Spinning up black holes with super-critical accretion flows
High Energy Astrophysical Phenomena
2015-05-27 v1
Abstract
We study the process of spinning up black holes by accretion from slim disks in a wide range of accretion rates. We show that for super-Eddington accretion rates and low values of the viscosity parameter alpha (\lesssim 0.01) the limiting value of the dimensionless spin parameter a_* can reach values higher than a_*=0.9978 inferred by Thorne (1974) in his seminal study. For \mdot=10\mdot_{Edd} and alpha=0.01 spin equilibrium is reached at a_*=0.9994. We show that the equilibrium spin value depends strongly on the assumed value of alpha. We also prove that for high accretion rates the impact of captured radiation on spin evolution is negligible.
Keywords
Cite
@article{arxiv.1102.2456,
title = {Spinning up black holes with super-critical accretion flows},
author = {Aleksander Sadowski and Michal Bursa and Marek Abramowicz and Wlodek Kluzniak and Jean-Pierre Lasota and Rafal Moderski and Mohammadtaher Safarzadeh},
journal= {arXiv preprint arXiv:1102.2456},
year = {2015}
}
Comments
11 pages, 8 figures, submitted to Astronomy & Astrophysics