Astronomers have discovered the most distant example of a galaxy similar to our Milky Way galaxy in the universe. While the universe is only two billion years old, the newly discovered spiral galaxy Ceers-2112 appears to have a belt of stars and gas cutting through its heart, like a slash cutting through a no-smoking sign. The Milky Way, also a spiral galaxy, has a similar band. Scientists suspect that the Milky Way’s band rotates cylindrically like a toilet paper holder does when you unwrap it, funneling gas into the center of the galaxy and causing bursts of star formation.

Astronomers previously thought that this galactic structure marked the end of a galaxy’s formative years; It was therefore expected to be seen only in older galaxies that might have reached full maturity, perhaps in galaxies that existed halfway through the universe’s evolution. In fact, previous Hubble Space Telescope observations of galaxy morphology showed that there were very few barred galaxies in the early universe.

But new findings from data from the James Webb Space Telescope (JWST) conclude that it is not necessarily true that barred spirals have been wandering around the universe for so long. The discovery of the spiral galaxy ceers-2112 shows that galaxies like ours already existed 11.7 billion years ago, “when the universe had only 15 percent of its lifetime,” said Luca Costantin, an astrophysicist at the Center for Astrobiology in Madrid. The new study reported Space.com.

JWST collects six times more light than Hubble, allowing more detailed imaging of distant galaxies. Ceers-2112 is observed at a redshift of 3 when the universe was 2,100 million years old. Essentially, this means that light from the galaxy took 11.7 billion years to reach JWST, Costantin said. This is a surprising finding, because galactic bars can be seen in about two-thirds of all spiral galaxies, but bars are thought to have emerged about 4 billion years after the birth of the universe.

Studying the detailed morphology of distant galaxies is “important for understanding their history, which opens the door to new scenarios of galaxy formation and evolution,” said co-author Cristina Cabello, a researcher at the Institute of Physical Particles and Space in Madrid. , the message says.

The presence of a bar in Ceers-2112, for example, challenges current theoretical models predicting the physical conditions of the early universe and likely prevents the formation of barred galaxies altogether, Constantin said.

“Theoretical predictions from cosmological simulations make it really difficult to reproduce such systems in those periods,” he told Space.com. “We now need to understand what key physical component is missing in our models – if any.”

Moreover, such studies are shaping our understanding of the role of dark matter in the early universe.

Astronomers estimate that 85 percent of all matter in the universe is dark matter, a mysterious substance that cannot be detected by telescopes because it does not interact with light at all. Dark matter is believed to have a radical impact on the evolution of galaxies and star formation even 380,000 years after the Big Bang. But the results of the new study show that when the universe was about two billion years old, at least in the case of Ceres-2112, the galaxy’s evolution was driven by ordinary matter, not dark matter. According to the study, the morphology of the galaxy indicates that the proportion of dark matter in Ceers-2112’s galactic bar is very low, instead being dominated by ordinary matter.

“This finding confirms that the evolution of this galaxy was dominated by baryons (the ordinary matter from which we are made) rather than dark matter, although they were abundant at a time when the universe was only 15 percent of its true age,” the study said. co-author Jairo Abreu, a researcher at the University of La Laguna.

“JWST will revolutionize our understanding of the early universe with just one year of observations,” Constantin said. “Over the next 5-10 years, I personally plan to continue to exploit their extraordinary capabilities by exploring the detailed structure of the first galaxies assembled in the universe.”