New research, just published today, has challenged long-held beliefs about galaxies in the early universe, revealing that they are more similar to our Milky Way than previously imagined. Thanks to the James Webb Space Telescope (JWST), a team of international researchers, including those from The University of Manchester and the University of Victoria in Canada, has made groundbreaking discoveries.
These galaxy types, akin to our Milky Way, extend far back into the universe’s history, with some dating back over 10 billion years. In contrast to earlier assumptions, the Milky Way, characterized by its disk-like shape and spiral arms, appears to be a prevalent galaxy type throughout the universe. This revelation suggests that these galaxies, with their potentially life-friendly formation history, are more common than previously thought.
Previously, astronomers believed that such disk galaxies were too fragile to exist in the early universe, where galaxy mergers were more frequent and deemed capable of destroying their delicate structures. However, the latest research, featured in The Astrophysical Journal, asserts that these disk galaxies are ten times more abundant than previously believed, thanks to the capabilities of the JWST.
Christopher Conselice, a professor of extragalactic astronomy at The University of Manchester, noted that their prior observations with the Hubble Space Telescope led them to believe that disk galaxies only emerged when the universe was about 6 billion years old. However, the JWST findings push the formation of Milky Way-like galaxies almost to the universe’s inception, fundamentally reshaping our understanding of cosmic evolution.
Lead author Leonardo Ferreira, from the University of Victoria, highlighted that for over three decades, it was assumed that these disk galaxies were rare in the early universe due to frequent violent galaxy encounters. The abundance of such galaxies discovered by JWST underscores the instrument’s power and suggests that galaxy structures take shape much earlier than anticipated.
Traditionally, scientists believed that galaxies like the Milky Way were rare throughout cosmic history, forming only when the universe was relatively mature. The Hubble Space Telescope previously led astronomers to believe that galaxies primarily exhibited irregular and peculiar structures resembling mergers. However, the enhanced capabilities of JWST now provide a clearer view of these galaxies’ true structures.
This research challenges our understanding of how quickly “structure” forms in the universe and raises intriguing questions about dark matter’s role in the early universe. In essence, astronomers must reevaluate their understanding of the formation and evolution of galaxies over the past 10 billion years based on these groundbreaking results.
Source: University of Manchester