Related papers: Synchrotron Self Absorption in GRB Afterglow
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…
GRB afterglow 090510 is (so far) the best-monitored afterglow in the optical, X-ray, and above 100 MeV, measurements covering 2-3 decades in time at each frequency. Owing to its power-law temporal decay and power-law spectrum, it seems very…
We report our discovery and early time optical, near-infrared, and radio wavelength follow-up observations of the afterglow of the gamma-ray burst GRB 021211. Our optical observations, beginning 21 min after the burst trigger, demonstrate…
We consider here a proton-synchrotron model to explain the MAGIC observation of GRB 190114C afterglow in the energy band $0.2 - 1$~TeV, while the X-ray spectra are explained by electron-synchrotron emission. Given the uncertainty of the…
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…
A generic synchrotron external shock model is the widely preferred paradigm used to interpret the broad-band afterglow data of gamma-ray bursts (GRBs), including predicted observable signatures from a reverse shock which have been confirmed…
We present a comprehensive multi-wavelength study of GRB 260310A / SN 2026fgk, a nearby ($z=0.153$), long-duration gamma-ray burst (GRB) with an exceptionally underluminous prompt $\gamma$-ray emission and a Comptonized spectrum. It is…
The luminosity and the spectral distribution of the afterglow of GRB 031203 have been presented within our theoretical framework, which envisages the GRB structure as composed by a proper-GRB, emitted at the transparency of an…
Early optical observations of gamma-ray bursts can significantly contribute to the study of the central engine and physical processes therein. However, of the thousands observed so far, still only a few have data at optical wavelengths in…
Synchrotron emission is believed to be a major radiation mechanism during gamma-ray bursts' (GRBs) prompt emission phase. A significant drawback of this assumption is that the theoretical predicted spectrum, calculated within the framework…
Reverse shock (RS) emission from Gamma Ray Bursts is an important tool in investigating the nature of the ejecta from the central engine. If the ejecta magnetization is not high enough to suppress the RS, a strong RS emission component,…
We describe our attempt to determine if gamma-ray burst (GRB) and afterglow emissions could both arise in external shocks for simple GRBs--bursts consisting of just a few peaks in their lightcurves. We calculate peak flux and peak frequency…
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…
Gamma-ray burst (GRB) afterglow emission is believed to be produced by synchrotron emission of electrons accelerated to high energy by a relativistic collisionless shock propagating into a weakly magnetized plasma. Afterglow observations…
We calculate the GeV afterglow emission expected from a few mechanisms related to GRBs and their afterglows. Given the brightness of the early X-ray afterglow emission measured by Swift/XRT, GLAST/LAT should detect the self-Compton emission…
The curvature of a relativistic blast wave implies that its emission arrives to observers with a spread in time. This effect is believed to wash out fast variability in the lightcurves of GRB afterglows. We note that the spreading effect is…
The optical and gamma-ray observations of GRB 080319B allow us to determine a fairly complete physical picture for this remarkable burst. The data indicate that the prompt optical and gamma-ray photons were produced at the same location but…
We present the first results of a program to systematically study the optical-to-X-ray spectral energy distribution (SED) of Swift GRB afterglows with known redshift. The goal is to study the properties of the GRB explosion and of the…
A theoretical attempt to identify the physical process responsible for the afterglow emission of Gamma-Ray Bursts (GRBs) is presented, leading to the occurrence of thermal emission in the comoving frame of the shock wave giving rise to the…
GRB 140903A, a short duration $\gamma-$ray burst (SGRB) detected by {\it Swift}, is characterized by its long-lasting radio emission among SGRBs. In addition to the $\sim 10^{6}$ s radio afterglow emission, the afterglow of GRB 140903A…