Trace of powerful and mysterious radio signal

 Astronomers say they’ve traced the origin of powerful and mysterious radio signal

Astronomers have traced one of the most powerful and distant fast radio bursts ever detected back to its unusual cosmic home: a rare “blob-like” group of galaxies. The unexpected discovery could shed more light on what causes the mysterious radio wave bursts, which have puzzled scientists for years. Scientists have uncovered the source of the mysterious radio signal that took eight billion years to reach us. A new research presented during the 243rd meeting of the American Astronomical Society in New Orleans, Louisiana, said the most distinct and ancient fast radio burst (FRB) came from a location that dates halfway back to the Big Bang. Astronomers led by North western University in the US have found the origin of the most powerful FRB, detected in 2022. FRBs are short but strong radio bursts that flare up and disappear within milliseconds. They produce more energy in one quick burst than the Sun emits in one year. 

The intense signal, named FRB 20220610A, was first detected on June 10, 2022, and it travelled 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 kms). The researchers traced the FRB back to a group of at least seven galaxies using images captured by NASA's Hubble Space Telescope. Their findings suggest the galaxies appear to be interacting with each other and might be en route to a merger. Such rare interactions among galaxies lead to conditions that can trigger an FRB. According to experts, the new research raises questions about all the previous scientific models of FRBs. Fast radio bursts, or FRBs, are intense, millisecond-long bursts of radio waves with unknown origins. The first FRB was discovered in 2007, and since then, hundreds of these quick, cosmic flashes have been detected coming from distant points across the universe.

This particular fast radio burst lasted less than a millisecond, but it was four times more energetic than previously detected FRBs. The burst released the equivalent of our sun’s energetic emissions over the course of 30 years, according to an initial study. Lead researcher Alexa Gordon of Northwestern University said, "Without the Hubble's imaging, it would remain a mystery, whether this FRB originated from one monolithic galaxy or some interacting system. It's these types of environments, these weird ones, that drive us toward a better understanding of the mystery of FRBs." FRBs are short but strong radio bursts that flare up and disappear within milliseconds. They produce more energy in one quick burst than the Sun emits in one year. FRB 20220610A was the most distant fast radio burst recorded. Scientists have discovered up to 1,000 FRBs since first discovering them in 2007. However, the sources behind most of them remain unknown.

Many FRBs release super bright radio waves lasting only a few milliseconds at most before disappearing, which makes them difficult to observe. Earlier studies suggested that FRBs generated near an unidentifiable, formless blob consisting of a single, irregular galaxy or a group of three distant galaxies. However, in the case of FRB 20220610A, there might be at least seven galaxies in incredible proximity to one another.

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 are so close to one another that they could all fit inside the Milky Way galaxy. The study's co-author, Wen-fai Fong, an associate professor of physics and astronomy, said: "There are some signs that the group members are interacting. In other words, they could be trading materials or possibly on a path to merging. These groups of galaxies (called compact groups) are incredibly rare environments in the universe and are the densest galaxy-scale structures we know of." The galaxies in the group seem to be interacting and could even be in the process of merging, which might have triggered the fast radio burst, according to the researchers.