Where to find Electromagnetic Wave Counterparts of stellar-mass binary black hole mergers?

Understand

Multi-messenger astronomy combining Gravitational Wave (GW) and Electromagnetic Wave (EM) observation brings huge impact on physics, astrophysics and cosmology.

• However, the majority of sources to be detected with currently running ground-based GW observatories are binary black hole (BBH) mergers, which are expected disappointedly to have no EM counterparts.
• In this letter, we propose that if the BBH merger happens in a gaseous disk around a supermassive black hole, the merger can be accompanied by a transient radio flare alike a fast radio burst (FRB).
• We argue that the total mass and the effective spin derived from GW detection can be used to distinguish such a source from other channels of BBH mergers.