Astronomy and Astrophysics – Astrophysics
Scientific paper
1998-08-11
New Astron. 4 (1999) 303-312
Astronomy and Astrophysics
Astrophysics
submitted to New Astronomy, for the David N. Schramm memorial volume, 14 pages LaTeX, no figures, minor changes
Scientific paper
10.1016/S1384-1076(99)00013-5
A wide range of mechanisms have been proposed to supply the energy for gamma-ray bursts (GRB) at cosmological distances. It is a common misconception that some of these, notably NS-NS mergers, cannot meet the energy requirements suggested by recent observations. We show here that GRB energies, even at the most distant redshifts detected, are compatible with current binary merger or collapse scenarios involving compact objects. This is especially so if, as expected, there is a moderate amount of beaming, since current observations constrain the energy per solid angle much more strongly and directly than the total energy. All plausible progenitors, ranging from NS-NS mergers to various hypernova-like scenarios, eventually lead to the formation of a black hole with a debris torus around it, so that the extractable energy is of the same order, 1E+54 ergs, in all cases. MHD conversion of gravitational into kinetic and radiation energy can significantly increase the probability of observing large photon fluxes, although significant collimation may achieve the same effect with neutrino annihilation in short bursts. The lifetime of the debris torus is dictated by a variety of physical processes, such as viscous accretion and various instabilities; these mechanisms dominate at different stages in the evolution of the torus and provide for a range of gamma-ray burst lifetimes.
Meszaros Peter
Rees Martin J.
Wijers Ralph A. M. J.
No associations
LandOfFree
Energetics and beaming of gamma-ray burst triggers does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Energetics and beaming of gamma-ray burst triggers, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Energetics and beaming of gamma-ray burst triggers will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-389253