Collapse of rotating very massive stellar core to a black hole and a disk

Abstract

Recent studies of modeling a progenitor of long gamma-ray bursts (LGRBs) suggest that progenitors of LGRBs might have a core with higher entropy than that of ordinary presupernove. Based on the above suggestion, we performed fully general relativistic, two-dimensional simulations of collapse of higher entropy core to a black hole and an accretion disk taking account of important microphysics. The initial core is simply modeled by a equilibrium configuration with constant entropy and electron fraction. We clarified that the formation dynamics depends even qualitatively on the amount of angular momentum. As a novel feature, we discovered that accretion disks formed after collapse can be convectively unstable.