Related papers: Synchrotron Self-Compton Emission in the Two-Compo…
Gamma-ray bursts (GRBs) comprise of short, bright, energetic flashes of emission from extragalactic sources followed by a longer afterglow phase of decreased brightness. Recent discoveries of very-high-energy (VHE, $\gtrsim 100$ GeV)…
Recently gamma-ray bursts (GRBs) have been detected at very high-energy (VHE) gamma-rays by imaging atmospheric Cherenkov telescopes, and a two-component jet model has often been invoked to explain multiwavelength data. In this work,…
Long-duration gamma-ray bursts (GRBs) originate from ultra-relativistic jets launched from the collapsing cores of dying massive stars. They are characterised by an initial phase of bright and highly variable radiation in the keV-MeV band…
In recent years, afterglow emission in the very-high-energy (VHE) band above 100 GeV has been clearly detected for at least five gamma-ray bursts (GRBs 180720B, 190114C, 190829A, 201216C and 221009A). For some of these VHE GRBs, we…
Recently, ground-based Imaging Atmospheric Cherenkov Telescopes have reported the detection of very-high-energy (VHE) gamma-rays from some gamma-ray bursts (GRBs). One of them, GRB~190829A, was triggered by the Swift satellite, and about…
Gamma-ray bursts (GRBs) are brief flashes of gamma rays, considered to be the most energetic explosive phenomena in the Universe. The emission from GRBs comprises a short (typically tens of seconds) and bright prompt emission, followed by a…
Gamma-ray bursts (GRB) are short and intense bursts of $\sim$100 keV$-$1MeV photons, usually followed by long-lasting decaying afterglow emission in a wide range of electromagnetic wavelengths from radio to X-ray and, sometimes, even to GeV…
The afterglow emission from gamma-ray bursts (GRBs) is believed to originate from a relativistic blast wave driven into the circumburst medium. Although the afterglow emission from radio up to X-ray frequencies is thought to originate from…
A growing number of gamma-ray burst (GRB) afterglows is observed at very-high energies (VHE, $\gtrsim 100$ GeV). Yet, our understanding of the mechanism powering the VHE emission remains baffling. We make use of multi-wavelength…
Gamma-ray bursts (GRBs) 201015A and 201216C are valuable cases with detection of very high energy (VHE) gamma-ray afterglows. By analysing their prompt emission data, we find that GRB 201216C is an extremely energetic long GRB with a hard…
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.…
Gamma-ray Bursts (GRBs) generate powerful relativistic jets that inject a large amount of energy into their surrounding environment, producing blast waves that accelerate particles to high energies. The GRB afterglow radiation provides a…
The recent detection of very high energy (VHE, $\gtrsim$ 100 GeV) $\gamma$-ray emission from gamma-ray bursts (GRBs) has provided new insights into afterglow physics. Understanding the temporal and spectral evolution of VHE GRBs requires…
Gamma-ray bursts (GRBs), which are bright flashes of gamma rays from extragalactic sources followed by fading afterglow emission, are associated with stellar core collapse events. We report the detection of very-high-energy (VHE) gamma rays…
The detection of multi-TeV gamma-rays from the afterglow phase of GRB 190829A by High Energy Stereoscopic System (H.E.S.S.) telescope is an addition to the already existing list of two more GRBs observed in the very high energy (VHE)…
Recent observational and theoretical studies have raised the possibility that the collimated outflows in gamma-ray burst (GRB) sources have two distinct components: a narrow (opening half-angle $\theta_{\rm n}$), highly relativistic…
Long duration gamma ray bursts (GRBs) and X-ray flashes (XRFs) are produced by highly- relativistic jets ejected in core-collapse supernova explosions. The origin of short hard gamma-ray bursts (SHBs) has not been established. They may be…
High energy emission (> tens MeV) of Gamma-Ray Bursts (GRBs) provides an important clue to understand the physical processes involved in GRBs, which may be correlated with the GRB early afterglow. A shallow decline phase has been well…
Long GRB 190114C, identified on January 14th, 2019, was the first Gamma-ray Burst that substantially violated the defined 10 GeV energy limit of the Synchrotron model, with an observed emission between 0.2 - 1 TeV and a low redshift of z =…
Gamma-ray bursts (GRBs) and following afterglows are considered to be produced by dissipation of kinetic energy of a relativistic fireball and radiation process is widely believed as synchrotron radiation or inverse Compton scattering of…