In a first, scientists link fast radio bursts to gravitational waves

Though they were predicted in Einstein's theory of general relativity, they are not fully understood and were only recently first detected by the Laser Interferometer Gravitational-Wave Observatory (LIGO) and the Virgo detector.

The team of scientists made up of astronomers from the University of Western Australia (UWA), Curtin University, and the University of Nevada, Las Vegas (UNLV) discovered an FRB that occurred only two and a half hours after a neutron star merger. They published their findings in a paper published in the journal Nature.

Alexandra Moroianu, the lead author of the study, said in a press statement that the possible link between the two events is "extremely exciting" and that it could "unravel some of the mystery surrounding these fast radio bursts, such as why repeating and non-repeating bursts exhibit different properties."

Shedding new light on cosmic phenomena

The researchers behind the new discovery do caution that the association could merely be a coincidence and that follow-up observations are required to better understand whether a link exists at all.

They did, however, hypothesize that two merging neutron stars, which are among the densest objects in the known universe, could create one massive neutron star that spins incredibly quickly before collapsing into a black hole. As black holes cannot have magnetic fields, this process could see the magnetic fields of the merging neutron stars suddenly vanish, causing an FRB to travel into space.

If the correlation is confirmed, it will provide new insight into the properties of neutron stars and how they interact during cataclysmic mergers, as well as the mysterious phenomena known as FRBs.

Study abstract:

Fast radio bursts (FRBs) are bright millisecond-duration radio bursts at cosmological distances. While young magnetars are the leading source candidate, recent observations suggest that there may be multiple FRB progenitor classes. Here we investigate a potential coincidence between a binary neutron star merger event, GW190425, and a bright, non-repeating FRB event, FRB 20190425A. The FRB is located within the gravitational wave sky localization area, occurred 2.5 h after the gravitational wave event and has a dispersion measure consistent with the distance inferred from gravitational wave parameter estimation. The chance probability of a coincidence between unrelated FRB and gravitational wave events in the searched databases is estimated to be 0.0052 (2.8σ). This potential association is consistent with the theory that the binary neutron star merger left behind a supramassive, highly magnetized compact object, which collapsed to form a black hole after losing angular momentum due to spindown and produced an FRB by ejecting the magnetosphere.