General Relativistic simulations of collapsing supermassive stars

P. J. Montero, H.-T. Janka, E. Mueller, B. Mueller

There is plenty of evidence confirming the presence of supermassive black holes (SMBHs) in the centre of most galaxies, however their formation mechanism is still
uncertain. Major routes to form a SMBH suggest that they may form either from smaller seeds and grow via accretion or mergers, or that instead, single supermmassive stars form and then undergo a gravitational collapse leading to the formation of SMBHs.
We present results of general relativistic simulations of collapsing supermassive stars using the two-dimensional general relativistic numerical code "Nada", that solves the Einstein equations written in the BSSN formalism and the general relativistic hydrodynamic equations with high resolution shock capturing schemes. Such numerical simulations use a tabulated equation of state which includes effects of radiation and gas pressure, and those associated with the electron-positron pair creation. Furthermore, we will also compute the neutrino energy loss rates due to several mechanisms that may be relevant during the gravitational collapse of these objects.