ANALYTIC STUDY OF MASS SEGREGATION AROUND A MASSIVE BLACK HOLE Academic Article uri icon

abstract

  • Abstract We analyze the distribution of stars of arbitrary mass function ξ (m) around a massive black hole (MBH). Unless ξ is strongly dominated by light stars, the steady-state distribution function approaches a power law in specific energy x≡–E/mσ 2< x max with index p= m/4M 0, where E is the energy, σ is the typical velocity dispersion of unbound stars, and M 0 is the mass averaged over mξx p max. For light-dominated ξ, 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.

publication date

  • May 1, 2009