Toronto: In a first, astronomers have detected repeating short bursts of radio waves from an enigmatic source that is likely located well beyond the edge of our Milky Way galaxy.
The findings indicate that these “fast radio bursts” come from an extremely powerful object which occasionally produces multiple bursts in under a minute.
Prior to this discovery, reported in the journal Nature, all previously detected fast radio bursts (FRBs) have appeared to be one-off events.
Because of that, most theories about the origin of these mysterious pulses have involved cataclysmic incidents that destroy their source — a star exploding in a supernova, for example, or a neutron star collapsing into a black hole.
The new finding, however, shows that at least some FRBs have other origins.
FRBs, which last just a few thousandths of a second, have puzzled scientists since they were first reported nearly a decade ago. Despite extensive follow-up efforts, astronomers until now have searched in vain for repeat bursts.
The new findings are based on observations performed with the Arecibo radio telescope in Puerto Rico – the world’s largest radio telescope – last year.
The new data showed a total of 10 new bursts with properties consistent with those of an FRB detected in 2012.
The repeat signals were surprising – and “very exciting,” said researcher Paul Scholz from McGill University in Montreal, Canada.
“I knew immediately that the discovery would be extremely important in the study of FRBs,” Scholz noted.
The finding suggests that these bursts must have come from a very exotic object, such as a rotating neutron star having unprecedented power that enables the emission of extremely bright pulses, the researchers said.
It is also possible that the finding represents the first discovery of a sub-class of the cosmic fast-radio-burst population.
“Not only did these bursts repeat, but their brightness and spectra also differ from those of other FRBs,” said study first author Laura Spitler, post-doctoral researcher at Max Planck Institute for Radio Astronomy in Bonn, Germany.
Scientists believe that these and other radio bursts originate from distant galaxies.
In future research, the team hopes to identify the galaxy where the radio bursts originated.