Circumbinary discs around merging stellar-mass black holes

Understand

A circumbinary disc around a pair of merging stellar-mass black holes may be shocked and heated during the recoil of the merged hole, causing a near-simultaneous electromagnetic counterpart to the gravitational wave event.

• The shocks occur around the recoil radius, where the disc orbital velocity is equal to the recoil velocity.
• The amount of mass present near this radius at the time of the merger is critical in determining how much radiation is released.
• We explore the evolution of a circumbinary disc in two limits.