A fast, mysterious radio blast that traveled 8 billion years to reach Earth

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Astronomers have discovered a mysterious burst of radio waves that took 8 billion years to reach Earth. The fast radio burst is one of the most distant and energetic explosions ever observed.

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.

The explosion, dubbed FRB 20220610A, lasted less than a millisecond, but in that fraction of an instant, it released the equivalent of our Sun’s energy emissions over 30 years, according to a study published Thursday in the journal. Sciences.

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

Radio telescopes have helped astronomers track these rapid cosmic flashes, including the ASKAP radio telescope array, located in the Wagari-Yamaji district of Western Australia. Astronomers used ASKAP to detect fast radio bursts in June 2022 and determine where they originated.

“Using ASKAP’s array of (radio) dishes, we were able to pinpoint the source of the explosion,” Dr. Stuart Ryder, co-author of the study and an astronomer at Macquarie University in Australia, said in a statement. “We then used the European Southern Observatory’s Very Large Telescope in Chile to search for the source galaxy, and found that it was older and (more distant) than any other FRB found so far and likely within a small group of merging galaxies.”

The research team tracked the explosion to what appears to be a group of two or three galaxies that are in the process of merging, interacting, and forming new stars. This result is consistent with current theories that suggest that fast radio bursts may come from magnetars, or high-energy objects produced by star explosions.

Scientists believe that fast radio bursts may be a unique method that can be used to “weigh” the universe by measuring matter between galaxies whose fate remains unknown.

“If we count the amount of natural matter in the universe – the atoms of which we are all made – more than half of what should be there today is missing,” said Ryan Shannon, co-author of the study and professor at Swinburne University. Technology Australia, in a statement. “We think the missing matter is hiding in intergalactic space, but it may be so hot and diffuse that it is impossible to see using normal techniques.”

So far, the results of current methods used to estimate the mass of the universe do not agree with each other, suggesting that the scale of the entire universe is not included.

“Fast radio bursts sense this ionized material,” Shannon said. “Even in space that is almost completely empty, they can see all the electrons, and this allows us to measure the amount of stuff that exists between galaxies.”

This method of using fast radio bursts to detect missing matter was demonstrated by The late Australian astronomer Jean-Pierre Macquart in 2020.

“JP showed that the (farther away) the fast radio burst is, the more intergalactic the gas it detects is spread out. This is now known as the Macquart relationship,” Ryder said. “Some recent fast radio bursts appear to have broken this relationship.
Our measurements confirm that Macquart’s relationship applies beyond half of the known universe.

Nearly 50 fast radio bursts have been traced back to their points of origin, about half of which were found using ASKAP.

“Although we still don’t know what causes these massive bursts of energy, the paper confirms that fast radio bursts are common events in the universe and that we will be able to use them to detect intergalactic matter, and better understand the structure of galaxies.” The universe,” Shannon said.

Astronomers said they hope future radio telescopes, currently under construction in South Africa and Australia, will enable the detection of thousands of fast radio bursts at greater distances.

“The fact that fast radio bursts are so common is also surprising,” Shannon said. “It shows how promising this field can be, because you won’t just do it for 30 bursts, you can do it for 30,000 bursts, create a new map of the structure of the universe, and use it to answer big questions.” “On cosmology.”