Relativistic encounters in dense stellar systems
Abstract
Two coalescing black holes (BHs) represent a conspicuous source of gravitational waves (GWs). The merger involves 17 parameters in the general case of Kerr BHs, so that a successful identification and parameter extraction of the information encoded in the waves will provide us with a detailed description of the physics of BHs. A search based on matchedfiltering for characterization and parameter extraction requires the development of some 10^{15} waveforms. If a third additional BH perturbed the system, the waveforms would not be applicable, and we would need to increase the number of templates required for a valid detection. In this paper, we calculate the probability that more than two BHs interact in the regime of strong relativity in a dense stellar cluster. We determine the physical properties necessary in a stellar system for three BHs to have a close encounter in this regime and also for an existing binary of two BHs to have a strong interaction with a third hole. In both cases the event rate is negligible. While dense stellar systems such as galactic nuclei, globular clusters and nuclear stellar clusters are the breeding grounds for the sources of GWs that groundbased detectors like Advanced LIGO and Advanced VIRGO will be exploring, the analysis of the waveforms in full general relativity needs only to evaluate the twobody problem. This reduces the number of templates of waveforms to create by orders of magnitude.
 Publication:

Monthly Notices of the Royal Astronomical Society
 Pub Date:
 March 2011
 DOI:
 10.1111/j.13652966.2010.17925.x
 arXiv:
 arXiv:1009.1870
 Bibcode:
 2011MNRAS.412..551A
 Keywords:

 black hole physics;
 gravitational waves;
 globular clusters: general;
 galaxies: kinematics and dynamics;
 Astrophysics  Cosmology and Nongalactic Astrophysics;
 Astrophysics  Astrophysics of Galaxies;
 General Relativity and Quantum Cosmology
 EPrint:
 A small note of 5 pages, accepted for publication MNRAS after minor modifications