Astronomy and Astrophysics – Astrophysics
Scientific paper
2007-10-23
Astronomy and Astrophysics
Astrophysics
13 pages, 16 figures, 2 tables, some major revisions, accepted for publication by ApJ
Scientific paper
10.1086/590651
We develop a formalism for studying the dynamics of massive black hole binaries embedded in gravitationally-bound stellar cusps, and study the binary orbital decay by three-body interactions, the impact of stellar slingshots on the density profile of the inner cusp, and the properties of the ejected hypervelocity stars (HVSs). We find that the scattering of bound stars shrinks the binary orbit and increases its eccentricity more effectively than that of unbound ambient stars. Binaries with initial eccentricities e>0.3 and/or unequal-mass companions (M_2/M_1<0.1) can decay by three-body interactions to the gravitational wave emission regime in less than a Hubble time. The stellar cusp is significantly eroded, and cores as shallow as \rho\propto r^-0.7 may develop from a pre-existing singular isothermal density profile. A population of HVSs is ejected in the host galaxy halo, with a total mass ~M_2. We scale our results to the scattering of stars bound to Sgr A*, the massive black hole in the Galactic Center, by an inspiraling companion of intermediate mass. Depending on binary mass ratio, eccentricity, and initial slope of the stellar cusp, a core of radius ~0.1 pc typically forms in 1-10 Myr. On this timescale about 500-2500 HVSs are expelled with speeds sufficiently large to escape the gravitational potential of the Milky Way.
Haardt Francesco
Madau Piero
Sesana Alberto
No associations
LandOfFree
Interaction of massive black hole binaries with their stellar environment: III. Scattering of bound stars does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Interaction of massive black hole binaries with their stellar environment: III. Scattering of bound stars, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Interaction of massive black hole binaries with their stellar environment: III. Scattering of bound stars will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-456340