Fossil Gas and the Electromagnetic Precursor of Supermassive Binary Black Hole Mergers

Details Fossil Gas and the Electromagnetic Precursor of Supermassive Binary Black Hole Mergers Fossil Gas and the Electromagnetic Precursor of Supermassive Binary Black Hole Mergers

2009-06-04

arxiv.org/abs/0906.0825v1

Astronomy and Astrophysics

Astrophysics

High Energy Astrophysical Phenomena

11 pages, 6 figures, submitted to MNRAS

Scientific paper

Using a one-dimensional height integrated model, we calculate the evolution of an unequal mass binary black hole with a coplanar gas disk that contains a gap due to the presence of the secondary black hole. Viscous evolution of the outer circumbinary disk initially hardens the binary, while the inner disk drains onto the primary (central) black hole. As long as the inner disk remains cool and thin at low $\dot{M}_{\rm ext}$ (rather than becoming hot and geometrically thick), the mass of the inner disk reaches an asymptotic mass typically $\sim 10^{-3}-10^{-4}\Msun$. Once the semimajor axis shrinks below a critical value, angular momentum losses from gravitational waves dominate over viscous transport in hardening the binary. The inner disk then no longer responds viscously to the inspiraling black holes. Instead, tidal interactions with the secondary rapidly drive the inner disk into the primary. Tidal and viscous dissipation in the inner disk lead to a late time brightening in luminosity $L\propto t_{\rm minus}^{5/4}$, where $t_{\rm minus}$ is the time prior to the final merger. This late time brightening peaks $\sim 1$ day prior to the final merger at $\sim 0.1 L_{\rm Edd}$. This behavior is relatively robust because of self regulation in the coupled viscous-gravitational evolution of such binary systems. It constitutes a unique electromagnetic signature of a binary supermassive black hole merger and may allow the host galaxy to be identified if used in conjunction with the Laser Interferometric Space Antenna (LISA) localization.

Affiliated with

Also associated with

No associations

Rating

Fossil Gas and the Electromagnetic Precursor of Supermassive Binary Black Hole Mergers 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 Fossil Gas and the Electromagnetic Precursor of Supermassive Binary Black Hole Mergers, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Fossil Gas and the Electromagnetic Precursor of Supermassive Binary Black Hole Mergers will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-494138