Related papers: Afterglow Light Curves and Broken Power Laws: A St…
The most luminous GRBs can be explained in terms of models involving stellar mass central engines only if the ejecta are beamed. As was pointed out by Rhoads, the dynamics of the blast wave, formed by the beamed ejecta sweeping the external…
The standard model of afterglow production by the forward shock wave is not supported by recent observations. We propose a model in which the forward shock is invisible and afterglow is emitted by a long-lived reverse shock in the burst…
Electrons accelerated in relativistic collisionless shocks are usually assumed to follow a power-law energy distribution with an index of $p$. Observationally, although most gamma-ray bursts (GRBs) have afterglows that are consistent with…
We derive a relation between the flux density $F_{\nu,j}$ at the light-curve break of a gamma-ray burst (GRB) afterglow and the break time $t_{j}$. The break is due to the transition from the spherical-like to jet-like evolution of the…
In models for gamma ray burst afterglows, it is normally assumed that the external shock strongly amplifies the magnetic field and that this field maintains a steady value throughout the shocked region. We discuss the effects of modifying…
The complex structure of the light curves of Swift GRBs has made the identification of breaks, and the interpretation of the blast wave caused by the burst, more difficult than in the pre-Swift era. We aim to identify breaks, which are…
The afterglow of GRB 170817A has been detected for more than three years, but the origin of the multi-band afterglow light curves remains under debate. A classical top-hat jet model is faced with difficulties in producing a shallow rise of…
We study an extensive sample of 87 GRBs for which there are well sampled and simultaneous optical and X-ray light-curves. We extract the cleanest possible signal of the afterglow component, and compare the temporal behaviors of the X-ray…
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…
Gamma-ray bursts (GRBs) and double neutron-star merger gravitational wave events are followed by afterglows that shine from X-rays to radio, and these broadband transients are generally interpreted using analytical models. Such models are…
We present optical, near-infrared, and X-ray observations of the optical afterglow (OA) of the X-ray rich, long-duration gamma-ray burst GRB 011211. Hubble Space Telescope (HST) data obtained 14, 26, 32, and 59 days after the burst, show…
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,…
Using the generic hydrodynamic model of Gamma-Ray Burst (GRB) afterglows, we calculate the radio afterglow light curves of low luminosity, high luminosity, failed and standard GRBs in different observational bands of FAST's energy window.…
We investigate the expected radio emission from the reverse shock of short GRBs, using the afterglow parameters derived from the observed short GRB light curves. In light of recent results suggesting that in some cases the radio afterglow…
Gamma-ray burst (GRB) afterglow emission can be observed from sub-TeV to radio wavelengths, though only 6.6\% of observed GRBs present radio afterglows. We examine GRB radio light curves (LCs) to look for the presence of radio plateaus,…
We present a method to estimate the jet opening angles of long duration Gamma-Ray Bursts (GRBs) using the prompt gamma-ray energetics and an inversion of the Ghirlanda relation, which is a correlation between the time-integrated peak energy…
Gamma-ray burst (GRB) afterglow light curves and spectra provide information about the density of the environment, the energy of the explosion, the properties of the particle acceleration process, and the structure of the decelerating jet.…
We investigate stellar microlensing of the collimated gamma-ray burst afterglows. A spherical afterglow appears on the sky as a superluminally expanding thin ring (``ring-like'' image), which is maximally amplified as it crosses the lens.…
Gamma-Ray Burst (GRB) afterglows are well described by synchrotron emission from relativistic blast waves expanding into an external medium. The blast wave is believed to amplify the magnetic field and accelerate the electrons into a power…
Gravitational-wave detected neutron star mergers provide an opportunity to investigate short gamma-ray burst (GRB) jet afterglows without the GRB trigger. Here we show that the post-peak afterglow decline can distinguish between an…