The large stationary radio telescope CHIME, the Canadian Hydrogen Intensity Mapping Experiment, has detected 535 fast radio bursts between 2018 and 2019, during its first year of operation. West Virginia University engineer Kevin Bandura explained FRBs are a key to understanding the universe a little bit more.
“Despite not knowing what is causing the FRBs, we can learn more about the universe through them and what is between the FRBs and us,” Bandura, an assistant professor in the Lane Department of Computer and Electrical Engineering at the Benjamin M. Statler College of Engineering and Mineral Resources, said.
FRBs are among the brightest sources ever seen in the sky, but their origin remains a mystery to scientists. The intense flashes of energy blaze for only a millisecond and then disappear without a trace. Bandura has been collaborating on this project since 2012.
Since the first FRB was discovered in 2007, radio astronomers have only caught sight of around 140 bursts in their scopes until recently. With the help of the radio telescope located at the Dominion Radio Astrophysical Observatory, operated by the National Research Council of Canada, in British Columbia, Canada, the telescope has nearly quadrupled the number of FRB discovered to date.
Pranav Sanghavi, a graduate research assistant that has been working alongside Bandura, said in the almost 15-year history of the field, scientists can now learn about FRBs as a population.
“We can now study the trends, patterns, distributions and how similar or different FRBs are from each other,” Sanghavi said. “For example, we were able to distinguish an FRBs fingerprint. We observe four main types and sources we see to repeat have different fingerprints than the ones that do not.”
CHIME will be able to detect FRBs quicker as better understanding of the instrument and cleverer techniques to process data improves.
“The number of events detected will still be constrained by the inherent sensitivity of the instrument itself,” Sanghavi said. “However, an acute knowledge of FRBs as a population can certainly inform researchers designing instruments and surveys to fine tune their radio telescopes so that they can detect as many FRBs as they physically can.”
When the scientists mapped the location of the recorded FRBs, they found the bursts were evenly distributed in space, seeming to arise from any and all parts of the sky. From the FRBs that CHIME was able to detect, the scientists calculated that bright fast radio bursts occur at a rate of about 800 per day across the entire sky, which is the most precise estimate of FRBs overall rate to date.
“This is an enormous number, a common event in the sky,” Sanghavi said. “These bright events that can thus be used as probes of the universe. Originating from far away galaxies these signals can tell us a lot about what is between its source and us. We were able to correlate FRBs in our catalog with the Large Scale Structure of the universe. Additionally, further studies into the mechanisms that may create FRBs can point to some potentially exciting physics.”
For each FRB that CHIME detects, scientists measure its dispersion. From this they found that most bursts likely originated from far-off sources within distant galaxies. The fact that the bursts were bright enough to be detected by CHIME suggests that they must have been produced by extremely energetic sources. As the telescope detects more FRBs, scientists hope to pin down exactly what kind of exotic phenomena could generate such ultrabright, ultrafast signals. Scientists plan to use the bursts to map the distribution of gas throughout the universe.
This research was supported by various institutions including the Canada Foundation for Innovation, the Dunlap Institute for Astronomy and Astrophysics at the University of Toronto, the Canadian Institute for Advanced Research, McGill University and the McGill Space Institute via the Trottier Family Foundation, and the University of British Columbia.