Astronomers have recently made a groundbreaking discovery, detecting a mysterious and extremely powerful burst of radio waves that has traveled an astounding 8 billion years to reach Earth. This remarkable event represents one of the most distant and energetic fast radio bursts (FRBs) ever observed in the cosmos.
FRBs are enigmatic phenomena characterized by intense, millisecond-long bursts of radio waves. Their origins remain a mystery, but they have been a subject of great interest to the scientific community since the discovery of the first FRB in 2007. In the subsequent years, hundreds of these rapid cosmic flashes have been identified emanating from various remote locations in the universe.
The FRB, designated as FRB 20220610A, was exceptionally brief, lasting less than a millisecond. However, during this fleeting moment, it unleashed an energy equivalent to the total emissions of our Sun over the course of 30 years. This remarkable finding was published in a study in the journal Science.
One of the significant challenges in studying FRBs is their extreme brevity, as they typically release super-bright radio waves that last for just a few milliseconds before vanishing. To address this issue, astronomers have relied on powerful radio telescopes to capture and analyze these rapid cosmic events. Notably, the Australian Square Kilometre Array Pathfinder (ASKAP) array of radio telescopes, situated on Wajarri Yamaji Country in Western Australia, played a pivotal role in detecting the FRB in June 2022 and determining its source.
Dr. Stuart Ryder, an astronomer at Macquarie University in Australia and a coauthor of the study, explained the significance of this achievement. “Using ASKAP’s array of radio dishes, we were able to determine precisely where the burst came from,” he said. “Then we used the European Southern Observatory’s Very Large Telescope in Chile to search for the source galaxy, finding it to be older and farther away than any other FRB source found to date and likely within a small group of merging galaxies.”
The research team’s investigation led them to a group of two or three galaxies currently undergoing a process of merging, interaction, and star formation. This observation aligns with prevailing theories suggesting that FRBs may originate from magnetars, highly energetic objects resulting from stellar explosions.
Scientists believe that FRBs offer a unique method for “weighing” the universe by measuring the unaccounted-for matter that resides between galaxies. Ryan Shannon, a professor at Swinburne University of Technology in Australia and a coauthor of the study, explained, “If we count up the amount of normal matter in the Universe — the atoms that we are all made of — we find that more than half of what should be there today is missing.” The elusive matter is believed to exist in the space between galaxies, but its extreme heat and diffuseness make it challenging to detect using conventional techniques.
The discovery holds potential implications for understanding cosmic structure and mass estimation. Shannon noted, “Fast radio bursts sense this ionized material. Even in space that is nearly perfectly empty, they can ‘see’ all the electrons, and that allows us to measure how much stuff is between the galaxies.” This novel approach was initially demonstrated by the late Australian astronomer Jean-Pierre Macquart in 2020.
“J-P showed that the farther away a fast radio burst is, the more diffuse gas it reveals between the galaxies. This is now known as the Macquart relation,” Ryder explained. “Some recent fast radio bursts appeared to break this relationship. Our measurements confirm the Macquart relation holds out to beyond half the known Universe.”
To date, nearly 50 FRBs have been traced back to their sources, with approximately half of them being discovered using ASKAP. Researchers anticipate that future radio telescopes, currently under construction in South Africa and Australia, will facilitate the detection of thousands more FRBs at even greater distances.
“The fact that FRBs are so common is also amazing,” Shannon stated. “It shows how promising the field can be because you’re not just going to do this for 30 bursts; you can do this for 30,000 bursts, make a new map of the structure of the universe, and use it to answer big questions about cosmology.” This remarkable discovery opens up new horizons for understanding the universe and its hidden mysteries.