Year: 2005
Type: article
Abstract: Current simulations of the rate at which stellar-mass compact objects merge with supermassive black holes (called extreme mass ratio in-spirals, or EMRIs) focus on two-body capture by emission of gravitational radiation. The gravitational wave signal of such events will likely involve a significant eccentricity in the sensitivity range of the Laser Interferometer Space Antenna ( LISA ). We show that tidal separation of stellar-mass compact object binaries by supermassive black holes will instead produce events whose eccentricity is nearly zero in the LISA band. Compared to two-body capture events, tidal separations have a high cross section and result in orbits that have a large pericenter and small apocenter. Therefore, the rate of interactions per binary is high, and the resulting systems are very unlikely to be perturbed by other stars into nearly radial plunges. Depending on the fraction of compact objects that are in binaries within a few parsecs of the center, the rate of low-eccentricity LISA events could be comparable to or larger than the rate of high-eccentricity events.
Source: The Astrophysical Journal
DOI: 10.1086/497335
Authors: M. Coleman Miller, Marc Freitag, Douglas P. Hamilton, Vanessa M. Lauburg
Institutions: University of Maryland, College Park, Northwestern University
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W2163900940