We’re listening CSIRO

A strange flash of radio waves that was recently detected in space has now been traced to its home galaxy – and appears to originate from relatively nearby.

Fast radio bursts (FRBs) are blasts of radio waves that last for only a few milliseconds but can contain as much energy as our sun puts out in decades. Over 50 have been spotted in space since they were first discovered in 2007, however we still don’t know what causes them.

Most detected bursts have been billions of light years away, making them hard to study. But Ryan Shannon at Swinburne University of Technology in Australia and his colleagues recently found one called FRB 171020 that occurred unusually close to Earth.


In the neighbourhood

FRB 171020 was spotted by the Australian Square Kilometre Array Pathfinder telescope in Western Australia. The researchers could tell from its radio wave characteristics that it originated only a hundred or so million light years away.

Elizabeth Mahony at Australia’s national science institute, CSIRO, and her colleagues have now determined that it most likely came from a galaxy called ESO 601-G036 located 120 million light years from Earth.

The galaxy has a similar size, star formation rate, and oxygen abundance to the only other galaxy in which an FRB has been confidently pinpointed, located 2.4 billion light years away in the constellation Auriga.

However, ESO 601-G036 doesn’t emit the same continuous stream of low-level radio emissions as the Auriga galaxy. This contradicts previous suggestions that FRBs can only form in galaxies with these background emissions.

Mahony’s team is now focusing its telescopes on ESO 601-G036 to confirm that it can indeed produce FRBs. If they spot another one, they may be able to pinpoint exactly which part of the galaxy it comes from. “Then we might actually be able to solve the mystery of what causes these fast radio bursts,” she says.

Some people believe the bursts are messages from aliens, but Mahony says they’re more likely to be products of astrophysical events, like the formation of new neutron stars.

Reference: arxiv.org/abs/1810.04354v1