By Imogen Howse
The most powerful fast radio burst ever detected originated from a “blob-like” collection of galaxies that date halfway back to the Big Bang, reveals a new study.
First discovered in 2007, fast radio bursts, or FRBs, last only a millisecond. Some experts have suggested they may be from an extraterrestrial life form trying to contact Earth.
However, the exact cause and origins of FRBs still remain unconfirmed. Last summer, astronomers from Northwestern University in the US detected a record-breaking FRB, which was not only more energetic than its predecessors but was also farther, and therefore older, than any other previously recorded.
Dubbed FRB 20220610A, originated when the universe was just 5 billion years old. To put this into perspective, the universe is now 13.8 billion years old – and the Earth is just 4.54 billion years old.
Initially, the astronomers thought that the FBR originated near an unidentifiable, amorphous “blob” – which they believed to be either a single, irregular galaxy or a group of three distant galaxies.
But now, using images from NASA’s Hubble Space Telescope, the team have discovered that the FBR’s birthplace is no less than seven galaxies – all of which are in such close proximity that they could fit inside our own Milky Way.
Images also suggest that the collection of galaxies are interacting with one another and therefore could be on the path to a potential merger. These conditions are incredibly rare, which could be what triggered the record-breaking FRB.
“Without the Hubble Space Telescope’s imaging, it would remain a mystery as to whether this FRB originated from one monolithic galaxy or from some type of interacting system. It’s these types of environments — these weird ones — that drive us toward a better understanding of the mystery of FRBs,” said study lead author Alexa Gordon.
“There are some signs that the galaxies are ‘interacting’. In other words, they could be trading materials or possibly on a path to merging. This interaction could trigger bursts of star formations,” said study co-author Wen-Fai Fong, an associate professor of physics and astronomy.
Although up to 1,000 FRBs have been uncovered since they were first discovered in 2007, astronomers have yet to reach a consensus on the possible mechanisms behind the blinding flashes.
It is generally agreed that FRBs must involve a compact object – such as a black hole or a neutron star – but the exact source behind them remains stubbornly uncertain.
Northwestern University’s discovery could therefore be a step towards understanding the mysterious phenomena of FBRs – which could in turn be a step towards understanding the true nature of the universe itself.
“This is because when FRBs finally meet our telescopes – they have already traveled for billions of years from the distant, early universe. During this cross-universe odyssey, they interact with material along the way. FRBs therefore travel through their host galaxy, across the universe, and finally through the Milky Way. From a time delay in the FRB signal itself, we can measure the sum of all of these contributions,” explained Professor Fong.
To continue to probe FRBs and their origins, astronomers need to detect and study more of them. And with technology continually becoming more sensitive, the team at Northwestern University believes that more detections — and possibly the prospect of capturing incredibly faint FRBs — are right around the corner.
“With a larger sample of distant FRBs, we can begin to study the evolution of FRBs and their host properties by connecting them to more nearby ones and perhaps even start to identify more strange populations. FRB 20220610A has a truly rare birthplace. Despite hundreds of FRB events discovered to date, only a fraction of those have been pinpointed to their host galaxies,” said study co-author Yuxin (Vic) Dong.
“And, within that small fraction, a few came from a dense galactic environment – but none have ever been seen in such a compact group. In the near future, FRB experiments will increase their sensitivity, leading to an unprecedented rate in the number of FRBs detected at these distances. Astronomers will therefore soon learn just how special the environment of this FRB was,” added Gordon.
She is due to present the findings at the 243rd annual meeting of the American Astronomical Society in New Orleans, Louisiana.
Produced in association with SWNS Talker