Astronomy and Astrophysics – Astrophysics
Scientific paper
2005-09-12
Astronomy and Astrophysics
Astrophysics
23 pages, 15 figures (high resolution available upon request), accepted by Astron. Astrophys. Significantly shortened with res
Scientific paper
10.1051/0004-6361:20054193
(abridged) Three-dimensional hydrodynamic simulations with an Eulerian PPM code are presented for the time-dependent evolution of accretion tori around nonrotating and rotating stellar-mass black holes (BHs), using a pseudo-Newtonian gravitational potential to approximate the effects of general relativity. The initial configurations are assumed to be remnants of binary neutron star (NS) or NS+BH mergers and consist of a 4 solar mass BH with varied spin, girded by a torus with a mass between 0.01 and 0.2 solar masses. The evolution of tori without and with physical shear viscosity is simulated, using a realistic equation of state and following the energy loss and lepton number change due to neutrino emission by a neutrino-trapping scheme. The time-dependent efficiency of converting rest-mass energy to neutrinos is found to reach 10 percent, the efficiency of converting neutrino energy into a pair-photon fireball by neutrino annihilation can reach several percent. The rate of the latter process declines with time much less steeply than the total neutrino luminosity, because the ongoing protonization of the torus ensures a rather stable product of neutrino and antineutrino luminosities. The neutrino emission increases steeply with higher viscosity, larger torus mass, and larger BH spin in corotation with the torus. For rotation rates as expected for post-merger BHs (a > 0.5) and reasonable values of the alpha viscosity (alpha ~ 0.1), the considered tori release sufficient energy in neutrinos to account for the energetics of the well-localized short gamma-ray bursts recently detected by Hete and Swift, if collimation is invoked as predicted by hydrodynamic jet simulations.
Janka H.-Th.
Ruffert Max
Setiawan Sandi
No associations
LandOfFree
Three-dimensional simulations of non-stationary accretion by remnant black holes of compact object mergers 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 Three-dimensional simulations of non-stationary accretion by remnant black holes of compact object mergers, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Three-dimensional simulations of non-stationary accretion by remnant black holes of compact object mergers will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-2275