Related papers: Gamma Ray Bursts
The recent progress in the understanding the physical nature of neutron star equilibrium configurations and the first observational evidence of a genuinely short gamma-ray burst, GRB 090227B, allows to give an estimate of the gravitational…
Fast radio bursts (FRBs) are one of the most exciting new mysteries of astrophysics. Their origin is still unknown, but recent observations seem to link them to soft gamma repeaters and, in particular, to magnetar giant flares (MGFs). The…
It is known that the high energy $(> 100\,\text{MeV})$ emission of gamma-ray bursts is delayed with respect to the low energy emission. However, the dependence of light curves on energy has not been studied for the high energy bands. In…
Recent Fermi results have focused attention on gamma-ray burst's (GRB) prompt emission phase, which is rich in phenomenology and poorly understood. The broad band spectra observed by Fermi does not fit into any of the frameworks of existing…
Typical observational gamma-ray burst (GRB) spectra are discussed and, in this connection, what is the origin of the compactness problem and how it was solved at first. If the threshold for $e^{-}e^{+}$ pair production depends on an angle…
Gamma-ray bursts are transient events from beyond the solar system. Besides the allure of their mysterious origin, bursts are physically fascinating because they undoubtedly require exotic physics. Optical transients coincident with burst…
We provide a comprehensive review of major developments in our understanding of gamma-ray bursts, with particular focus on the discoveries made within the last fifteen years when their true nature was uncovered. We describe the…
The energy of a Gamma-Ray Burst is one of the most interesting factors that can help determining the origin of these mysterious explosions. After the discovery that GRBs are cosmological it was thought, for a while that they are standard…
The propagation of gamma-rays over cosmological distances is the subject of extensive theoretical and observational research at GeV and TeV energies. The mean free path of gamma-rays in the cosmic web is limited above 100 GeV due to the…
Mirror matter models have been suggested recently as an explanation of neutrino puzzles and microlensing anomalies. We show that mirror supernovae can be a copious source of energetic gamma rays if one assumes that the quantum gravity scale…
In the last few years the Fermi -LAT instrument has detected GeV gamma-ray emission from a few novae. Such GeV emission can be interpreted in terms of an inverse Compton process of electrons accelerated in a shock. It is expected that…
Gamma-ray bursts are a complex, non-linear system that evolves very rapidly through stages of vastly different conditions. They evolve from scales of few hundred kilometers where they are very dense and hot to cold and tenuous on scales of…
GRB 131108A is a bright long Gamma-Ray Burst (GRB) detected by the Large Area Telescope and the Gamma-ray Burst Monitor on board the Fermi Gamma-ray Space Telescope. Dedicated temporal and spectral analyses reveal three $\gamma$-ray flares…
Since the launch of the Fermi Gamma-ray Space Telescope on 11 June 2008, significant detections of high energy emission have been reported only in six Gamma-ray Bursts (GRBs) until now. In this work we show that the lack of detection of a…
Gamma-ray bursts have the potential to produce the particle energies (up to $10^{21}$ eV) and the energy budget ($10^{44} \rm{erg yr^{-1} Mpc^{-3}}$) to accommodate the spectrum of the highest energy cosmic rays; on the other hand, there is…
We calculate the synchrotron self-Compton emission from internal shocks occurring in relativistic winds as a source of gamma-ray bursts, with allowance for self-absorption. For plausible model parameters most pulses within a Gamma-Ray Burst…
Based on the experience gained during the four and a half years of the mission, the Fermi -LAT collaboration has undertaken a comprehensive revision of the event-level analysis going under the name of Pass 8. Although it is not yet…
The Fermi Gamma-ray Space Telescope was launched more than 13 years ago and since then it has dramatically changed our knowledge of the gamma-ray sky. With more than three billions photons from the whole sky, collected in the energy range…
Gamma ray burst sources are isotropically distributed. They could be located at distances $\sim 1000$ AU. (Katz \cite{JK92}) GRB signals have many narrow peaks that are unresolved at the millisecond time resolution of existing observations.…
Fermi satellite discovered that cosmological gamma-ray bursts (GRBs) are accompanied by long GeV flashes. In two GRBs, an optical counterpart of the GeV flash has been detected. Recent work suggests that the GeV+optical flash is emitted by…