[SEMINARI] Relativistic collapse and explosion of rotating supermassive stars with thermonuclear effects

[Enric Marco]

Title: Relativistic collapse and explosion of rotating supermassive
stars with thermonuclear effects

by: Pedro Montero

From: Max-Planck-Institut für Astrophysik, Garching, Alemanya

Where: Seminari del departament d'Astronomia i Astrofísica

Date: Dijous 28 juny 2012

Hour: 15:00 h

http://celeste.uv.es/daa/seminari.php.UTF8?id=1058

Resum

We present results of general relativistic simulations of collapsing
supermassive stars with and without rotation using the two-dimensional
general relativistic numerical code Nada, which solves the Einstein
equations written in the BSSN formalism and the general relativistic
hydrodynamics equations with high resolution shock capturing schemes.
These numerical simulations use an equation of state which includes
effects of gas pressure, and in a tabulated form those associated with
radiation and the electron-positron pairs. We also take into account
the effect of thermonuclear energy released by hydrogen and helium
burning. We find that objects with a mass of 5x10^{5} solar mass and
an initial metallicity greater than Z_{CNO}~0.007 do explode if
non-rotating, while the threshold metallicity for an explosion is
reduced to Z_{CNO}~0.001 for objects uniformly rotating. The critical
initial metallicity for a thermonuclear explosion increases for stars
with mass ~10^{6} solar mass. For those stars that do not explode we
follow the evolution beyond the phase of black hole formation. We
compute the neutrino energy loss rates due to several processes that
may be relevant during the gravitational collapse of these objects.
The peak luminosities of neutrinos and antineutrinos of all flavors
for models collapsing to a BH are ~10^{55} erg/s. The total radiated
energy in neutrinos varies between ~10^{56} ergs for models collapsing
to a BH, and ~10^{45}-10^{46} ergs for models exploding.
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/------------------------------------\
Dr. Enric Marco
Departament d'Astronomia i Astrofísica
Facultat de Física
Universitat de València
C/  Dr. Moliner, 50
46100 Burjassot, Spain
Phone: (34)-96-354-3069
Fax:(34)-96-354-3084
enric.marco en uv.es
www.uv.es/marco
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