Astronomers have traced the origin of a powerful and mysterious radio signal
(CNN) — Astronomers have linked one of the most powerful and distant fast radio bursts ever detected to its unusual cosmic origin: a strange group of blob galaxies. An unexpected discovery could shed more light on the causes of mysterious bursts of radio waves that have baffled scientists for years.
The intense signal, named 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 such fast cosmic flares have been detected in distant places 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 an amount of energy equivalent to 30 years’ worth of emissions from our sun, according to initial research published in October.
Many FRBs emit ultra-bright radio waves that last no more than a few milliseconds before disappearing, making them difficult to observe.
Radio telescopes have proven useful in tracking the trajectories of fast cosmic flares, so the researchers used the Australian ASKAP radio telescope in Western Australia and the European Southern Observatory’s Very Large Telescope in Chile. there was an explosion.
The observations led scientists to a giant spot in the sky that 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 discover that the fast radio burst originated from a group of at least seven galaxies so close together that they could all fit inside the Milky Way.
The results were presented Tuesday at the 243rd meeting of the American Astronomical Society in New Orleans.
An unusual group of galaxies
According to the researchers, the galaxies in the group appear to be interacting and may even be in the process of merging, which could cause a fast radio burst.
“Without Hubble images, it would remain a mystery whether this FRB originated in a monolithic galaxy or in some type of interacting system,” said Alexa Gordon, lead author of the study and an astronomy graduate student in the Department of Astronomy. Doctor of Arts and Sciences Statement from Northwestern University.
“It is this strange environment that pushes us to better understand the mystery of the FRB.”
The galactic group, known as a compact group, is exceptional and an example of “the densest galactic-scale structures that we know of,” said study co-author Wen-Fai Fong, an assistant professor of physics and astronomy at Northwestern University and Gordon’s advisor. . .
According to Gordon, interactions between galaxies could cause bursts of star formation that could be associated with the flare.
Fast radio bursts have been detected mostly in isolated galaxies, but astronomers have also detected them in globular clusters and now compact groups, Gordon explains.
“We need to continue to find more FRBs of this type, both near and far, and in all of these types of environments,” he said.
Research on the origin of fast radio bursts
About 1,000 fast radio bursts have been detected since their initial discovery about two decades ago, but astronomers are still unclear what causes them.
However, many agree that compact objects such as black holes or neutron stars are likely dense remnants of exploding stars. Magnetars, or highly magnetized stars, may be responsible for fast radio bursts, according to recent research.
Understanding the origins of fast radio bursts can help astronomers better determine the underlying cause that launches them across the Universe.
“Despite hundreds of FRB events detected to date, only a fraction of them have been identified with host galaxies,” study co-author Yuxin Vic Dong said in a statement. “In this small group, only a few came from the dense galactic environment, but none had ever been seen in such a compact group. Therefore, his birthplace is truly rare.” Dong is a National Science Foundation graduate student and an astronomy graduate student in Fong’s lab at Northwestern University.
Better knowledge of fast radio bursts could also lead to discoveries about the nature of the universe. As bursts travel through space over billions of years, they interact with cosmic material.
“Radio waves in particular are sensitive to any material in the line-of-sight path from the FRB location to us,” Fong said. “This means that the waves must travel through any cloud of material around the FRB site, through its host galaxy, through the Universe and finally through the Milky Way. Starting from the delay of the FRB signal, we can measure the sum of all these contributions.”
Astronomers see more sensitive methods for detecting fast radio bursts in the future, which could lead to detection of more of them at greater distances, Gordon said.
“Ultimately we are trying to answer the questions: What causes them? Who are their parents and what is their origin? “Hubble’s observations provide fascinating insight into the surprising types of environments that give rise to these mysterious events,” Fong said.