Milky Way-like galaxies discovered by Mizzou scientists

Vicki Kuhn, a graduate student in the University of Missouri's Department of Physics and Astronomy, spearheaded the recent study exploring the early universe. Kuhn's interest in astronomy ignited during her high school years.

Researchers at the University of Missouri are delving into the past, unveiling new insights about the early universe. By observing light that has traveled for billions of years, they can now examine how galaxies appeared in ancient times.

Mizzou scientists discover more Milky Way-like galaxies in the early universe

The study led by the Mizzou team has revealed that spiral galaxies were more prevalent in the early universe than previously believed.

"Scientists once thought that most spiral galaxies formed around 6 to 7 billion years after the universe's creation," explained Yicheng Guo, an associate professor in Mizzou's Department of Physics and Astronomy and co-author of the study. "Our findings indicate that spiral galaxies were already widespread as early as 2 billion years after the universe began. This suggests that galaxy formation occurred more rapidly than we had assumed."

This discovery could enhance our understanding of the formation of spiral galaxies like the Milky Way, which is Earth's home galaxy.

"Determining when spiral galaxies formed is a crucial question in astronomy because it helps us trace the evolution and history of the cosmos," noted Vicki Kuhn, the lead researcher of the study. "There are many theoretical models about how spiral arms form, but the mechanisms can differ among various types of spiral galaxies. This new data allows us to better align the physical properties of galaxies with theoretical models, creating a more detailed cosmic timeline."

Several of the spiral galaxies analyzed by the researchers

Photo credit: Vicki Kuhn

The researchers utilized recent images from NASA's James Webb Space Telescope (JWST) and found that approximately 30% of galaxies exhibited a spiral structure about 2 billion years after the universe's inception. This significant finding updates the narrative of the universe's origin, previously based on data from NASA's Hubble Space Telescope.

"Using advanced instruments like the JWST enables us to study more distant galaxies in greater detail than ever before," Guo said. "A galaxy's spiral arms are a key feature used by astronomers to classify galaxies and understand their formation over time. While many questions about the universe's past remain, analyzing this data provides further clues and deepens our comprehension of the physics that shaped our universe."

The study, titled "JWST Reveals a Surprisingly High Fraction of Galaxies Being Spiral-like at 0.5 ≤ z ≤ 4," was published in The Astrophysical Journal Letters. Additional contributors include Alec Martin, Julianna Bayless, Ellie Gates, and AJ Puleo. The project received support from University of Missouri Research Council grants and the Missouri Space Grant Consortium.

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