A mysterious fast radio burst traces back to a rare cluster of galaxies

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Astronomers have traced one of the most powerful and distant fast radio bursts ever discovered to its unusual cosmic home: a rare “bubble-like” cluster of galaxies. This unexpected discovery could shed more light on the causes of mysterious radio wave explosions, which have puzzled scientists for years.

The intense signal, called FRB 20220610A, was first detected on June 10, 2022, and is… Traveled 8 billion light years to reach Earth. a Light year It is the distance light travels in one year, or 5.88 trillion miles (9.46 trillion km).

Fast radio bursts, or FRBs, are intense, millisecond-long bursts of radio waves of unknown origins. The first FRB was detected in 2007, and since then, hundreds of these fast cosmic flashes have been detected coming from distant points across the universe.

This fast radio burst lasted less than a millisecond, but was four times more energetic than previously detected fast radio bursts. The explosion released the equivalent of our Sun's active emissions over 30 years, according to one report The preliminary study was published in October.

Many fast radio bursts emit extremely bright radio waves that last only a few milliseconds at most before disappearing, making them difficult to observe.

Radio telescopes have proven useful for tracking the paths of fast cosmic flashes, so researchers used the Australian Square Kilometer Radio Telescope, or ASKAP, in Western Australia and the European Southern Observatory's Very Large Telescope in Chile to pinpoint where the mysterious explosion originated. .

The observations led scientists to a giant celestial blob, 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 cluster 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.

The galaxies in the cluster appear to be interacting and may be merging, which may have led to a fast radio burst, according to the researchers.

“Without Hubble's imaging, it would still be a mystery as to whether this fast radio burst originated from a single, homogeneous galaxy or from some sort of cluster,” said lead study author Alexa Gordon, a doctoral student in astronomy at Northwestern University's Weinberg School of the Arts. Interacting systems. And science, in a statement.

“It's these kinds of environments — these exotic environments — that are pushing us toward a better understanding of the mystery of fast radio bursts.”

The galaxy cluster, known as the Compact Cluster, is exceptional and an example of “the densest galactic structures we know of,” said study co-author Wen-Fei Fong, an associate professor of physics and astronomy at Northwestern University and Gordon's advisor.

When galaxies interact, they can trigger explosions of star formation, which can be linked to an explosion, Gordon said.

Fast radio bursts have largely been traced back to isolated galaxies, but astronomers have also found them in globular clusters, which are now a compact cluster, Gordon said.

“We just need to keep finding more of these fast radio bursts, both near and far, and in all these different types of environments,” she said.

Nearly 1,000 fast radio bursts have been detected since their initial discovery about two decades ago, but astronomers are still unsure what causes these bursts.

But many agree that compact objects, such as black holes or neutron stars, and the dense remains of exploded stars, are likely involved. Magnetars, or stars with high magnetismIt may be the root cause of fast radio bursts, according to recent research.

Understanding where fast radio bursts originate can help astronomers determine more about what fundamentally causes them to stream through the universe.

“Although hundreds of FRB events have been detected so far, only a small fraction of them have been mapped to their host galaxies,” study co-author Yuexin Fic Dong said in a statement. “Within this small fraction, only a few came from the dense galactic environment, but none have been seen in such a compact group. So, their birthplace is truly rare.” Dong is a National Science Foundation Research Fellow and a doctoral student in astronomy in Fung's laboratory at Northwestern University.

Further insights into fast radio bursts could also lead to discoveries about the nature of the universe. As the jets travel through space for billions of years, they interact with cosmic matter.

“Radio waves, in particular, are sensitive to any intervening material along the line of sight — from the FRB location to us,” Fung said. “This means that the waves must travel through any cloud of material around the site of the fast radio burst, through the host galaxy, through the universe and finally through the Milky Way. Through the time delay in the FRB signal itself, we can measure the sum of all these contributions.”

Gordon said astronomers expect increasingly sensitive methods for detecting fast radio bursts in the future, which could lead to more of them being detected at greater distances.

“We are ultimately trying to answer the questions: What causes them? What are their ancestors and what are their origins? Hubble's observations provide amazing insight into the amazing types of environments that lead to these mysterious events,” said Fong.