Related papers: Two-shell collisions in the GRB afterglow phase
Recent observations suggest that $\gamma$-ray bursts (GRBs) and their afterglows are produced by jets of highly relativistic cannonballs (CBs), emitted in supernova (SN) explosions. The CBs, reheated by their collision with the shell, emit…
Gamma-ray bursts and their afterglows are thought to be produced by an ultrarelativistic jet. One of the most important open questions is the outflow composition: the energy may be carried out from the central source either as kinetic…
The afterglow of a gamma-ray burst (GRB) is commonly thought to be due to continuous deceleration of a relativistically expanding fireball in the surrounding medium. Assuming that the expansion of the fireball is adiabatic and that the…
We consider models for gamma-ray bursts in which a collimated jet expands either into a homogeneous medium or into a stellar wind environment, and calculate the expected afterglow temporal behavior. We show that (i) following a break and a…
Gamma-ray bursts (GRBs) are the most energetic phenomena in the Universe, characterized by prompt gamma-ray emission followed by multiwavelength afterglows. X-ray flares, observed during the afterglow phase, are generally believed to…
We use a sample of 19 Gamma Ray Bursts (GRBs) that exhibit single-peaked optical light curves to test the standard fireball model by investigating the relationship between the time of the onset of the afterglow and the temporal rising…
X-ray flashes (XRFs) and X-ray rich gamma-ray bursts (XRGRBs) share many observational characteristics with long duration GRBs, but the reason for which their prompt emission peaks at lower photon energies, $E_p$, is still under debate.…
The energetics of optical and radio afterglows following BeppoSAX and BATSE gamma-ray bursts (GRBs) suggests that gamma-ray emission is not narrowly collimated, but a moderate beaming is possible, so the total energy of a GRB may be in the…
The Second Gamma-ray Burst Catalog (2FLGC) was announced by the Fermi Large Area Telescope (Fermi-LAT) Collaboration. It includes 29 bursts with photon energy higher than 10 GeV. Gamma-ray burst (GRB) afterglow observations have been…
Millisecond pulsars with strong magnetic fields may be formed through several processes, e.g. accretion-induced collapse of magnetized white dwarfs, merger of two neutron stars. During the birth of such a pulsar, an initial fireball…
The main FRB event may leave behind a clump of relativistic plasma with high ``free energy'' density. As the plasma undergoes collisionless relaxation, it emits coherent electromagnetic waves. These electromagnetic waves may be observable…
The initial burst of a gamma ray burst (GRB) is usually followed by a longer-lived afterglow emitted at longer wavelengths. The evidence for a physical connection between GRBs and core collapse supernovae (SN) has increased since the…
We analyze the early X-ray flares in the GRB "flare-plateau-afterglow" (FPA) phase observed by Swift-XRT. The FPA occurs only in one of the seven GRB subclasses: the binary-driven hypernovae (BdHNe). This subclass consists of long GRBs with…
We present the early radio detection and multi-wavelength modeling of the short gamma-ray burst (GRB) 231117A at redshift $z=0.257$. The Australia Telescope Compact Array automatically triggered a 9-hour observation of GRB 231117A at 5.5…
Gamma-ray bursts early afterglows are important tracers for determining the radial structure and magnetization of the ejecta. In this paper, we focus on GRB 110213A that shows double-peaked optical afterglow lightcurves and the shallow…
The merger of a binary of neutron stars provides natural explanations for many of the features of short gamma-ray bursts (SGRBs), such as the generation of a hot torus orbiting a rapidly rotating black hole, which can then build a magnetic…
We severely criticize the consuetudinary analysis of the afterglows of gamma-ray bursts (GRBs) in the conical-ejection fireball scenarios. We argue that, instead, recent observations imply that the long-duration GRBs and their afterglows…
Recent detections of gamma-ray bursts (GRBs) at TeV energies opened new prospects for investigating radiative environments and particle acceleration mechanisms under extreme conditions. In this paper, we study the afterglows of these GRBs -…
We consider the effects of inverse Compton scattering of synchrotron photons from relativistic electrons in GRB afterglows. We compute the spectrum of the inverse Compton emission and find that it can dominate the total cooling rate of the…
In gamma-ray-bursts (GRB), ultra-relativistic blast waves are ejected into the circumburst medium. We analyse in unprecedented detail the deceleration of a self-similar Blandford-McKee blast wave from a Lorentz factor 25 to the…