Australasian Science: Australia's authority on science since 1938

Exclusive news for subscribers

By Stephen Luntz

Subscribe for complete access to all news articles, columns and features each month.

The full text of this article can be purchased from Informit.

X-Ray Source Explains Black Hole Behaviour

The mass of a very bright X-ray source in the Andromeda galaxy has been calculated to be only around ten solar masses, filling in our knowledge of black hole behaviour.

X-ray space telescopes have allowed us to see the universe in a part of the electro­magnetic spectrum that is largely obscured by the atmosphere, leading to the discovery of ultraluminous X-ray sources in nearby galaxies. Astronomers have debated whether these represent black holes a few times the mass of the sun feeding rapidly, or larger objects dining at a more restrained pace.

Now a Nature paper claims to have settled this question following detailed radio wave and X-ray observations. “We watched a black hole go from nibbling daintily at an appetiser to bingeing on the main course, and then gradually slowing down over dessert,” said Dr Matthew Middleton of Durham University.

Dr James Miller-Jones of the Curtin University node of the International Centre for Radio Astronomy says the dramatic variations in radio waves produced by the black hole are indicative of a smaller object. “As gas falls into a black hole, X-rays are produced and these create pressure. Eventually the pressure from the X-rays becomes so great it stops gas falling in any faster, creating a limit known as the Eddington limit.” Rapid gas collection also produces...

The full text of this article can be purchased from Informit.