English

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

Astrophysics 2014-10-13 v1 General Relativity and Quantum Cosmology

Abstract

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.

Keywords

Cite

@article{arxiv.astro-ph/0603324,
  title  = {The effect of mass-segregation on gravitational wave sources near massive black holes},
  author = {Clovis Hopman and Tal Alexander},
  journal= {arXiv preprint arXiv:astro-ph/0603324},
  year   = {2014}
}

Comments

Submitted to ApJL