In a groundbreaking study, researchers at the University of Missouri (Mizzou) have uncovered evidence that spiral galaxies were more prevalent in the early universe than previously believed. This discovery challenges long-standing astronomical theories about the timeline of galaxy formation.
“Scientists formerly believed most spiral galaxies developed around 6 to 7 billion years after the universe formed,” explained Yicheng Guo, an associate professor in Mizzou’s Department of Physics and Astronomy and a co-author of the study. “However, our study shows spiral galaxies were already prevalent as early as 2 billion years afterwards. This means galaxy formation happened more rapidly than we previously thought.”
The implications of this study are significant, offering new insights into the evolution of galaxies like the Milky Way, Earth’s home galaxy. Understanding the formation and evolution of spiral galaxies is crucial for piecing together the history of the cosmos.
“Knowing when spiral galaxies formed in the universe has been a popular question in astronomy because it helps us understand the evolution and history of the cosmos,” said Vicki Kuhn, a graduate student in Mizzou’s Department of Physics and Astronomy who led the study. “Many theoretical ideas exist about how spiral arms are formed, but the formation mechanisms can vary amongst different types of spiral galaxies. This new information helps us better match the physical properties of galaxies with theories — creating a more comprehensive cosmic timeline.”
The study leveraged recent images from NASA’s James Webb Space Telescope (JWST), revealing that nearly 30% of galaxies exhibited a spiral structure approximately 2 billion years after the universe’s formation. This finding significantly updates the universe’s origin story, which was previously constructed using data from NASA’s Hubble Space Telescope.
“Using advanced instruments such as JWST allows us to study more distant galaxies with greater detail than ever before,” Guo said. “A galaxy’s spiral arms are a fundamental feature used by astronomers to categorise galaxies and understand how they form over time. Even though we still have many questions about the universe’s past, analysing this data helps us uncover additional clues and deepens our understanding of the physics that shaped the nature of 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 co-authors 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.
This research was also presented by Kuhn at the 244th meeting of the American Astronomical Society in Madison, Wisconsin, drawing attention from astronomers worldwide eager to reassess their understanding of cosmic history in light of these new findings.
More from: Science
