Related papers: Prompt GeV emission in the synchrotron self-Compto…
The gamma-ray burst (GRB) 060218/SN 2006aj is a peculiar event, with the second lowest redshift, low luminosity, long duration, chromatic lightcurve features, and in particular, the presence of a thermal component in the X-ray and…
Recent detection of sub-TeV emission from gamma-ray bursts (GRBs) represents a breakthrough in the GRB study. The multi-wavelength data of the afterglows of GRB 190114C support the synchrotron self-Compton (SSC) origin for its sub-TeV…
In this paper we study synchrotron and synchrotron self Compton (SSC) emission from internal shocks (IS) during the prompt and X-ray flare phases of Gamma-Ray Bursts (GRBs). The aim is to test the IS model for the flare emission and for…
Several high-frequency peaked BL Lac objects such as Mrk 501 are strong TeV emitters. However, a significant fraction of the TeV gamma rays emitted are likely to be absorbed in interactions with the diffuse IR background, yielding…
The prompt optical emission that arrives with gamma-rays from a cosmic gamma-ray burst (GRB) is a signature of the engine powering the burst, the properties of the ultra-relativistic ejecta of the explosion, and the ejecta's interactions…
Very-high-energy (VHE; $\geq 10$ GeV) photons are expected from the nearest and brightest Gamma-ray bursts (GRBs). VHE photons, at energies higher than 300 GeV, were recently reported by the MAGIC collaboration for this burst. Immediately,…
The radiative process responsible for gamma-Ray Burst (GRB) prompt emission has not been identified yet. If dominated by fast-cooling synchrotron radiation, the part of the spectrum immediately below the $\nu F_\nu$ peak energy should…
The mechanism that causes the prompt-emission episode of gamma-ray bursts (GRBs) is still widely debated despite there being thousands of prompt detections. The favoured internal shock model relates this emission to synchrotron radiation.…
Very-high-energy (VHE) emission is usually interpreted in the synchrotron-self Compton (SSC) scenario, and expected from the low-redshift and high-luminosity gamma-ray bursts (GRBs), as GRB 180720B and GRB 190114C. Recently, VHE emission…
Gamma-ray bursts (GRBs) have been considered as potential very high-energy photon emitters due to the large amount of energy released as well as the strong magnetic fields involved in their jets. However, the detection of TeV photons is not…
The principal paradigm for gamma-ray bursts (GRBs) suggests that the prompt transient gamma-ray signal arises from multiple shocks internal to the relativistic expansion. This paper explores how GRB prompt emission spectra can constrain…
Recent observations of Gamma-Ray Bursts (GRBs) by the Fermi Large Area Telescope (LAT) revealed a power law decay feature of the high energy emission (above 100 MeV), which led to the suggestion that it originates from a (probably…
Gamma-ray bursts (GRBs) are among the most luminous sources in the universe. The nature of their emission at TeV energies is one of the most relevant open issues related to these events. The temporal and spectral features inferred from the…
Optical observations of gamma-ray bursts (GRBs) contemporaneous with their prompt high-energy emission are rare, but they can provide insights into the physical processes underlying these explosive events. The Transiting Exoplanet Survey…
We calculate the very high energy (sub-GeV to TeV) inverse Compton emission of GRB afterglows. We argue that this emission provides a powerful test of the currently accepted afterglow model. We focus on two processes: synchrotron…
We study the time-resolved spectra of eight GRBs observed by Fermi GBM in its first five years of mission, with 1 keV - 1 MeV fluence $f>1.0\times10^{-4}$ erg cm$^{-2}$ and signal-to-noise level $\text{S/N}\geq10.0$ above 900 keV. We aim to…
We calculate the spectra of inverse Compton (IC) emissions in gamma-ray burst (GRB) shocks produced when relativistic ejecta encounters the external interstellar medium, assuming a broken power-law approximation to the synchrotron seed…
The mechanism responsible for the prompt emission of gamma-ray bursts (GRBs) is still a debated issue. The prompt phase-related GRB correlations can allow to discriminate among the most plausible theoretical models explaining this emission.…
The recent and brightest GRB 221009A observed by LHAASO marked the first detection of the onset of TeV afterglow, with a total of 7 GRBs exhibiting very high energy (VHE) afterglow radiation. However, consensus on VHE radiation of GRBs is…
In recent years, our understanding of gamma-ray bursts (GRB) prompt emission has been revolutionized, due to a combination of new instruments, new analysis methods and novel ideas. In this review, I describe the most recent observational…