Fast radio bursts (FRBs) are microsecond-millisecond flashes of radio waves that are detectable over extragalactic distances; some FRB sources repeat. Astronomers from the CHIME/FRB Collaboration have now doubled the number of known FRBs and solidified the idea that all FRBs may eventually repeat.
An artist’s impression of FRB 110523 reaching Earth; the colors represent the burst arriving at different radio wavelengths, with long wavelengths (red) arriving seconds after short wavelengths (blue). Image credit: Jingchuan Yu / Beijing Planetarium.
“We can now accurately calculate the probability that two or more bursts coming from similar locations are not just a coincidence,” said Dr. Ziggy Pleunis, a postdoctoral researcher with the Dunlap Institute for Astronomy and Astrophysics at the University of Toronto.
“These new tools were essential for this study, and will also be very useful for similar research going forward.”
“Thanks to radio telescopes like the Canadian Hydrogen Intensity Mapping Experiment (CHIME), the number of detected FRBs has grown from a few tens, to thousands in recent years.”
“This is due to CHIME’s capacity to scan the entire northern sky every day. That’s how CHIME has an edge over other telescopes, when it comes to discovering FRBs.”
In their research, Dr. Pleunis and colleagues found that many repeating FRBs are surprisingly inactive, producing less than one burst per week of observing time.
Many apparently one-off FRBs have simply not yet been observed long enough for a second burst from the source to be detected.
“It is exciting that CHIME/FRB saw multiple flashes from the same locations, as this allows for the detailed investigation of their nature,” said Adaeze Ibik, a Ph.D. student in the Dunlap Institute for Astronomy and Astrophysics at the University of Toronto.
“We were able to hone in on some of these repeating sources and have already identified likely associated galaxies for two of them.”
“This new discovery brings us closer to understanding what FRBs are. While that is exciting in itself, he says there are even further-reaching implications,” Dr. Pleunis said.
“FRBs are likely produced by the leftovers from stellar explosions. By studying repeating FRB sources in detail, we can study the environments that these explosions occur in and understand better the end stages of a star’s life.”
“We can also learn more about the material that’s being expelled before and during the star’s demise, which is then returned to the galaxies that the FRBs live in.”
The results were published in the Astrophysical Journal.
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Bridget C. Andersen et al. 2023. CHIME/FRB Discovery of 25 Repeating Fast Radio Burst Sources. ApJ 947, 83; doi: 10.3847/1538-4357/acc6c1
