Pune telescope helps make major breakthrough

Not much is known about fast radio bursts, which can produce so much energy in so little time

Astronomers of National Centre of Radio Astrophysics (NCRA-TIFR) in Pune and the University of California in the U.S. have used the Giant Metrewave Radio Telescope (GMRT) to map the distribution of atomic hydrogen gas from the host galaxy of a fast radio burst (FRB) for the first time.

Fast radio bursts

Fast radio bursts are extremely bright radio pulses from distant galaxies that last for only a few milliseconds, and though they were first detected fifteen years ago and over a thousand have been found so far, researchers still don't know what kind of astronomical objects can produce so much energy in so little time.

According to the researchers, the exercise has revealed exciting clues about the origin of the burst.

"The GMRT results indicate the FRB host galaxy has undergone a recent merger and that the FRB progenitor is most likely a massive star formed due to this merger event. This is the first case of direct evidence for a recent merger in an FRB host, a major step towards understanding the progenitors of FRBs," Balpreet Kaur, a PhD student at NCRA-TIFR and the lead author of the study, said. "Observations of the gas and stars in the vicinity of FRBs and within their host galaxies are critical to understanding how the bursts were formed," Kaur said, adding that their target FRB (FRB20180916B) produces repeated, very short bursts, and these have been found to arise in the outskirts of a spiral galaxy half a billion light-years away.

Ideal candidate

She said FRB20180916B is thus one of the closest known FRBs, an ideal candidate to study the local burst environment.

Professor Nissim Kanekar, who is co-author in the research, said GMRT was apt for conducting such studies as one can use different combinations of the 30 GMRT antennas to map the atomic hydrogen within the FRB host galaxy in detail as well as to search for hydrogen in nearby companion galaxies.

This is the first case of direct evidence for a recent merger in an FRB host and showcases the ability of the GMRT to identify such mergers via disturbances in the gas distribution, they said.

The authors plan to carry out similar studies of more FRB host galaxies to test whether merger events might be a common trigger for FRB formation.