Mysterious fast radio bursts ‘light up’ night sky in major discovery

11 Oct 2018

ASKAP antennas with the Milky Way overhead. Image: CSIRO

Researchers in Australia have identified a treasure trove of mysterious fast radio bursts in deep space.

Despite still having no idea what they are, Australian researchers using the Commonwealth Scientific and Industrial Research Organisation (CSIRO) telescope in Western Australia have discovered a record haul of fast radio bursts (FRBs).

The mysterious bursts are believed to involve incredible amounts of energy – the equivalent of what the sun puts out in an 80-year period. In this discovery, the team has nearly doubled the known number of FRBs. Among the haul, the team reported in Nature, were the closest and brightest FRBs ever detected.

The discovery of 20 in this latest survey was bolstered by the use of new technology found in the Australia Square Kilometre Array Pathfinder (ASKAP), which also confirmed that FRBs are coming from the other side of the universe, rather than within our own galactic neighbourhood.

Over the course of billions of years, these bursts travel across the universe to us, but every so often they pass through a cloud of cosmic gas, slowing them ever so slightly. “Eventually, the burst reaches Earth with its spread of wavelengths arriving at the telescope at slightly different times, like swimmers at a finish line,” said the study’s co-author, Dr Jean-Pierre Macquart from the International Centre for Radio Astronomy Research.

“Timing the arrival of the different wavelengths tells us how much material the burst has travelled through on its journey. And, because we’ve shown that fast radio bursts come from far away, we can use them to detect all the missing matter located in the space between galaxies, which is a really exciting discovery.”

Localising the bursts

Speaking of the technology involved, ASKAP engineer Dr Keith Bannister said this latest discovery was down to the telescope dish’s field of view – 100 times larger than the full moon. When multiple dish antennas point at different parts of the sky, this bumps up the field of view even more, to an equivalent of 1,000 times the area of a full moon.

The team will now look to pinpoint the locations in the sky where the FRBs came from. Lead author of the research, Dr Ryan Shannon, explained what this will mean. “We’ll be able to localise the bursts to better than a thousandth of a degree. That’s about the width of a human hair seen 10 metres away, and good enough to tie each burst to a particular galaxy.”

Colm Gorey was a senior journalist with Silicon Republic