Astronomers have traced one of the most powerful and distant fast radio bursts ever detected to its unusual cosmic origin: a strange group of “blob” galaxies. The unexpected discovery could shed more light on the causes of mysterious bursts of radio waves, which have baffled scientists for years.
The intense signal, called FRB 20220610A, was first detected on June 10, 2022 and traveled 8 billion light-years to reach Earth. A light year is the distance light travels in one year, or 5.88 trillion miles (9.46 trillion kilometers).
Fast radio bursts (FRBs) are intense bursts of millisecond radio waves of unknown origin. The first FRB was discovered in 2007, and since then hundreds of these fast cosmic flashes have been detected from distant points in the universe.
This particular fast radio burst lasted less than a millisecond but was four times more energetic than previously detected FRBs. The explosion released the equivalent of our sun’s energy emissions over the course of 30 years, according to an initial study published in October.
Many FRBs emit super-bright radio waves that last at most a few milliseconds before disappearing, making them difficult to observe.
Radio telescopes have proven useful in tracking the trajectories of fast cosmic flashes, so researchers used the Australian Square Kilometer Array Pathfinder, or ASKAP, radio telescope in Western Australia, and the European Southern Observatory’s Very Large Telescope in Chile, to determine where the enigmatic explosion originated.
The observations led scientists to a gigantic skyspot, which was initially thought to be a single irregular galaxy or a group of three interacting galaxies.
Now, astronomers have used images from the Hubble Space Telescope to reveal that the fast radio burst came from a group of at least seven galaxies so close together that they could all fit inside the Milky Way.
The findings were presented Tuesday at the 243rd meeting of the American Astronomical Society in New Orleans.
The galaxies in the group appear to be interacting and could even be in the process of merging, which could have triggered the fast radio burst, according to the researchers.
The galactic group, known as a compact group, is exceptional and an example of the “densest galaxy-scale structures we know of,” said study co-author Wen-fai Fong, an associate professor of physics and astronomy at Northwestern University.
As galaxies interact, they could trigger bursts of star formation, which could be related to the burst, Gordon said.
Nearly 1,000 fast radio bursts have been detected since their initial discovery about two decades ago, but astronomers remain unclear what causes them.
Greater knowledge of fast radio bursts could also lead to revelations about the nature of the universe. As the bursts travel through space for billions of years, they interact with cosmic material.
Astronomers envision increasingly sensitive methods for detecting fast radio bursts in the future, which could lead to discovering more of them at greater distances, Gordon said.