When Black Holes Collide
American astronomers have captured a pair of supermassive black holes poised to undergo an extreme
collision. The black holes lurk at the centre of a cluster of galaxies, Abel 400. At the moment the
two black holes in Abel 400 are widely separated, each surrounded by a vast accretion disc of gas
and dust. For this picture, though, I imagined the scenario in several billion years, when the holes
reside in a single disk and are about to collide.