Researchers Find Disk Galaxies Like Milky Way In The Early Universe27th Sep 2023
Researchers have disproved a theory that ‘disk’ galaxies were too fragile to form and exist during the universe’s earliest days. The discovery came after an international team of researchers, including scientists from the University of Manchester and the University of Victoria in Canada, found galaxies like the Milky Way in the furthest recesses of space.
They also discovered that these spiral galaxies formed over 10 billion years ago. In fact: “[they] dominate throughout the universe and are surprisingly common.”
Christopher Conselice, Professor of Extragalactic Astronomy at The University of Manchester, said: “[the] JWST results show that disk galaxies like our own Milky Way, are the most common type of galaxy in the Universe. This implies that most stars exist and form within these galaxies… changing our complete understanding of how galaxy formation occurs.”
Why Astronomers Believed Disk Galaxies To Be Impossible During The Early Universe
Originally, scientists contended that spiral galaxies – otherwise known as disk galaxies – were not robust enough to be one of the first galaxies to form after the Big Bang. This was due to the belief that spiral galaxies could not handle the galaxy mergers that happened frequently during the universe’s infant years. Additionally, scientists believed disk galaxies to be “relatively rare through[out] cosmic history”, convinced they could have only formed during the universe’s middle-ages.
Initially, disk galaxies, like the Milky Way, were purely observed within the nearby universe. They are circular and contain spiral arms and are the type of galaxy where life can form, Manchester University said. However, the international research team discovered that disk galaxies “go further back in the universe’s history” than first thought.
‘Flipping The Narrative’: Finding Disk Galaxy’s From 10 Billion Years Ago
Unlocked through the use of JWST, researchers discovered that disk galaxies existed during the universe’s earliest days, and are now considered “the most common type”. They also unearthed that many spiral galaxy’s have existed for over 10 billion years, and according to Manchester University, the discovery is: “flipping the entire narrative of how scientists think about [galaxy] structure formation.” Adding: “the universe forms much quicker than anyone had anticipated.”
Why Disk Galaxies Were Only Just Discovered In The Early Universe
Prior to the construction of JWST, scientists viewed the observable universe through the Hubble Space Telescope. Due to Hubble’s limitations, astronomers were led to believe merged galaxy’s did not resemble that of a disk galaxy due to their warped shape. Hence why astronomers believed disk galaxy formation to be impossible post Big Band. However, Hubble’s successor, JWST, is able to see further due to its infrared telescope. It can also capture galaxies in their earliest form, which led to the discovery that they are 10 times more common than other galaxy types, Manchester University said.
Leonardo Ferreira, Lead author from the University of Victoria, said: “For over 30 years it was thought that these disk galaxies were rare in the early Universe due to the common violent encounters that galaxies undergo. The fact that JWST finds so many is another sign of the power of this instrument and that the structures of galaxies form earlier in the Universe, much earlier in fact, than anyone had anticipated. “
Professor Conselice added: “These results also suggest important questions about dark matter in the early universe which we know very little about. Based on our results astronomers must rethink our understanding of the formation of the first galaxies and how galaxy evolution occurred over the past 10 billion years.”