GRBs and Hypernova Explosions of Some Galactic Sources - AstrophysicsReport as inadecuate

GRBs and Hypernova Explosions of Some Galactic Sources - Astrophysics - Download this document for free, or read online. Document in PDF available to download.

Abstract: Knowing the Kerr parameters we can make quantitative calculations of therotational energy of black holes. We show that Nova Sco GRO J1655 - 40, IlLupi 4U 1543 - 47, XTE J1550 - 564 and GS 2023 + 338 are relics of gamma-rayburst GRB and Hypernova explosions. They had more than enough rotationalenergy to power themselves. In fact, they had so much energy that they wouldhave disrupted the accretion disk of the black hole that powered them by thecommunicated rotational energy, so that the energy delivery was self limiting.The most important feature in producing high rotational energy in the binary islow donor secondary star mass.We suggest that V4641 Sgr XTE J1819 - 254 and GRS 1915 + 105 underwent lessenergetic explosions; because of their large donor masses. These explosionswere one or two orders of magnitude lower in energy than that of Nova Sco. CygX - 1 1956 + 350 had an even less energetic explosion, because of an evenlarger donor mass.We find that in the evolution of the soft X-ray transient sources the donorsecondary star is tidally locked with the helium star, which evolved from thegiant, as the hydrogen envelope is stripped off in common envelope evolution.The tidal locking is transferred from the helium star to the black hole intowhich it falls. Depending on the mass of the donor, the black hole can be spunup to the angular momentum necessary to power the GRB and Hypernova explosion.The donor decouples, acting as a passive witness to the explosion which, forthe given angular momentum, then proceeds as in the Woosley Collapsar model.High mass donors which tend to follow from low metallicity give long GRBsbecause their lower energy can be accepted by the central engine.

Author: G. E. Brown, C. -H. Lee, E. Moreno Mendez



Related documents