Ultrafast Outflows from Black Hole Mergers with a Mini-Disk

Kohta Murase, Kazumi Kashiyama, Peter Meszaros, Ian Shoemaker, Nicholas Senno

Published 2016-02-22Version 1

Recently, the direct detection of gravitational waves from black hole (BH) mergers was announced by the Advanced LIGO Collaboration. Multi-messenger counterparts of stellar-mass BH mergers are now of great interest, and it has been suggested that a small disk or celestial body may be involved in the coalescence of two BHs. We consider the fate of a wind powered by an active mini-disk in a short accretion episode onto the merged BH with about 10-100 solar masses, and find that its thermal emission could be seen as a fast optical transient with the duration of hours. We also show that the coasting outflow forms external shocks due to interaction with the interstellar medium, whose synchrotron emission might be detected in the radio band on a time scale of years. Finally, we also discuss a possible jet component and the associated high-energy emission.