**New York** In a surprising discovery, astronomers have observed a black hole producing cold, star-making fuel from hot plasma jets and bubbles.
The researchers found that powerful radio jets from the black hole — which normally suppress star formation — are stimulating the production of cold gas in the galaxy’s extended halo of hot gas.
This newly identified supply of cold, dense gas could eventually fuel future star birth as well as feed the black hole itself, said the study published in the Astrophysical Journal.
The researchers studied a galaxy at the heart of the Phoenix Cluster, an uncommonly crowded collection of galaxies about 5.7 billion light-years from Earth.
The team analysed observations of the Phoenix cluster gathered by the Atacama Large Millimeter Array (ALMA), a collection of 66 large radio telescopes spread over the desert of northern Chile.
The researchers believe that the new findings may help to explain the Phoenix cluster’s exceptional star-producing power.
They may also provide new insight into how supermassive black holes and their host galaxies mutually grow and evolve.
“With ALMA we can see that there’s a direct link between these radio bubbles inflated by the supermassive black hole and the future fuel for galaxy growth,” said study lead author Helen Russell, an astronomer with the University of Cambridge in Britain.
“This gives us new insights into how a black hole can regulate future star birth and how a galaxy can acquire additional material to fuel an active black hole,” Russell said.
What the researchers believe to be happening is that, as jet inflate bubbles of hot gas near the black hole, they drag behind them a wake of slightly cooler gas.
The bubbles eventually detach from the jets and float further out into the galaxy cluster, where each bubble’s trail of gas cools, forming long filaments of extremely cold gas that condense and rain back onto the black hole as fuel for star formation.
“It’s a very new idea that the bubbles and jets can actually influence the distribution of cold gas in any way,” said study co-author Michael McDonald, an astrophysicist at the Massachusetts Institute of Technology in the US.