Analytic study of mass segregation around a massive black hole
Astrophysics of Galaxies
2011-02-11 v2 Solar and Stellar Astrophysics
Abstract
We analyze the distribution of stars of arbitrary mass function xi(m) around a massive black hole (MBH). Unless xi is strongly dominated by light stars, the steady-state distribution function approaches a power-law in specific energy x=-E/(m*sigma^2)<x_max with index p=m/4M_0, where E is the energy, sigma is the typical velocity dispersion of unbound stars, and M_0 is the mass averaged over m*xi*x_{max}^p. For light-dominated xi, p can grow as large as 3/2 - much steeper than previously thought. A simple prescription for the stellar density profile around MBHs is provided. We illustrate our results by applying them to stars around the MBH in the Milky Way.
Cite
@article{arxiv.0901.4343,
title = {Analytic study of mass segregation around a massive black hole},
author = {Uri Keshet and Clovis Hopman and Tal Alexander},
journal= {arXiv preprint arXiv:0901.4343},
year = {2011}
}
Comments
Revised version published in Astrophys. J. Lett