  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.
