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Astrophysics, High Energy Astrophysical Phenomena, astro-ph.HE,General Relativity and Quantum Cosmology, gr-qc
Abstract:
The dependence of the final fate of supermassive star (SMS) cores on their
mass and angular momentum is studied with simple modeling. SMS cores in the
hydrogen burning phase encounter the general relativistic instability during
the stellar evolution if the mass is larger than $\sim 3 \times 10^4M_\odot$.
Spherical SMS cores in the helium burning phase encounter the general
relativistic instability prior to the onset of the electron-positron pair
instability if the mass is larger than $\sim 1\times 10^4M_\odot$. For rapidly
rotating SMS cores, these values for the threshold mass are enhanced by up to a
factor of $\sim 5$, and thus, for SMSs with mass smaller than $\sim
10^4M_\odot$ the collapse is triggered by the pair-instability, irrespective of
the rotation. After the onset of the general relativistic instability, SMS
cores in the hydrogen burning phase with reasonable metallicity are likely to
collapse to a black hole irrespective of the degree of rotation, whereas the
SMS cores in the helium burning phase could explode via nuclear burning with no
black hole formation, as previous works demonstrate.
