Related papers: Gravitational collapse as the source of gamma-ray …
To explain the extremely high energy release, $>10^{53}$~erg, suggested by the observations of some Gamma Ray Bursts (GRBs) we propose a new energy extraction mechanism from the rotation energy of a Kerr-Newman black hole (BH) by a massive…
Gamma Ray Bursts (GRBs) are among the most powerful sources in the Universe: they emit up to 10^54 erg in the hard X-ray band in few tens of seconds. The cosmological origin of GRBs has been confirmed by several spectroscopic measurements…
Most of proposed models of cosmological gamma-ray bursts (GRBs) are associated to gravitational collapses of massive stars, and hence evolution of the GRB rate, which is crucially important in GRB intensity distribution analysis, is…
Recent observations suggest that gamma ray bursts (GRBs) and their afterglows are produced by highly relativistic jets emitted in core collapse supernova explosions (SNe). The result of the event, probably, is not just a compact object plus…
The favored progenitor model for Gamma-ray Bursts (GRBs) with Supernova (SN) association is the core collapse of massive stars. One possible outcome of such a collapse is a rapidly spinning, strongly magnetized neutron star ("magnetar"). We…
There are about 2000 gamma ray burst (GRB) events known to us with data pouring in at the rate of one per day. While the afterglows of GRBs in radio, optical and X-ray bands are successfully explained by the fireball model, a significant…
This paper presents the theoretical basis of the fireball/blast wave model, and some implications of recent results on GRB source models and cosmic-ray production from GRBs. BATSE observations of the prompt gamma-ray luminous phase, and…
Gamma-Ray Bursts (GRBs) - short bursts of 100-1MeV photons arriving from random directions in the sky are probably the most relativistic objects discovered so far. Still, somehow they did not attract the attention of the relativistic…
Compact binary mergers, with neutron stars or neutron star and black-hole components, are thought to produce various electromagnetic counterparts: short gamma-ray bursts (GRBs) from ultra-relativistic jets followed by broadband afterglow;…
The recent localization of some short-hard gamma ray bursts (GRBs) in galaxies with low star formation rates has lent support to the suggestion that these events result from compact object binary mergers. We discuss how new simulations in…
Current understanding of core collapse and thermonuclear supernovae is reviewed. Recent progress in unveiling the nature of cosmic gamma-ray bursts (GRB) is discussed, with the focus on the apparent link of several GRBs with an energetic…
We propose that the gravitational collapse of supermassive objects ($ M\ga 10^4 M_\odot$), either as relativistic star clusters or as single supermassive stars (which may result from stellar mergers in dense star clusters), could be a…
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…
We review recent progress in our understanding of the nature of gamma ray bursts (GRBs) and in particular, of the relationship between short GRBs and long GRBs. The first example of a short GRB is described. The coincidental occurrence of a…
Photoexcitation and ionization of partially ionized heavy atoms in highly relativistic flows by interstellar photons, followed by their reemission in radiative recombination and decay, boost star-light into beamed $\gamma$ rays along the…
In the external shock model, gamma-ray burst (GRB) emissions are produced by the energization and deceleration of a thin relativistic blast wave due to its interactions with the circumburst medium (CBM). We study the physical properties of…
Binary neutron-star mergers have long been associated with short-duration gamma-ray bursts (GRBs). This connection was confirmed with the first coincident detection of gravitational waves together with electromagnetic radiation from…
The kinetic energy of supernovae (SNe) accompanied by gamma-ray bursts (GRBs) tends to cluster near E52 erg, with 2.E52 erg an upper limit to which no compelling exceptions are found (assuming a certain degree of asphericity), and it is…
From Galactic binary sources, to extragalactic magnetized neutron stars, to long-duration GRBs without associated supernovae, the types of sources we now believe capable of producing bursts of gamma-rays continues to grow apace. With this…
The Pseudo-Goldstone Boson (PGB) emission could provide a very efficient mechanism for explaining the cosmic Gamma Ray Bursts (GRBs). The PGBs could be produced during the merging of two compact objects like two neutron stars or neutron…