An international team of researchers has identified a galaxy strikingly similar to our own Milky Way. The distant barred spiral galaxy, named ceers-2112, challenges previous conceptions about galaxy formation and structure in the early universe.
This remarkable astronomical achievement was made possible by the James Webb Space Telescope.
Historically, astronomers believed that barred spiral galaxies like our Milky Way couldn’t exist in the universe’s infancy, considering the universe’s estimated age of 13.8 billion years.
This research, led by the Centro de Astrobiología in Spain, marks a significant shift in our understanding of cosmic timelines.
Alexander de la Vega, a postdoctoral researcher in the Department of Physics and Astronomy at UCR, played a pivotal role in this discovery.
“This galaxy, named ceers-2112, formed soon after the Big Bang,” said de la Vega. “Finding ceers-2112 shows that galaxies in the early universe could be as ordered as the Milky Way. This is surprising because galaxies were much more chaotic in the early universe and very few had similar structures to the Milky Way.”
De la Vega explained that the galactic bar in the center of ceers-2112 is a structure made of stars that is found within spiral galaxies. Galactic bars resemble bars in our everyday lives, such as a candy bar. It is possible to find bars in non-spiral galaxies, he said, but they are very rare.
“Nearly all bars are found in spiral galaxies,” said de la Vega. “The bar in ceers-2112 suggests that galaxies matured and became ordered much faster than we previously thought, which means some aspects of our theories of galaxy formation and evolution need revision.”
The conventional wisdom that galaxies took billions of years to develop structures like bars is upended by this research.
“The discovery of ceers-2112 shows that it can happen in only a fraction of that time, in about one billion years or less,” said de la Vega. He explained that galactic bars are thought to form in spiral galaxies with stars that rotate in an ordered fashion, the way they do in the Milky Way.
“In such galaxies, bars can form spontaneously due to instabilities in the spiral structure or gravitational effects from a neighboring galaxy. In the past, when the universe was very young, galaxies were unstable and chaotic. It was thought that bars could not form or last long in galaxies in the early universe.”
According to de la Vega, the discovery of ceers-2112 has two major implications for astronomy. “First, theoretical models of galaxy formation and evolution will need to account for some galaxies becoming stable enough to host bars very early in the universe’s history.”
“These models may need to adjust how much dark matter makes up galaxies in the early universe, as dark matter is believed to affect the rate at which bars form.”
“Second, the discovery of ceers-2112 demonstrates that structures like bars can be detected when the universe was very young. This is important because galaxies in the distant past were smaller than they are now, which makes finding bars harder. The discovery of ceers-2112 paves the way for more bars to be discovered in the young universe.”
The study is published in the journal Nature.
Image Credit: Luca Costantin/CAB/CSIC-INTA
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