SUPER-CRITICAL GROWTH OF MASSIVE BLACK HOLES FROM STELLAR-MASS SEEDS

Abstract

We consider super-critical accretion with angular momentum onto stellar-mass\nblack holes as a possible mechanism for growing billion-solar-mass holes from\nlight seeds at early times. We use the radiatively-inefficient "slim disk"\nsolution -- advective, optically thick flows that generalize the standard\ngeometrically thin disk model -- to show how mildly super-Eddington\nintermittent accretion may significantly ease the problem of assembling the\nfirst massive black holes when the Universe was less than 0.8 Gyr old. Because\nof the low radiative efficiencies of slim disks around non-rotating as well as\nrapidly rotating holes, the mass e-folding timescale in this regime is nearly\nindependent of the spin parameter. The conditions that may lead to\nsuper-critical growth in the early Universe are briefly discussed.\n