JWST may have discovered “impossibly massive” galaxies in the early Universe
The discovery of “giant baby galaxies” could change our understanding of the formation of the early Universe.
The James Webb Space Telescope reveals the cosmos like no telescope before it. To date, it makes some of the clearest and most detailed images of known objects in our universe. In addition, astronomers use it to look further into the past than we have ever seen.
This offers an unprecedented glimpse into the early Universe, and a team of researchers has just discovered something remarkable.
This composite image shows the results of JWST’s CEERS survey along with a close-up of each of the six early galaxies that appear very unusual. Photo credit: NASA/STScI/CEERS/TACC/S. Finkelstein/M. Bagley/Z. Levay; NASA/ESA/CSA/I. Labbe
The above images were captured in June 2022 during the JWST Cosmic Evolution Early Release Science (CEERS) survey when the telescope was aimed at a small region of apparently empty space near the Big Dipper. The six inset images each contain a galaxy (circled) that appears to be one of the earliest in the Universe. JWST sees these galaxies as they would have looked about 500 to 800 million years after the Big Bang.
Astronomers verify the age of such galaxies by looking at how red they appear. The light from these objects has been traveling through the universe for billions of years to reach us. As the universe has expanded all this time, the wavelength of light has also expanded. This shifts the wavelength of the light toward the red and infrared ends of the spectrum. JWST is designed to capture different wavelengths of infrared light and when the data is combined to produce images, the shortest wavelengths appear in blue and the longest wavelengths in red.
For the most distant and oldest objects, their light travels so long that it is shifted far enough into the infrared that they only appear at the longest wavelengths that JWST can detect. So to find them you have to search the data for anything that is completely invisible at all but the longest wavelengths. In images like the one above, these are the galaxies that appear the deepest red color.
Based on what astronomers and astrophysicists have discovered about the Universe so far, these old redshift galaxies should be fairly low-mass. After all, a galaxy the size of the Milky Way, with around 100 billion stars, takes billions of years to reach this size and mass.
Or so we thought?
According to an article published this week in the journal Nature, the six galaxies the research team found are not only among the oldest in the CEERS survey data, each appears bright enough to approach the size and mass of the Milky Way!
“It’s bananas,” Erica Nelson, a University of Colorado-Boulder astrophysicist who co-authored the new research paper, said in a statement. “You just don’t expect the early universe to be able to organize itself so quickly. These galaxies shouldn’t have had time to form.”
“The Milky Way forms about one or two new stars every year,” Nelson explained. “Some of these galaxies should form hundreds of new stars every year throughout the history of the universe.”
Not only are these six candidate galaxies found in the CEERS survey data among the oldest, they also appear to be surprisingly massive. Source: NASA/ESA/CSA/I. Labbe
“Those little red dots have too many stars, too soon,” wrote Ivo Labbé, the study’s lead author from Swinburne University of Technology in Melbourne, Australia, in an article on The Conversation. “Stars form from hydrogen gas, and fundamental cosmological theory (“Big Bang”) makes harsh predictions about how much gas is available for star formation.”
“To produce these galaxies so quickly, it takes almost all of the gas in the universe to turn into stars at near 100% efficiency. And that is very difficult, which is the scientific term for impossible. This discovery could change our understanding of how the earliest galaxies in the Universe formed,” Labbé explained.
Right now, Labbé, Nelson and the rest of their team need more data from JWST to confirm the results of their research.
According to Labbé, one of those six galaxies was photographed by JWST in January and turned out to be a “baby quasar.” Basically, a quasar is when the supermassive black hole at the core of a galaxy releases enormous amounts of energy while consuming matter. As a result, quasars glow very brightly, potentially making that particular galaxy appear larger and more massive than it really is.
Labbé doesn’t think all of these galaxies will turn out to be baby quasars.
But even that would be a pretty exciting result, he wrote, “because the origin of supermassive black holes in galaxies is also not understood, and finding baby quasars may just be the key.”
See below: Marvel at the beauty of Webb’s Pillars of Creation
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Thumbnail image courtesy NASA/STScI/CEERS/TACC/S. Finkelstein/M. Bagley/Z. Levay; NASA/ESA/CSA/I. Labbe