Wandering Supermassive Black Holes Whizzing Through the Universe

An image from the ROMULUS computer simulation showing an intermediate mass galaxy, its bright central region with its supermassive black hole, and the locations (and velocities) of “wandering” supermassive black holes (those not confined to the nucleus; the 10kpc marker corresponds to a distance of about 31 thousand light-years). Simulations have studied the evolution and abundances of wandering supermassive black holes; in the early universe they contain most of the mass that is in black holes. Credit: Ricarte et al, 2021

Every massive galaxy is believed to host a supermassive black hole (SMBH) at its center. Its mass is correlated with the …