A radio telescope in Canada has proved its mettle in finding many new examples of fast radio bursts (FRBs) — giving astronomers one of their best shots yet at unraveling the mystery of these cosmic flashes.
“Look! We see FRBs,” Deborah Good, an astronomer at the University of British Columbia in Vancouver, Canada, told a meeting of the American Astronomical Society in Seattle, Washington, on 7 January.
Good reported the first results from the Canadian Hydrogen Intensity Mapping Experiment (CHIME), a telescope that was originally designed to explore the early Universe but has turned out to be ideal for detecting FRBs. First spotted in 20071, FRBs are one of the most intriguing mysteries in astrophysics. They appear all over the sky, and astronomers aren't sure what causes them.
In early testing during July and August, before it began full operations, CHIME spotted 13 FRBs. Prior to this, astronomers had between 50 and 60 examples.
The more FRBs that astronomers find, the greater the chance they can start to pin down their origin. "If we had 1,000 examples, we would be able to say many more things about what FRBs are like," Good said.
Rarest of the rare
CHIME also detected only the second known FRB that repeats, meaning that the radio flashes re-appear at the same point in the sky. It saw the repeater pop up at least five separate times, the first on 14 August, Good said. "We're very excited," she told the meeting.
The only other known repeating FRB is one that first appeared in 20122. It seems to originate in a galaxy some 2.5 billion light-years from Earth3. Finding a second repeater confirms that the first was not some kind of freak event.
CHIME has also detected the lowest-frequency FRB known so far, Good said. It appeared at wavelengths of 400 megahertz, breaking the previous record of 700 megahertz. Previous hunts with other telescopes had not found any FRBs at these lower wavelengths.
Studying lower-frequency FRBs, and the way in which their radiation is scattered on the way to Earth, can reveal more about the environment in which the bursts were born. This includes whether there is a lot of turbulent gas such as in a star-forming region.
The CHIME observatory is located outside Penticton, British Columbia. It consists of four 100-metre-long, semi-cylindrical antennas that look like a half-pipe for snowboarding. The facility operates around the clock and scans the entire northern sky each day — giving it an excellent shot at catching transient FRBs. The bounty of detections came when the instrument was not yet at its full sensitivity, which suggests that it could eventually spot as many as dozens of FRBs each day.
Good said the findings will appear in Nature on 9 January.
Additional reporting by Elizabeth Gibney.