A new class of black hole, more than 500 times the mass of the Sun, has been discovered by an international team of astronomers.
The finding in a distant galaxy approximately 290 million light years from Earth is reported today in the journal Nature.
Until now, identified black holes have been either super-massive (several million to several billion times the mass of the Sun) in the centre of galaxies, or about the size of a typical star (between three and 20 Solar masses).
The new discovery is the first solid evidence of a new class of medium-sized black holes. The team, led by astrophysicists at the Centre d’Etude Spatiale des Rayonnements in France, detected the new black hole with the European Space Agency’s XMM-Newton X-ray space telescope.
“While it is widely accepted that stellar mass black holes are created during the death throes of massive stars, it is still unknown how super-massive black holes are formed,” says the lead author of the paper, Dr Sean Farrell, now based at the Department of Physics and Astronomy at the University of Leicester.
He added: “One theory is that super-massive black holes may be formed by the merger of a number of intermediate mass black holes. To ratify such a theory, however, you must first prove the existence of intermediate black holes.
“This is the best detection to date of such long sought after intermediate mass black holes. Such a detection is essential. While it is already known that stellar mass black holes are the remnants of massive stars, the formation mechanisms of supermassive black holes are still unknown.”