Scientists discover more Milky Way-like galaxies in the early universe, advancing our understanding of how galaxies formed

University of Missouri scientists are peering into the past and uncovering new clues about the early universe. Because light takes a long time to travel through space, they are now able to see what galaxies looked like billions of years ago.

In a new study, Mizzou scientists have found that spiral galaxies were more common in the early universe than previously thought. The work appears in The Astrophysical Journal Letters.

“Scientists previously believed that most spiral galaxies evolved about 6 to 7 billion years after the formation of the universe,” said Yicheng Guo, an associate professor in Mizzou’s Department of Physics and Astronomy and co-author of the study. “However, our study shows that spiral galaxies predominated as early as 2 billion years later. This means that galaxy formation occurred faster than we previously thought.”

The finding could help scientists better understand how spiral galaxies like the Milky Way, Earth’s home galaxy, formed over time.

“Knowing when spiral galaxies formed in the universe is a popular question in astronomy because it helps us understand the evolution and history of the universe,” said Vicki Kuhn, a graduate student in Mizzou’s Department of Physics and Astronomy who led the study.

“There are many theoretical ideas about how spiral arms form, but the formation mechanisms can be different for different types of spiral galaxies. This new information helps us better match the physical properties of galaxies with theories – to create a more comprehensive cosmic timeline.”

Using recent images from NASA’s James Webb Space Telescope (JWST), scientists have found that nearly 30% of galaxies have a spiral structure about 2 billion years after the universe began. The discovery provides a major update to the universe’s origin story, as previously told using data from NASA’s Hubble Space Telescope.

Studying distant galaxies with JWST gives Gu, Kuhn and other scientists the opportunity to solve the cosmic puzzle by determining the meaning of each key.

“Using advanced instruments like JWST allows us to study more distant galaxies in greater detail than ever before,” Guo said. “Galaxy spiral arms are a fundamental element used by astronomers to categorize galaxies and understand how they form over time. While we still have many questions about the universe’s past, analyzing this data helps us uncover more clues and deepens our understanding of physics.” that shaped the nature of our universe.”

Kuhn presented the study at the 244th meeting of the American Astronomical Society in Madison, Wisconsin.