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Researchers have discovered a distant disk galaxy with characteristics strikingly similar to our own Milky Way galaxy, which could change our understanding of how galaxies form.
The study, led by astronomers at Leiden University in the Netherlands, says the galaxy, named REBELS-25, is much more orderly than existing science suggests it is.
REBELS-25 is much younger than our galaxy, but rather than appearing blocky and chaotic like other early galaxies, it already shares its rotation and structure, researchers said on October 7 This was said in a statement released on the day.
“Our understanding of galaxy formation predicts that most early galaxies appear small and messy,” Jacqueline Hodge, an astronomer at Leiden University and co-author of the study, said in a statement. .
Early galaxies tend to be incredibly slow at merging to form smoother shapes, and researchers say it takes our Milky Way galaxy billions of years to form a neat structure. said.
The light that reached Earth from REBELS-25 was emitted just 700 million years after the universe formed 13.8 billion years ago, a surprisingly short period of time for the universe to form in such an orderly manner. It is said that
Lucy Rowland, a PhD student at Leiden University, said: “Seeing galaxies that are so similar to our own Milky Way and have strong rotational dominance is a great example of how the early galaxies evolved into the universe we know today. “This raises questions about our understanding of how well-ordered galaxies evolve.” said the study’s lead author in a statement.
The rotation and structure of this galaxy were observed using the Atacama Large Millimeter/submillimeter Array (ALMA) telescope in northern Chile.
The researchers also found data that suggests more advanced features, such as spiral arms, and plan to carry out further observations to see if these actually exist.
“Finding further evidence of a more evolved structure would be an interesting discovery, as this would be the most distant galaxy in which such a structure has been observed to date,” Rowland said.
Andrew Brain, a professor of astrophysics at the University of Leicester who was not involved in the paper, said REBELS-25 was “a bit unusual” but “not revolutionary”.
Blaine highlighted the role of ALMA in finding examples of certain types of galaxies that had previously been produced only in simulations.
“Without ALMA, we would not have had the ability to identify the entities because individual entities would be too small to detect in a reasonable amount of time, and it would be difficult to search for a large enough sample of candidates. Because I couldn’t do it,” he told CNN. “ALMA also reveals finer details than previous telescopes.”
Brain said more research is needed to change scientists’ understanding of galaxy formation.
“The question would be whether they are extremely rare or whether all galaxies go through stages like this,” he says. “If they are common, we need to fine-tune the model.”
Dave Clements, a reader in astrophysics at Imperial College London who was not involved in the paper, said finding a galaxy like REBELS-25 was “quite surprising”.
“The universe at that time is thought to have been much more chaotic, with interactions and mergers of galaxies expected to destroy the relatively fragile structure of the disk. It’s what it looks like,” he told CNN.
“Is it just a very rare galaxy that has lived an unexpectedly quiet life by the time we see it? Or are these observations suggesting that the early stages of galaxy formation are as we think it is?” Is it telling us that it doesn’t work?” We don’t know at this point. ”
The research is available as a preprint (a scientific paper that has not gone through the peer-review process) and has been accepted for publication in Monthly Notices, a journal of the Royal Astronomical Society.
