COMMENT

Having a supermassive black hole at their centre seems to be something that all but the smallest, puniest galaxies do. It may even be the case that the black holes form first, way back when the Universe was just a few hundred million years old, leaving the rest of a galaxy to coalesce around these seeds.

What is surprising is how active these hidden black holes are. Despite their fearsome reputation, most black holes sit quietly in the centre of their host systems. There was a lot of excitement a few years ago when it seemed like the Milky Way’s black hole would consume a cloud of gas which had the same mass of Jupiter – barely a snack on a cosmic scale.

The black holes in these galaxies have begun a much larger meal, and now we know what they’re up to they will be objects of great interest. CHRIS LINTOTT copresents The Sky at Night