Astrophysics, abstract
astro-ph/0603324

From: Clovis Hopman [view email]

Date: Mon, 13 Mar 2006 21:02:43 GMT (42kb)

The effect of mass-segregation on gravitational wave sources near massive black holes

Authors: Clovis Hopman, Tal Alexander (Weizmann)

Comments: Submitted to ApJL

Gravitational waves (GWs) from the inspiral of compact remnants (CRs) into massive black holes (MBHs) will be observable to cosmological distances. While a CR spirals in, 2-body scattering by field stars may cause it to fall into the MBH before reaching a short period orbit that would give an observable signal. As a result, only CRs very near (~0.01 pc) the MBH can spiral in successfully. In a multi-mass stellar population, the heaviest objects sink to the center, where they are more likely to slowly spiral into the MBH without being swallowed prematurely. We study how mass-segregation modifies the stellar distribution and the rate of GW events. We find that the inspiral rate per galaxy for white dwarfs is 30 per Gyr, for neutron stars 6 per Gyr, and for stellar black holes (SBHs) 250 per Gyr. The high rate for SBHs is due to their extremely steep density profile, n_{BH}(r)\propto r^{-2}. The GW detection rate will be dominated by SBHs.

http://arxiv.org/abs/astro-ph/0603324