Astronomers get new hints at the origins of mysterious Fast Radio Bursts

A dense, highly-magnetized, gas-filled region of space has been associated with the origins of Fast Radio Bursts—bright pulses of energy that appear to Earth-based telescopes as short flashes of radio waves, according to research published Wednesday in the journal Nature.

Scientists have been working to characterize these mysterious radio pulses ever since they were first detected roughly 10 years ago. Only 16 Fast Radio Bursts (FRBs) have ever been detected, the study authors explained, but some believe there could be thousands each day.

“We now know that the energy from this particular burst passed through a dense magnetized field shortly after it formed,” lead author Kiyoshi Masui, an astronomer with the University of British Columbia, said in a statement. The discovery “significantly narrows down the source’s environment and type of event that triggered the burst—and means the source of the pulse likely resides within a star-forming nebula or the remnant of a supernova,” he added.

Masui and his colleagues were able to detect and identify the new FRB through the use of data-mining software he developed alongside Jonathan Sievers of the University of KwaZulu-Natal in Durban, South Africa. The software made it easier for astronomers to search for bursts during an analysis of data collected by radio telescopes, the research team explained.

One of two explanations for the signal’s unique imprint

Within the data, they discovered what co-author and Carnegie Mellon university faculty member Jeffery Peterson called “a very peculiar signal that matched all the known characterizes of a Fast Radio Burst, but with a tantalizing extra element that we simply have never seen before.”

Further analysis revealed that the burst exhibited a corkscrew-like twist called Faraday rotation, which is observed in radio waves that pass through strong magnetic fields. They found that this particular FRB passed through two separate screens (regions of ionized gas) on its way to Earth, and used this information to pinpoint the relative locations of each screen.

The stronger of the two screens was found close to the burst’s source, meaning it is within the source galaxy and likely less than 100,000 light-years away from said source. Furthermore, they concluded that the imprint found on the signal had to come either from a nebula that surrounded the source, or from a galactic center.

“Taken together, these remarkable data reveal more about an FRB than we have ever seen before and give us important constraints on these mysterious events,” Masui said. “We also have an exciting new tool to search through otherwise overwhelming archival data to uncover more examples and get closer to truly understanding their nature.”

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Feature Image: Jingchuan Yu, Beijing Planetarium