Prompt Tidal Disruption of Stars as an Electromagnetic Signature of Supermassive Black Hole Coalescence

Abstract

In the last decade, a series of breakthroughs in numerical relativity made it possible to simulate black hole binary coalescence on the computer, in fully dynamical spacetime (Pretorius 2005; Baker et al. 2006; Campanelli et al. 2006). The most important astrophysical result of these new techniques has been a self-consistent calculation of gravitational wave (GW) kicks: the recoil imparted via momentum conservation to a newly merged black hole. The final stages of black hole inspiral and merger are accompanied by anisotropic GW emission, which has been numerically demonstrated to produce typical recoil kicks $\sim\!\!10^{2-3}~{\rm km~s}^{-1}$. The magnitude of the kick depends most sensitively on the initial binary mass ratio and on the spin vectors of the black holes.

N. Stone & A. Loeb The Monthly Notices of the Royal Astronomical Society, Vol. 412, pp. 75–80, 20011