JPL-California Institute of Technology/NASA
This artist’s concept is a top-down view of the Milky Way, a barred spiral galaxy.
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Astronomers have discovered an intriguing phenomenon in the distant Universe: galaxies similar to the Milky Way, challenging important theories about how galaxies evolve.
This distant star system, called CEERS-2112, was discovered by an international team using the James Webb Space Telescope.
Like our home galaxy, the newly discovered CEERS-2112 is a barred spiral galaxy and the most distant galaxy ever observed. The rod at the center of the structure is made of stars.
Ceers-2112 formed shortly after the Big Bang created the universe (estimated to be 13.8 billion years old), and the galaxy’s unique structure was already forming 2.1 billion years later.
Given the distance between Earth and celestial bodies in the early days of the universe, for a telescope like Webb’s to observe light from distant space is essentially like peering into the past.
“Unexpectedly, this discovery reveals that galaxies similar to ours already existed 11.7 billion years ago, when the universe was only 15% of its lifespan.” said Luca Costantin, lead author of the study, in a statement. He is a postdoctoral researcher at the Spanish National Research Council at the Spanish Astrobiologia Center in Madrid.
Astronomers were surprised to discover such a well-structured galaxy at a time when other galaxies were more irregular. Giant spiral galaxies are common in the Milky Way’s cosmic neighborhood, but this was not always the case.
This revelation, made possible by Webb’s sensitive light-detecting capabilities, is changing scientists’ understanding of galaxy formation and the beginning of the universe.
“The discovery of CEERS-2112 suggests that galaxies in the early universe may be as ordered as the Milky Way,” said study co-author Alexander de, a postdoctoral fellow at the University of California, Riverside. La Vega said in a statement. “This is surprising because galaxies were much more chaotic in the early universe, and few had structures similar to the Milky Way.”
The study detailing the findings was published Nov. 8 in the journal Nature.
Astronomers believed that it took billions of years of galactic evolution for large clusters of stars in galaxies to form a central bar, so barred spiral galaxies like the Milky Way are not the same as the universe is now. It was thought that they did not appear until at least half of the age of children. .
Like the Milky Way, a bar shape forms when stars in a spiral galaxy rotate in an orderly manner. Until now, astronomers didn’t think early galaxies were stable enough for bars to form or persist.
However, the discovery of ceers-2112 suggests that this evolution only took about a billion years or less, de la Vega said.
“Almost all bars are found in spiral galaxies,” de la Vega says. “The ceers-2112 bar suggests that galaxies matured and became ordered much faster than previously thought. This suggests that some of our theories about galaxy formation and evolution This means that aspects of this require modification.”
Dela Vega believes astronomers need to change their theoretical models of galaxy formation and evolution to account for the amount of dark matter in early galaxies.
Although dark matter has never actually been detected, it is thought to make up 85% of all matter in the universe. European Space Agency’s Euclid Telescope Designed to map. Dark matter may have played a role in the formation of the bars.
The discovery also suggests that bars can be detected in early galaxies, despite the fact that the oldest galaxies are much smaller.
“The discovery of ceers-2112 paves the way for the discovery of many more bars in this young universe,” said de la Vega. “We initially thought that detecting and estimating the properties of bars in galaxies like CEERS-2112 would be fraught with measurement uncertainties. However, the capabilities of the James Webb Space Telescope and the research team’s Thanks to our expertise, we were able to set strong limits on the size and shape of the bar.”