Related papers: Gamma-ray burst afterglow light curves from a Lore…
We present the systematic analysis of the UVOT and XRT light curves for a sample of 26 Swift Gamma-Ray Bursts (GRBs). By comparing the optical/UV and X-ray light curves, we found that they are remarkably different during the first 500s…
In this paper, within the popular internal shock scenario of GRBs, we calculate the early optical afterglow lightcurves of a neutron-fed GRB fireball for different assumed neutron fractions in the fireball and for both ISM- and…
The afterglow of GRBs is believed to originate from the synchrotron emission of shock-accelerated electrons produced by the interaction between the outflow and the external medium. The accelerated electrons are usually assumed to follow a…
We investigate the dynamics and afterglow light curves of gamma-ray burst (GRB) blast waves that encounter various density structures (such as bumps, voids, or steps) in the surrounding ambient medium. We present and explain the…
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…
The bright gamma-ray burst GRB050525a has been detected with the Swift observatory, providing unique multiwavelength coverage from the very earliest phases of the burst. The X-ray and optical/UV afterglow decay light curves both exhibit a…
Due to some refinements in the dynamics, we can follow the overall evolution of a realistic jet numerically till its bulk velocity being as small as $\beta c \sim 10^{-3} c$. We find no obvious break in the optical light curve during the…
We present an analysis of the unusual optical light curve of the gamma-ray burst GRB~081029, which occurred at a redshift of z = 3.8479$. We combine X-ray and optical observations from the Swift X-Ray Telescope and the Swift…
We present a study of the intermediate regime between ultra-relativistic and nonrelativistic flow for gamma-ray burst afterglows. The hydrodynamics of spherically symmetric blast waves is numerically calculated using the AMRVAC adaptive…
The discovery of the short GRB 090510 has raised considerable attention mainly because it had a bright optical afterglow and it is among the most energetic events detected so far within the entire GRB population. The afterglow was observed…
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 selected a sample of 33 Gamma Ray Bursts (GRBs) detected by Swift, with known redshift and optical extinction at the host frame. For these, we constructed the de-absorbed and K-corrected X-ray and optical rest frame light curves. These…
We present the observations of the afterglow of gamma-ray burst GRB 090102. Optical data taken by the TAROT, REM, GROND, together with publicly available data from Palomar, IAC and NOT telescopes, and X-ray data taken by the XRT instrument…
We present our centimeter wavelength (1.4, 2.3 and 4.8 GHz) light curves of the afterglow of GRB 030329, which were obtained with the Westerbork Synthesis Radio Telescope. Modeling the data according to a collimated afterglow results in a…
The power-law decay of the X-ray emission of GRB afterglows 050319, 050401, 050607, 050713A, 050802 and 050922C exhibits a steepening at about 1--4 hours after the burst which, surprisingly, is not accompanied by a break in the optical…
We use published data in radio, optical and X-ray bands to analyze and model afterglows of GW/GRB 170817A. Our analysis is based on a phenomenological gamma-ray burst generator model which we previously used to study the prompt gamma-ray…
We examine the Swift/X-ray Telescope (XRT) light curves from the first ~150 gamma-ray burst (GRB) afterglows. Although we expected to find jet breaks at typical times of 1-2 days after the GRB, we find that these appear to be extremely…
The X-ray light-curves of the GRB afterglows monitored by Swift display one to four phases of power-law decay. In chronological order they are: the burst tail, the "hump", the standard decay, and the post jet-break decay. The large-angle…
We investigate numerically the ability of three models (jet, structured outflow, energy injection) to accommodate the optical light-curve breaks observed in 10 GRB afterglows (980519, 990123, 990510, 991216, 000301c, 000926, 010222, 011211,…
We present the first statistical analysis of 27 UVOT optical/ultra-violet lightcurves of GRB afterglows. We have found, through analysis of the lightcurves in the observer's frame, that a significant fraction rise in the first 500s after…