Researchers have announced the detection of a new fast radio burst (FRB), a mysterious and very powerful astronomical event. These flashes of radio waves pack the energy released by the Sun over several days into a fraction of a second. The new one is the farthest and most powerful ever detected, and also comes from a completely unexpected place.
A lot of FRBs have been flashes in the pan, happening once and then never again. Others are seen repeating. Researchers have been able to track events in both camps and most of them come from isolated galaxies. But not this one. This comes from a group of galaxies that are in the process of merging.
When the Australian Square Kilometer Array Pathfinder (ASKAP) radio telescope picked up the signal of FRB 20220610A, astronomers knew they had something special on their hands. It was four times more energetic than other FRBs. Follow-up with the European Southern Observatory's Very Large Telescope suggested it came from something really far away. But only thanks to Hubble could they see the merging group of galaxies that existed when the universe was 5 billion years old.
"It required Hubble's keen sharpness and sensitivity to pinpoint exactly where the FRB came from," lead author Alexa Gordon, of Northwestern University, said in a statement. "Without Hubble's imaging, it would still remain a mystery as to whether this was originating from one monolithic galaxy or from some type of interacting system. It's these types of environments – these weird ones – that are driving us toward better understanding the mystery of FRBs."
Previous FRBs have been linked to magnetars, neutron stars with an incredible magnetic field, interacting with other objects. But this profile doesn’t fit all cases. There might be multiple ways for FRBs to form, or we might be missing a unifying characteristic. The environment where this one comes from is certainly peculiar – a galaxy interacting with at least another six.
"We are ultimately trying to answer the questions: What causes them? What are their progenitors and what are their origins? The Hubble observations provide a spectacular view of the surprising types of environments that give rise to these mysterious events," added co-investigator Wen-fai Fong, also of Northwestern University.
FRBs have only been studied for less than two decades and they are discovered serendipitously. Radio observatories coming online in the coming years will possess much higher precision, which will allow more discoveries of FRBs and greater insight. Hopefully, enough insights to provide some answers.
"We just need to keep finding more of these FRBs, both nearby and far away, and in all these different types of environments," said Gordon.
The results were presented at the 243rd meeting of the American Astronomical Society in New Orleans, Louisiana earlier this month.