AN international team of astronomers led by Xue-Bing Wu at Peking University discovered a huge and ancient black hole which was powering the brightest object early in the universe. The black hole’s mass is 12 billion times that of the sun, and it lives at the centre of a quasar that pumped out a million billion times the sun’s energy.
The finding was reported in a recent issue of Nature. Wu selected the quasar from the Sloan Digital Sky Survey of over 500 million objects in the northern skies because of its distinctive red colour. It was then followed up for detailed study using three other telescopes. A quasar is an extremely bright cloud of material in the process of being sucked into a black hole. As the material accelerates towards the black hole, it heats up and emits an extraordinary amount of light, which actually pushes away material falling behind it. The team member Fuyan Bian of the Australian National University (ANU) said the discovery challenged theories of how black holes form and grow in the early universe: “Forming such a large black hole so quickly is hard to interpret with current theories. Radiation pressure is thought to limit the growth rate of black holes. However, this black hole at the centre of the quasar gained enormous mass in a short period of time…. Skymapper [a survey of the southern skies currently being run by the ANU] will find more of these exciting objects. Because they are so luminous, we can see further back in time and can use them to explore the early universe.”