Related papers: A Canonical High Energy Afterglow Emission Light C…
We study afterglow flares of gamma-ray bursts (GRBs) in the framework of the late internal shock (LIS) model based on a careful description for the dynamics of a pair of shocks generated by a collision between two homogeneous shells,.…
Recent results of the hectic research activity about gamma-ray bursts will be reviewed, with emphasis about the emission processes at the origin of the observed gamma-rays. The conventional synchrotron shock scenario is found to have…
We numerically simulate the gamma-ray burst (GRB) afterglow emission with a one-zone time-dependent code. The temporal evolutions of the decelerating shocked shell and energy distributions of electrons and photons are consistently…
The fireball model of gamma-ray bursts predicted that when the energetic blast wave encountered the surrounding medium, there will be afterglow emission, and the subsequent afterglow observations appeared to confirm this prediction. In this…
Gamma-ray Bursts (GRBs) are among the potential extragalactic sources of very-high-energy (VHE) gamma-rays. We discuss the prospects of detecting VHE gamma-rays with current ground-based Cherenkov instruments during the afterglow phase.…
Two radiation mechanisms, inverse Compton scattering (ICS) and synchrotron radiation (SR), suffice within the cannonball (CB) model of long gamma ray bursts (LGRBs) and X-ray flashes (XRFs) to provide a very simple and accurate description…
The emission mechanism of the gamma-ray bursts (GRBs) is still a matter of debates. The standard synchrotron energy spectrum of cooling electrons F_E ~ E^{-1/2} is much too soft to account for the majority of the observed spectral slopes.…
Synchrotron self-Compton (SSC) scattering is an important emission mechanism in many astronomical sources, such as gamma-ray bursts (GRBs) and active galactic nuclei (AGNs). We give a complete presentation of the analytical approximations…
Gamma-ray bursts (GRBs) are among the most luminous transients in the Universe and constitute prime targets for multimessenger studies, particularly in connection with gravitational-wave events. The detection of very-high-energy (TeV)…
We study synchrotron self-inverse Compton radiation from a reverse-shocked fireball. If the inverse Compton process dominates the cooling of shocked electrons, an X-ray flare produced by the first order Compton scattering would emerge in…
It has recently been proposed that ultrahigh energy ($\gtrsim 10^{19}$ eV) cosmic rays (UHECRs) are accelerated by the blast waves associated with GRBs. We calculate the observed synchrotron radiation spectrum from protons and energetic…
Gamma-ray bursts (GRBs) show diverse X-ray afterglow light-curves, including breaks and plateaus, whose physical origins remain debated. Previous claims linked high-energy ($E \ge 100$ MeV) detection to X-ray afterglow complexity or plateau…
According to current models, gamma-ray bursts (GRBs) are produced when the energy carried by a relativistic outflow is dissipated and converted into radiation. The efficiency of this process, $\epsilon_\gamma$, is one of the critical…
High energy photons (>100 MeV) are detected by the Fermi/LAT from GRB 130427A up to almost one day after the burst, with an extra hard spectral component being discovered in the high-energy afterglow. We show that this hard spectral…
The detection of TeV gamma-ray bursts (GRBs) brought new opportunities for studying the physics of particle acceleration at relativistic shocks. The \hess telescopes recently observed very-high-energy (VHE) emission from a nearby…
Observations of early afterglow emission from gamma-ray bursts (GRB's) with the Swift satellite show steep decay of the X-ray light curve, F_\nu(t) ~ t^{-\alpha} with \alpha ~ 2.5 - 4 at ~300-500 s after the burst trigger. The spectrum in…
Gamma-ray bursts (GRBs) are one of the most promising transient events for studying multi-wavelength observations in extreme conditions. Observation of GeV photons from bursts would provide crucial information on GRB physics, including the…
This paper is a brief review of the processes responsible for X-ray emission from radio jets, lobes and hot spots. Possible photons in inverse Compton scattering models include the radio synchrotron radiation itself (i.e. synchrotron…
We study high-energy gamma-ray afterglow emission from gamma-ray bursts (GRBs) in the prior emission model, which is proposed to explain the plateau phase of the X-ray afterglow. This model predicts the high-energy gamma-ray emission when…
Since its launch in 2004, the Swift satellite has monitored the X-ray afterglows of several hundred Gamma-Ray Bursts, and revealed that their X-ray light-curves are more complex than previously thought, exhibiting up to three power-law…