Thousands of hidden black holes could be revealed with new method

13 Apr 2018

Image: Andrey VP/Shutterstock

The universe is often described as silent, but a new way to listen in on the major events that often go unmissed has been developed by a team of researchers.

The past three years have been a gold rush era for astronomy as the confirmation of the detection of gravitational waves – the ripples produced by cataclysmic events in the universe – helped open a new window on interstellar mysteries.

Since then, it has become apparent that the universe we once thought was silent is anything but, and now we are finding ways of filtering out the background hum to find true marvels of astrophysics.

Future Human

In a paper published to the journal Physical Review X by a team of researchers from Monash University in Australia, a new listening method was introduced and it is expected to reveal the presence of thousands of previously hidden black holes by teasing out their faint whoops from a sea of static.

While six confirmed gravitational-wave events have been announced so far by the LIGO and Virgo Collaborations, there are more than 100,000 gravitational-wave events every year that are too faint to detect.

Researchers have spent years trying to find a way to measure the phenomenon through the hum, and now the Monash team can do so, having developed computer simulations of faint black hole signals.

They then collected masses of data until they were convinced that, within this simulated data, there was faint but unambiguous evidence of black hole mergers.

1,000 times more sensitive

Dr Rory Smith of the research team has estimated that the new method is 1,000 times more sensitive than previous simulations thanks to recent improvements in data analysis. It will enable the detection of “what people had spent decades looking for”.

Smith’s colleague, Dr Eric Thrane, added: “Measuring the gravitational-wave background will allow us to study populations of black holes at vast distances.

“Some day, the technique may enable us to see gravitational waves from the Big Bang, hidden behind gravitational waves from black holes and neutron stars.”

Adding to the team’s efforts will be its access to a new A$4m supercomputer called OzStar, to be used by scientists to look for gravitational waves in LIGO data.

Smith added: “OzStar has the potential to make big discoveries in gravitational-wave astronomy.”

Colm Gorey was a senior journalist with Silicon Republic