Astronomers spot supermassive black hole devouring cold gas cloud
London, June 9 (IANS) Marking the first direct evidence to support the theory that black holes feed on clouds of cold gas, astronomers have detected billowy clouds of cold, clumpy gas streaming towards a supermassive black hole at speeds of up to 800,000 miles per hour and feeding into its bottomless well.
Using one of the most powerful telescopes in the world — the Atacama Large Millimeter/submillimeter Array, or ALMA — the team found that the feeding process was “chaotic” and “clumpy”, as opposed to a smooth, simple and clean process that was previously hypothesised.
“It was magical being able to see evidence of these clouds accreting onto the supermassive black hole,” said one of the researchers Timothy Davis from School of Physics and Astronomy, Cardiff University in Britain.
“At that very moment, nature gave us a clear view of this complicated process, allowing us to understand supermassive black holes in a way that has never been possible before,” Davis noted.
The findings were detailed in the journal Nature.
“The data has provided us with a snapshot of what is happening around the black hole at one precise time, so it’s possible that the black hole has an ever bigger appetite and is devouring even more of these cold clouds of gas surrounding it,” Davis said.
Previous models have suggested that the gradual growth of supermassive black holes — a process known as accretion — occurs when surrounding hot gas accumulates smoothly onto the black hole, much like a slow graze.
But the very first observations made by the international team of researchers suggest that in addition to this, supermassive black holes may occasionally quickly gobble up faster-moving cold gas as it comes nearby.
The research team used ALMA to observe a distant galaxy one billion light years away. The galaxy, called Abell 2597, spans some tens of thousands of light years across and is one of the brightest in the universe.
The team were interested in discerning how many stars were being born in the galaxy and therefore went about measuring cold gas – stars are formed when cold gas collapses.
To the team’s surprise, they ended up discovering something quite unexpected at the centre of the galaxy around a supermassive black hole – the shadows of three very cold, clumpy gas clouds.
The three gas clouds were cast against bright jets of material spewing from the black hole, suggesting that these clouds were very close to being consumed by the black hole.