A mysterious radio signal emanating from a galaxy far, far away has been detected by a telescope in British Columbia. The discovery is significant because it’s only the second time ever a repeating signal has been observed by scientists.
In a paper published in the journal Nature on Wednesday, researchers from several Canadian universities reported how they detected 13 new fast radio bursts (FRBs) using the new Canadian Hydrogen Intensity Mapping Experiment (CHIME) radio telescope located in British Columbia’s Okanagan Valley.
“They’re a new mysterious thing, just recently discovered,” Mark Halpern, a physics and astronomy professor at the University of British Columbia, told CTV Vancouver.
FRBs are short bursts of radio waves originating from far outside of our galaxy, according to a press release about the discovery by McGill University.
Although there are still many questions about what exactly they are and what causes them, scientists believe they could be emanating from a powerful astrophysical phenomena billions of light years away.
There have been more than 60 FRBs observed by researchers to date; however, scientists have only ever recorded one other repeating burst from a single source. That FRB was discovered by the Arecibo radio telescope in Puerto Rico in 2015.
“Until now, there was only one known repeating FRB. Knowing that there is another suggests that there could be more out there,” Ingrid Stairs, a member of the CHIME team and an astrophysicist at UBC, said.
“With more repeaters and more sources available for study, we may be able to understand these cosmic puzzles – where they’re from and what causes them.”
In addition to the second repeater, the researchers were able to shed new light on FRBs because they detected them at a much lower frequency than previously recorded finds. The radio bursts were observed by CHIME at frequencies between 400 megahertz (MHz) and 800 MHz. The majority of previously detected FRBs were found at frequencies near 1400 MHz.
“We now know the sources can produce low-frequency radio waves and those low-frequency waves can escape their environment, and are not too scattered to be detected by the time they reach the Earth,” Tom Landecker, a CHIME team member from the National Research Council, said. “That tells us something about the environments and the sources.”
The second repeating FRB was detected during a pre-commissioning run of the CHIME telescope in the summer of 2018, which means it wasn’t even running at its full capacity.
“We’re very excited to see what CHIME can do when it’s running at full capacity,” Deborah Good, a PhD student in physics and astronomy at UBC, said.
The telescope consists of four adjacent cylindrical reflectors and 256 dual-polarization antennas, which receive radiation from a large swatch of sky. To search for FRBs, the telescope will continuously scan the sky for 24 hours a day, seven days a week.
“With CHIME mapping the entire northern hemisphere every day, we’re bound to find more repeaters over time,” Stairs said.
Researchers believe there could be thousands of radio signals travelling to Earth each day. Now that the CHIME telescope has proven it’s capable of detecting these short bursts of energy, astronomers said they’re optimistic they will be able to learn more about these puzzling cosmic radio signals.
“Knowing where they are will enable scientists to point their telescopes at them, creating an opportunity to study these mysterious signals in detail,” Stairs said.
There are a number of theories about what’s causing FRBs, including the possibility that a neutron star is releasing powerful signals after it exploded or even, albeit held by only a small minority, that they’re signals from an alien civilization.