A few months ago I talked about Astronomers seeing the gas cloud known as G2 passing the central black hole of the Milky Way, called Sagittarius A*, and how we had hoped to watch the black hole destroy it in order to learn about the behaviour of supermassive black holes. As we all sat and watched the passage of the cloud over the course of a few months, we were surprised to find that the cloud remained intact and passed straight by Sag A*. When we last checked in, the leading theory was that the ‘cloud’ actually was a dense...
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...
Quasars are Galaxies with incredibly massive Black Holes at their centre. These Black Holes are fuelled by a swirling disc of material that can be ejected in a long jet along their axis of rotation, all due to the conservation of angular momentum. This accretion disc can be so hot that it causes the central region of the Galaxy to shine more brightly than the entire Galaxy of stars surrounding it. A Belgian team using the Very Large Telescope (VLT) studied a population of 93 Quasars spread over Billions of Light-Years, and noticed that the rotation axes of the Quasars...
