB 980519. Upon discovery, 8.3 hours after the burst, the source was decaying as a power law, (t-t_GRB)^alpha, with a rapid decay rate alpha_1 = -…
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 calculate the magnification light curves due to stellar microlensing of gamma-ray burst (GRB) afterglows. A GRB source appears on the sky as a thin ring which expands faster than the speed of light and is maximally magnified as it…
Based on a refined generic dynamical model, we investigate afterglows from jetted gamma-ray burst (GRB) remnants numerically. In the relativistic phase, the light curve break could marginally be seen. However, an obvious break does exist at…
Using the Swift data of GRB 050315, we progress on the uniqueness of our theoretically predicted Gamma-Ray Burst (GRB) structure as composed by a proper-GRB (P-GRB), emitted at the transparency of an electron-positron plasma with suitable…
When does a GRB stop and its afterglow begin? A GRB may be defined as emission by internal shocks and its afterglow as emission by an external shock, but it is necessary to distinguish them observationally. With these definitions…
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"…
Gamma-ray bursts (GRBs) are the most energetic explosions in the universe, and their afterglow emission provides an opportunity to probe the physics of relativistic shock waves in an extreme environment. Several key pieces for completing…
In a recent paper (Dai & Lu 1999), we have proposed a simple model in which the steepening in the light curve of the R-band afterglow of the gamma-ray burst (GRB) 990123 is caused by the adiabatic shock which has evolved from an…
Recent observations suggest that long-duration gamma-ray bursts (GRBs) and their afterglows are produced by highly relativistic jets emitted in core-collapse explosions. The pre-explosive ambient medium provides a natural test for the most…
The prompt emission of low-luminosity gamma-ray bursts (llGRBs) indicates that these events originate from a relativistic shock breakout. In this case we can estimate, based on the properties of the prompt emission, the energy distribution…
We present an analytical approach to calculate the hydrodynamics of the interaction between a relativistic ejecta and a surrounding medium, whose evolution serves as a model for Gamma-Ray Burst afterglows. We investigate the effect of the…
Observations of gamma-ray burst (GRB) afterglows have long provided the most detailed information about the origin of this spectacular phenomena. The model that is most commonly used to extract physical properties of the event from the…
Beginning with the $\gamma$-ray bursts GRB 970228 and GRB 970508, a standard model for the interpretation of GRB afterglows emerged involving synchrotron emission from a constant energy blast wave expanding into a constant density,…
Gamma-ray bursts (GRBs) are brief flashes of gamma rays, considered to be the most energetic explosive phenomena in the Universe. The emission from GRBs comprises a short (typically tens of seconds) and bright prompt emission, followed by a…