This short-lived radio outburst is known as a fast radio burst (FRB) and scientists have been perplexed by them for years. They appear as fleeting signals from distant universes that nobody can properly explain. Scientists are able to trace the origins of FRBs that pulse numerous times over a span of several months. Finding the source of FRBs that last only a few seconds or even less than a second is even more difficult.
However, an Australian-led team of astronomers pinpointed the source of one FRB. By using the Gemini South telescope in Chile, they have successfully confirmed that this particular FRB, known as FRB 180924, which flashed only once and lasted for a thousandth of a second, comes from a galaxy that is roughly 3.6 billion light-years away from Earth.
“It is especially challenging to pinpoint FRBs that only flash once and are gone,” said Keith Bannister, leader of the research team and a member of Australia’s Commonwealth Science and Industrial Research Organization (CSIRO).
It takes a village to find a fast radio burst
FRB 180924 was detected in September 2018 by the Australian Square Kilometre Array Pathfinder (ASKAP), a radio telescope array in Western Australia. ASKAP’s 36 antennas worked together as a single unit to search for FRBs.
The team calculated the extremely minute amount of time in which light reaches each of ASKAP’s 36 antennas to hone in on the galaxy’s position in the Earth’s sky. “From these tiny time differences – just a fraction of a billionth of a second – we identified the burst’s home galaxy,” said Adam Deller, a member of the research team and an associate professor at Swinburne University of Technology.
The team then investigated the distance of FRB 180924, along with other characteristics to help them pinpoint its location, using the Gemini South telescope of the Gemini Observatory in Chile, along with the W.M. Keck Observatory in Hawaii, and the Very Large Telescope (VLT) of the European Southern Observatory, which is also operated in Chile.
“ASKAP gave us the two-dimensional position in the sky, but the Gemini, Keck and VLT observations locked down the distance, which completes the three-dimensional picture,” said Nicolas Tejos of the Pontifical Catholic University of Valparaiso in Chile, team leader of the Gemini observations.
Tejos further reported that with the help of all the data they’ve gathered, they pinpointed not just the galaxy that hosted FRB 180924, and when the light was released, but also the region in the host galaxy where the FRB originated in. They found that it was located in the “galactic suburbs,” away from the host galaxy’s core. (Related: Astronomers detect the earliest example of a “galactic merger”: The two galaxies spotted crashed together 13 BILLION YEARS ago.)
Researchers are optimistic about future understanding of FRBs
According to the researchers, this breakthrough in figuring out where FRBs come from may be a step toward finally helping scientists understand them. Specifically, Bannister and his team believe that their research will help future studies finally understand exactly what creates FRBs in the first place.
According to Tejos, if researchers act quickly, they can use the momentum that this discovery brings to the world of astronomy not just to “perfect the study of transient phenomena, but perhaps later our perceptions of the universe.”