“These objects are much larger than anyone expected,” said Joel Ledja, an assistant professor in the Department of Astronomy and Astrophysics at the University of Pennsylvania, who models the light from these galaxies. “At this time we expected to find only small, young baby galaxies, but we found galaxies as mature as ours in what was previously thought to be the star of the Universe.”

Using the first dataset published by NASA’s James Webb Space Telescope, an international team of scientists has discovered objects as mature as the Milky Way, when the universe was only 3% of its current age, about 500-700 million years after the Big Bang. . The telescope is equipped with infrared sensors that can detect the light emitted by the earliest stars and galaxies. Leia essentially allows scientists to see some 13.5 billion years ago in time, near the beginning of the universe as we know it.

“This is our first look this far back, so it’s important that we keep an open mind about what we’re seeing,” Leia said. “Although the data suggest that these are likely galaxies, I think there is a real possibility that some of these objects will be eclipsed by supermassive black holes. Still, the mass we found means that the known mass of stars at this time of our universe was 100 times greater than we previously thought. Even if we split the sample in half,” he said. , it would still be an impressive change.”

In an article published today (February 22, 2023) in the journal NatureResearchers show evidence that six galaxies are much larger than anyone expected, challenging what scientists previously understood about the formation of galaxies at the beginning of the universe.

“Finding that the formation of large galaxies began so early in the history of the universe turns upside down what most of us thought was a solid scientific conclusion,” Leia said. “We have unofficially called these objects ‘universe destroyers,’ and so far they have lived up to their name.”

Leia explained that the galaxies the team discovered were so large that they contradicted 99% of cosmology models. Accounting for such a large mass would require either changing cosmology models or revising the scientific understanding of galaxy formation in the early universe – galaxies started out as small clouds of stars and dust that gradually grew over time. Both scenarios require fundamental changes in our understanding of how the universe formed, he added.

“It was our first look at the very early universe and we had no idea what we were going to find,” Leia said. “It turns out that we actually found something unexpected enough to pose a problem for science. It questions the whole picture of early galaxy formation.”

On July 12, NASA released the first full-color images and spectroscopic data from the James Webb Space Telescope. The largest infrared telescope in space, Webb was designed to see the birth of the cosmos, its high resolution allowing observation of objects too old, distant or faint for the Hubble Space Telescope.

“Once we got the data, everybody started diving into the topic and these big things came out very quickly,” Leia said. “We started modeling and tried to figure out what it was because they were so big and shiny. My first thought was that we made a mistake and we’re going to find it and move on. But despite numerous attempts, we haven’t found this error yet.”

Leia explained that one way to confirm the team’s finding and clear any remaining doubts is to take a spectral image of the large galaxies. This will give the team data on the gases and other elements that make up the galaxies, as well as the actual distances. The team can then use the data to model a clearer picture of what galaxies look like and how big they actually are.

“The ghost will tell us right away if these are real,” Leia said. “It will show us how big they are, how far they are. Funny, we had all these things we hoped to learn from James Webb, and that wasn’t at the top of the list. We found something we never thought we’d want from the universe – and it happened much faster than I thought, but here we are.