Missing black holes in brightest cluster galaxies as evidence for the occurrence of superkicks in nature

Black-hole kicks are powerful. I mean, really powerful. They can even eject supermassive black holes from the heavier galaxies in our Universe. And then these galaxies are left “empty”.

D. Gerosa, A. Sesana.
Monthly Notices of the Royal Astronomical Society 446 (2015) 38-55. arXiv:1405.2072 [astro-ph.GA].