We study the progenitor dependence of the black hole formation and its associated neutrino signals from the gravitational collapse of non-rotating massive stars, following the preceding study on the single progenitor model in Sumiyoshi et al. (2007). We aim to clarify whether the dynamical evolution toward the black hole formation occurs in the same manner for different progenitors and to examine whether the characteristic of neutrino bursts is general having the short duration and the rapidly increasing average energies. We perform the numerical simulations by general relativistic neutrino-radiation hydrodynamics to follow the dynamical evolution from the collapse of pre-supernova models of 40Msun and 50Msun toward the black hole formation via contracting proto-neutron stars. For the three progenitor models studied in this paper, we found that the black hole formation occurs in ~0.4-1.5 s after core bounce through the increase of proto-neutron star mass together with the short and energetic neutrino burst. We found that density profile of progenitor is important to determine the accretion rate onto the proto-neutron star and, therefore, the duration of neutrino burst. We compare the neutrino bursts of black hole forming events from different progenitors and discuss whether we can probe clearly the progenitor and/or the dense matter.
تحميل البحث