2024-01-10 18:42:00
(CNN) — 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 through 8 billion light-years to get to 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 a 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.
An unusual galactic group
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.
“Without the Hubble images, it would remain a mystery whether this FRB originated in a monolithic galaxy or in some type of interacting system,” Alexa Gordon, lead author of the study and doctoral student in astronomy at the Faculty of Astronomy, said in a statement. of Arts and Sciences at Northwestern University.
“It’s these kinds of environments—these strange ones—that push us toward a better understanding of the mystery of FRBs.”
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 and Gordon’s advisor. .
As galaxies interact, they could trigger bursts of star formation, which could be related to the burst, Gordon said.
Fast radio bursts have been detected primarily in isolated galaxies, but astronomers have also found them in globular clusters and, now, in a compact group, explains Gordon.
“We need to continue to find more FRBs of this type, both near and far, and in all these types of environments,” he said.
Investigation of the origins of fast radio bursts
Nearly 1,000 fast radio bursts have been detected since their initial discovery about two decades ago, but astronomers remain unclear what causes them.
However, many agree that compact objects, such as black holes or neutron stars, are probably the dense remains of stars that have exploded. The magnetars, or highly magnetized starsmay be the cause of fast radio bursts, according to recent research.
Understanding the origin of fast radio bursts could help astronomers better determine the underlying cause that launches them across the universe.
“Despite hundreds of FRB events discovered to date, only a fraction of them have been identified with their host galaxies,” study co-author Yuxin Vic Dong said in a statement. “Within that small fraction, only a few came from a 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 researcher and astronomy doctoral student in Fong’s lab at Northwestern.
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.
“Radio waves, in particular, are sensitive to any intervening material along the line of sight, from the FRB location to us,” Fong said. “That means the waves have to travel through any cloud of material around the FRB site, through its host galaxy, through the universe and finally through the Milky Way. Starting with a delay in the FRB signal, we can measure the sum of all these contributions.”
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.
“Ultimately, we are trying to answer the questions: What causes them? Who are their parents and what are their origins? “Hubble observations provide a spectacular view of the surprising types of environments that give rise to these mysterious events,” Fong said.
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