Two Supermassive Black Holes are Merging

A vast number of Galaxies in the Universe have a central black hole that is incredibly massive.  The Black Hole at the centre of the Milky Way, dubbed Sag A*, is estimated to have a mass as high as three Million Suns.  We generally can’t see black holes, but when they start to pull in matter from surrounding gas and dust clouds, the material forms a disk around the star.  This accretion disk can heat up to incredible temperatures and emit X-rays and other high energy light, allowing us to see where the black holes are.  Sometimes the light from...