Hints of intriguing diversity seen in super-energetic 'fast radio bursts'

An artist's impression of a fast radio burst (FRB) reaching Earth, with colors signifying different wavelengths of light.
An artist's impression of a fast radio burst (FRB) reaching Earth, with colors signifying different wavelengths of light. (Image credit: Jingchuan Yu, Beijing Planetarium)

The story of sneaky fast radio bursts (FRBs) may be more complicated than we imagined.

It's tough to figure out the origin stories of FRBs because they're so brief, so bright and appear to come from numerous regions in the sky. Most of these powerful cosmic blasts seem to occur in young galaxies, although that's not always the case.

A new study examined a small population of repeating FRBs, looking at the properties of their light — specifically, its polarization. Polarized light oscillates in the same direction, rather than the relatively random wiggling seen in "normal" light. 

Investigating such polarization can reveal key details about FRBs, study team members said.

Video: Fast radio bursts traced to spiral arms of several galaxies by Hubble
Mysterious 'fast radio bursts' fire rhythmically through the cosmos

"The emission from a FRB traverses an enormous distance before hitting Earth, passing through regions that can put their own particular twist on the radio polarization," officials with the Green Bank Observatory in West Virginia, the home institution of one of the new study's co-authors, said in a statement. 

"For this reason, the study of the polarization of FRBs, and the changes it undergoes until it is detected by our telescopes on Earth, tells us about the environments where they are born and all the space in between," they added.

Study team members found that, in the five repeating FRBs they looked at, key details of polarization depend upon the radio frequency in which it is observed. These properties can also change very quickly in a short time.

This image shows the location of fast radio bursts across the night sky.

This image shows the location of fast radio bursts across the night sky. (Image credit: NRAO Outreach/T. Jarrett (IPAC/Caltech); B. Saxton, NRAO/AUI/NSF)

The rapid changes may happen "if repeating FRB emission passes through a complex environment around the bursting sources," the statement added. For example, the FRB light could be moving through the remnants of a supernova (exploded star), the gas surrounding a rapidly rotating, dense stellar corpse called a pulsar, or superheated gas near huge black holes.

"With these measurements, we start to see the evolutionary trend in FRBs, with more active sources in more complex environments and larger polarization changes being younger explosions," study lead author Yi Feng, a scientist at Zhejiang National Lab in Hangzhou, China, said in the statement.

"These extremely active FRBs could be a distinct population," Feng added.

The new study was published online Thursday (March 17) in the journal Science.

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Elizabeth Howell
Staff Writer, Spaceflight

Elizabeth Howell (she/her), Ph.D., is a staff writer in the spaceflight channel since 2022 covering diversity, education and gaming as well. She was contributing writer for Space.com for 10 years before joining full-time. Elizabeth's reporting includes multiple exclusives with the White House and Office of the Vice-President of the United States, an exclusive conversation with aspiring space tourist (and NSYNC bassist) Lance Bass, speaking several times with the International Space Station, witnessing five human spaceflight launches on two continents, flying parabolic, working inside a spacesuit, and participating in a simulated Mars mission. Her latest book, "Why Am I Taller?", is co-written with astronaut Dave Williams. Elizabeth holds a Ph.D. and M.Sc. in Space Studies from the University of North Dakota, a Bachelor of Journalism from Canada's Carleton University and a Bachelor of History from Canada's Athabasca University. Elizabeth is also a post-secondary instructor in communications and science at several institutions since 2015; her experience includes developing and teaching an astronomy course at Canada's Algonquin College (with Indigenous content as well) to more than 1,000 students since 2020. Elizabeth first got interested in space after watching the movie Apollo 13 in 1996, and still wants to be an astronaut someday. Mastodon: https://qoto.org/@howellspace