Using the first dataset released by the James Webb Space Telescope (JWST), an international team of scientists have discovered something surprising– evidence of six massive galaxies that existed during the early days of our universe.
“These objects are way more massive than anyone expected,” said Joel Leja, an astronomer and astrophysicist at Penn State University, in a statement. “We expected only to find tiny, young, baby galaxies at this point in time, but we’ve discovered galaxies as mature as our own in what was previously understood to be the dawn of the universe.”
[Related: Astronomers are already using James Webb Space Telescope data to hunt down cryptic galaxies.]
Leja is co-author of a study published February 22 in the journal Nature that could change some of our preconceived notions of how galaxies form. These newly discovered galaxies themselves date back to about 500 to 700 million years after the Big Bang. JWST has infrared-sensing instruments on board that can detect light that was emitted by the most ancient stars and galaxies, allowing astronomers to see roughly 13.5 billion years back in time.
“This is our first glimpse back this far, so it’s important that we keep an open mind about what we are seeing,” Leja said. “While the data indicates they are likely galaxies, I think there is a real possibility that a few of these objects turn out to be obscured supermassive black holes. Regardless, the amount of mass we discovered means that the known mass in stars at this period of our universe is up to 100 times greater than we had previously thought. Even if we cut the sample in half, this is still an astounding change.”
Since these six galaxies were far more massive than anyone on the team expected them to be, they could upend previous notions about the galaxy formation at the very beginning of the universe.
“The revelation that massive galaxy formation began extremely early in the history of the universe upends what many of us had thought was settled science,” said Leja. “We’ve been informally calling these objects ‘universe breakers’ — and they have been living up to their name so far.”
The authors argue that the “universe breakers” are so large, that almost all modern cosmological models fail to explain how these star systems could have formed.
[Related: Our universe mastered the art of making galaxies while it was still young.]
“We looked into the very early universe for the first time and had no idea what we were going to find,” Leja said. “It turns out we found something so unexpected it actually creates problems for science. It calls the whole picture of early galaxy formation into question.”
One way that the team can confirm their new findings is with a spectrum image that could provide data on the true distances between us and the mysterious galaxies, as well as the gasses and other elements present. It would also paint a more clear picture of what these galaxies looked like billions of years ago.
“A spectrum will immediately tell us whether or not these things are real,” Leja said. “It will show us how big they are, how far away they are. What’s funny is we have all these things we hope to learn from James Webb and this was nowhere near the top of the list. We’ve found something we never thought to ask the universe — and it happened way faster than I thought, but here we are.”
NASA released JWST’s first full-color images and spectroscopic data on July 12, 2022. One of JWST’s primary goals this year is to better map and create a timeline of the earliest days of the universe with its high resolution and infrared spotting capabilities.