Related papers: Energy Injection in GRB Afterglow Models
We present the recent discovery of linear polarization of the optical afterglow of GRB 990510. Effects that could introduce spurious polarization are discussed, showing that they do not apply to the case of GRB 990510, which is then…
We present numerical simulations of Gamma-Ray Bursts arising from external shocks in the impulsive and wind models, including a weak or a strong coupling between electrons and protons plus magnetic fields, and analyze the burst features in…
We present a densely sampled R-band light curve of the optical afterglow of GRB 030329 obtained during the period 15.5-23 hours after the burst. This dataset allows us to search for short time-scale fluctuations that must be present at some…
Observations of long duration gamma-ray bursts (GRBs) with TeV emission during their afterglow have been on the rise. Recently, GRB 221009A, the most energetic GRB ever observed, was detected by the {LHAASO} experiment in the energy band…
We present radio, optical/NIR, and X-ray observations of the afterglow of the short-duration 130603B, and uncover a break in the radio and optical bands at 0.5 d after the burst, best explained as a jet break with an inferred jet opening…
We present a complete sample of 29 GRBs for which it has been possible to determine temporal breaks (or limits) from their afterglow light curves. We interpret these breaks within the framework of the uniform conical jet model,…
In order to assist in planing the search of supernova (SN) in the late time afterglow (AG) of the gamma ray burst (GRB) 011121 we use the Cannonball Model of GRBs and the observations of its afterglow in the R band in the first two days to…
We present X-ray to radio frequency observations of the bright long gamma-ray burst GRB 210702A. Our ALMA 97.5 GHz observations show a significant rebrightening by a factor of ~2 beginning at 8.2 days post-burst and rising to peak…
We have found that the conventional generic dynamical model for gamma-ray bursts (GRBs) cannot reproduce the Sedov solution in the non-relativistic limit. Based on our refined generic dynamical model, we investigate afterglows from jetted…
Plateau features are frequently observed in the afterglows of gamma-ray bursts (GRBs), yet their physical origins remain under debate. In this work, we compile a sample of 124 GRBs with known redshifts and simultaneous X-ray and optical…
We explore the influence of the full curvature effect on the flux of early X-ray afterglow of gamma-ray bursts (GRBs) in cases when the spectrum of the intrinsic emission is a power-law. We find that the well-known $t^{-(2+\beta)}$ curve is…
The cosmological gamma-ray burst (GRB) phenomenon is reviewed. The broad observational facts and empirical phenomenological relations of the GRB prompt emission and afterglow are outlined. A well-tested, successful fireball shock model is…
The parameters of the GRB 000301c afterglow are determined within the usual framework of synchrotron emission from relativistic ejecta, through fits to the available radio-to-optical data. It is found that 1) the jet energy after the GRB…
A nascent magnetar, accompanying a gamma-ray burst (GRB) explosion, releases enormous rotational energy via magnetic dipole radiation. The energy loss rate of the magnetar is determined by the strength of the magnetic field at the pole. We…
Context: Multiwavelength observations of gamma-ray burst prompt and afterglow emission are a key tool to disentangle the various possible emission processes and scenarios proposed to interpret the complex gamma-ray burst phenomenology.…
We identify the fading X-ray afterglow of GRB 001025A from XMM-Newton observations obtained 1.9-2.3 days, 2 years, and 2.5 years after the burst. The non-detection of an optical counterpart to an upper limit of R=25.5, 1.20 days after the…
Extensive observational campaigns of afterglow hunting have greatly enriched our understanding of the gamma-ray burst (GRB) phenomenon. Efforts have been made recently to explore some afterglow properties or signatures that will be tested…
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…
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…
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…