Astronomers have discovered the origin of a powerful and mysterious radio signal

(CNN) — Astronomers have discovered the unusual cosmic origins of one of the most powerful and distant fast radio bursts ever detected: a strange group of “blob” galaxies. This unexpected discovery could shed more light on the causes of mysterious bursts of radio waves that have baffled scientists for years.

The intense signal, called FRB 20220610A, was first discovered on June 10, 2022, and traveled 8 billion light years to reach Earth. A light year is the distance that 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 bright 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 identified FRBs. According to a preliminary study published in October, the explosion released emissions equivalent to the energy output of our Sun over the course of 30 years.

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 bright cosmic flashes, so the 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 To where is that mysterious. The explosion occurred.

The observations led scientists to a giant galaxy that was initially thought to be a single irregular galaxy or a cluster 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 that were 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 cluster

The galaxies in the group appear to be interacting and may even be in the process of merging, causing fast radio bursts, according to the researchers.

“Without the Hubble images, it will remain a mystery whether this FRB originated in an intact galaxy or in some type of interacting system,” said Alexa Gordon, lead author of the study and a doctoral student in astronomy in the Faculty of Astronomy. Statement of Arts and Sciences at Northwestern University.

“It is these types of environments – these strange ones – that push us toward a better understanding of the mystery of FRBs.”

The galactic cluster, known as a compact cluster, is extraordinary and “the densest galaxy-scale,” said study co-author Wen-Fai Fong, associate professor of physics and astronomy at Northwestern and Gordon’s advisor. An example of structures that we know about.” …

As galaxies interact, they can trigger a burst of star formation, which could be related to the explosion, Gordon said.

Fast radio bursts have been found primarily in isolated galaxies, but astronomers have also found them in globular clusters and now, in a compact cluster, Gordon explains.

“We need to continue to find more FRBs of this type, near and far, and in all these types of environments,” he said.

Investigation into the origin of intense radio bursts

Nearly 1,000 fast radio bursts have been detected since their initial discovery nearly two decades ago, but astronomers are unclear as to what causes them.

However, many agree that compact objects, such as black holes or neutron stars, are likely the dense remains of exploded stars. Magnetars, or highly magnetized stars, may cause rapid radio bursts, according to recent research.

Understanding the origins of fast radio bursts can help astronomers better determine the underlying cause that launches them into 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. “In that small part, only a few came from dense galaxy environments, but none had ever been seen in such a compact group. Therefore, his birthplace is indeed rare. Dong is a National Science Foundation graduate researcher and doctoral student in astronomy in Fong’s laboratory at Northwestern.

More information about fast radio bursts may also hold revelations about the nature of the universe. As explosions travel through space over billions of years, they interact with cosmic material.

“Radio waves, in particular, are sensitive to any interfering material in our line of sight from the FRB location,” Fong said. “This means that the waves must travel through any clouds of material around the FRB site, through its host galaxy, through the universe, and finally through the Milky Way itself. By introducing a delay in the FRB signal , we can measure the sum of all these contributions.”

Astronomers envision increasingly sensitive methods for detecting bright radio bursts in the future, Gordon said, which would allow them to be discovered at greater distances.

“Ultimately, we are trying to answer the questions: What causes them? Who are his parents and what are his origins? “Hubble observations provide a spectacular view of the surprising types of environments that give rise to these mysterious phenomena,” Fong said.