Fresh Science

Galaxies fuel their enormous growth by stopping for gas from space, a Victorian astronomer has found.

Dr Alan Duffy, of The University of Melbourne, has discovered how galaxies grow hundreds of times bigger without a decrease in the gas they use to form stars, an inverse relationship that had previously remained a mystery.

“I could see that the amount of gas, the fuel for forming stars, wasn’t changing even though the galaxies were clearly getting bigger. It was a real mystery,” says Alan, a postdoctoral fellow at The University of Melbourne and International Centre for Radio Astronomy Research

By simulating regions of the universe on powerful supercomputers, Alan was able to watch galaxies form and grow over 10 billion years of cosmic time.  The simulations, created with colleagues in The Netherlands, show that the galaxies are able to pull in new gas from the vast regions of nearly empty space around it, using it up as fast as it falls in.

“Now we know what to look for, we can try and catch these galaxies in the act using radio telescopes – something only possible with the enormous new Australian Square Kilometre Array Pathfinder,” Alan says.

Victoria State Finalist: Alan Duffy, The University of Melbourne