Related papers: A Canonical High Energy Afterglow Emission Light C…
In this paper we present the spectrum of synchro-curvature self-Compton (SCSC) radiation of relativistic electrons with a power-law distribution of Lorentz factors. We find that the resulting spectrum is significantly different from that of…
Cosmological fireball models of gamma-ray bursts (GRBs) predict delayed emission, ``after-glow,'' at longer wavelengths. We present several new results regarding the model predictions, and show that X-ray to optical observations of…
GRB 980923 was one of the brightest bursts observed by the Burst and Transient Source Experiment (BATSE). Previous studies have detected two distinct components in addition to the main prompt episode, which is well described by a Band…
The MAGIC observations of late sub-TeV photons from GRB190114C enable us, for the first time, to determine the details of the emission process in a GRB afterglow and to pin down the physical parameters, such as the bulk Lorentz factor and…
Gamma-ray burst (GRB) prompt emission is commonly attributed to non-thermal radiation processes operating in the optically thin regions of a relativistic outflow. Among these, optically thin inverse-Compton (IC) scattering remains an…
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. The flares were sometimes intense, had rapid rise and decay…
There is now compelling evidence of a link between long-duration gamma-ray bursts (GRBs) and Type Ib/c supernovae (SNe). These core-collapse explosions are conjectured to radiate an anisotropic, beamed component associated with a…
We discuss the effects of synchrotron self-absorption in the prompt emission from the reverse shock of GRB afterglows occurring in a dense environment, such as the wind of a massive stellar progenitor or a dense ISM in early galaxies. We…
In the cosmological blast-wave model for gamma ray bursts (GRBs), high energy (> 10 GeV) gamma-rays are produced either through Compton scattering of soft photons by ultrarelativistic electrons, or as a consequence of the acceleration of…
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…
The synchrotron self-Compton (SSC) emission from Gamma-ray Burst (GRB) forward shock can extend to the very-high-energy (VHE; $E_\gamma > $100 GeV) range. Such high energy photons are rare and are attenuated by the cosmic infrared…
The principal paradigm for the prompt emission of gamma-ray bursts invokes diffusive acceleration at shocks internal to the dynamic ultrarelativistic outflow. This paper explores expectations for burst emission spectra arising from shock…
Highly variable gamma-ray pulses and X-ray flares in GRB light curves can result from external shocks rather than central engine activity under the assumption that the GRB blast-wave shell does not spread. Acceleration of cosmic rays to…
We discuss the spectrum arising from synchrotron emission by fast cooling (FC) electrons, when fresh electrons are continually accelerated by a strong blast wave, into a power law distribution of energies. The FC spectrum was so far…
The detection of the 100 GeV-TeV emission by a gamma-ray burst (GRB) will provide an unprecedented opportunity to study the nature of the central engine and the interaction between the relativistic flow and the environment of the burst's…
An equation is derived to calculate the dynamics of relativistic magnetized plasma which decelerates by sweeping up matter from the ISM. Reduction to the non-radiative and radiative regimes is demonstrated. The evolving electron momentum…
Models for gamma-ray burst afterglow dynamics and synchrotron spectra are known to exhibit various scale invariances, owing to the scale-free nature of fluid dynamics and the power-law shape of synchrotron spectra. Since GRB 170817A,…
The exact profile of a gamma-ray burst (GRB) afterglow image on the plane of the sky can provide important constraints on the underlying physics. In particular, it can test whether the magnetic field in the emitting shocked external medium…
We present results of Swift optical, UV and X-ray observations of the afterglow of GRB 050801. The source is visible over the full optical, UV and X-ray energy range of the Swift UVOT and XRT instruments.Both optical and X-ray lightcurves…
Gamma-ray bursts (GRBs) are fascinating extragalactic objects. They represent a fantastic opportunity to investigate unique properties not exhibited in other sources. Multi-wavelength afterglow observations from some short- and…