The discovery of a huge disk-shaped galaxy, which may be the oldest to be discovered so far, may challenge mankind's existing understanding of how galaxies are born and how they attain their eventual shape and size, ScienceDaily reports.
While disk-shaped galaxies like the Milky Way Galaxy apparently reached their current considerable size billions of years after the Big Bang (which is believed to have taken place some 13.8 billion years ago), the new study suggests that the galaxy in question, DLA0817g (also known as the Wolfe Disk), formed just 1.5 billion years after the Big Bang, the media outlet notes.
"While previous studies hinted at the existence of these early rotating gas-rich disk galaxies, thanks to ALMA we now have unambiguous evidence that they occur as early as 1.5 billion years after the Big Bang," lead author Marcel Neeleman of the Max Planck Institute for Astronomy said.
This discovery is reportedly poised to challenge many existing galaxy formation simulations which postulate that such massive galaxies "at this point in the evolution of the cosmos grew through many mergers of smaller galaxies and hot clumps of gas".
"Most galaxies that we find early in the universe look like train wrecks because they underwent consistent and often 'violent' merging," Neeleman said. "These hot mergers make it difficult to form well-ordered, cold rotating disks like we observe in our present universe."
Spotted via the Atacama Large Millimeter/submillimeter Array (ALMA), the galaxy was named after astrophysicist Arthur Wolfe who passed away in 2014 and who "was one of the first to suggest that disk galaxies existed in the universe’s infancy", Science News points out.
"He was right, at least partially," said J. Xavier Prochaska of the University of California, co-author of the new study and a former student of Wolfe . "He deserves credit for having planted that flag against all conventional wisdom."