Circumbinary Accretion: From Binary Stars to Massive Binary Black Holes

We review recent works on the dynamics of circumbinary accretion, including time variability, angular momentum transfer between disk and binary, secular evolution accreting binaries. These impact stellar binary formation/evolution, planet formation/migration, (super)massive black hole discuss inclined/warped disks connect with observations protoplanetary disks. A special kind accretion involves binaries embedded in big disks, which may contribute to mergers stellar-mass holes AGN Highlights include following: ▪ Circumbinary is highly variable, being modulated at P b (the period) or ∼5 , depending eccentricity e mass ratio q . The inner region can develop coherent eccentric structure, modulate affect physical processes (e.g., migration) taking place disk. Over long timescales, steers toward equal masses, it does not always lead orbital decay. depends parameters ( ) thermodynamic properties gas. misaligned around a low-eccentricity tends evolve coplanarity due viscous dissipation. But when significant, “polar alignment,” plane perpendicular plane. Expected final online publication date for Annual Review Astronomy Astrophysics, Volume 61 August 2023. Please see http://www.annualreviews.org/page/journal/pubdates revised estimates.