The strongest known fast radio burst has been traced to a 7-galaxy pileup

NEW ORLEANS — A mind-bogglingly strong spurt of electromagnetic energy has for the first time been traced back to a cluster of seven merging galaxies. The finding could bolster the hypothesis that such mysterious flareups, known as fast radio bursts, originate from bizarre, highly magnetized dead stars called magnetars.

Fast radio bursts, or FRBs, are fleeting explosive events: They last fractions of a second but release as much energy as the sun does in a month. It remains unclear what causes these strange spectacles, first discovered in 2007 (SN: 7/25/14).

“We think they’re caused by some kind of very compact object, like a magnetar,” Alexa Gordon, an astronomer at Northwestern University in Evanston, Ill., said January 9 during a news conference at the American Astronomical Society’s annual meeting. Researchers previously spotted a magnetar in our galaxy producing an FRB, though nobody has shown that all such bursts can be attributed to magnetars (SN: 6/4/20).

Using NASA’s Hubble Space Telescope, Gordon and her colleagues took a closer look at where FRB 20220610A, the most powerful and distant FRB discovered to date, came from. The team was surprised to find a collection of seven galaxies located 11 billion light-years from Earth, all crammed inside a region the size of the Milky Way.

“We expected some kind of monolithic spiral galaxy,” says Northwestern astronomer Wen-fai Fong. “It was kind of a jarring image.”

FRBs have been traced back to all sorts of environments, including lone galaxies and globular clusters (SN: 1/4/17; SN: 2/23/22). But this was the first seen emerging from a seven-galaxy pileup, the team reported at the news conference and in a paper posted in November at arXiv.org.

Such chaotic environments can lead to galaxies swapping gas, dust and other material, triggering the birth of new stars. If a massive star formed under these conditions, its death could have left behind a magnetar, potentially explaining the FRB. The team hopes to use the James Webb Space Telescope to probe the seven-galaxy system in detail to look for evidence of a magnetar.