Massive gaseous discs around SMBH binaries: Binary decay and tidal disruptions

¹ Departamento de Astronomía y Astrofísica, Pontificia Universidad Católica de Chile, Chile
² Max-Planck-Institut für Gravitationsphysik (Albert Einstein Institute), Am Mühlenberg 1, 14476 Potsdam, Germany

^a e-mail: jcuadra@astro.puc.cl

Abstract

We investigate the evolution of black hole binaries embedded within geometrically thin gas discs. Our results imply that such discs can produce black hole mergers for relatively low-mass binaries, and that a significant population of eccentric binaries might exist at separations of a few 0.01 pc. These binaries may be detectable due to the time-variable accretion on to the black holes. If the disc fragments, then the newly-born stars will continue driving the binary to its coalescence, although at a slower rate. Interestingly, our preliminary analysis shows that these stars will be disrupted at a rate of ∼10⁻⁴–2 · 10⁻⁵ events per year per system.