Webb Images: Early Massive Galaxies That "Shouldn't Exist"

 

(click on image to enlarge)

The James Webb Space Telescope delivers an astronomical bombshell:

On July 12, 2022 the universe changed forever. Scientist still don’t know for sure what happened, but on that Tuesday the first “deep field” images from the James Webb Space Telescope were released—and astronomy has been in a frenzy ever since.

Over six months later the story of how our universe changed that day is becoming clearer, but the cause was clear—JWST’s ability to see back 13.5 billion years near the beginning of the universe as we know it.

“When we got the data [that day] everyone just started diving in and these massive things popped out really fast,” said Joel Leja, assistant professor of astronomy and astrophysics at Penn State and co-author of a paper published today in Nature about the revolutionary data from JWST. He’s talking about six galaxies in JWST’s images existing 500-700 million years after the Big Bang—when the universe was only 3% of its current age—that appeared far more massive than anyone expected.

“It’s bananas,” said Erica Nelson, co-author of the new research and assistant professor of astrophysics at the University of Colorado Boulder. “You just don’t expect the early universe to be able to organize itself that quickly. These galaxies should not have had time to form.” [snip]

“We’ve been informally calling these objects ‘universe breakers’—and they have been living up to their name so far,” says Leja. The data in the images of these early galaxies (main image, above) effectively means that the early stars had as much as 100 times greater mass than astronomers previously thought. It’s thought that the galaxy on the lower-left could contain as many stars as our Milky Way galaxy does today despite being 30 times more compact.

The galaxies are red because old light in the universe is red because the universe is expanding. Red light has the longest wavelength.

“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,” said Leja, who with colleagues spent months trying to figure out how they are so big and bright. “My first thought was we had made a mistake and we would just find it and move on with our lives, but we have yet to find that mistake, despite a lot of trying ... even if we cut the sample in half, this is still an astounding change.”

The kicker?

“What’s funny is we have all these things we hope to learn from JWST and this was nowhere near the top of the list,” said Leja. “We’ve found something we never thought to ask the universe—and it happened way faster than I thought.”

Ain't science great?!

(Image:  "six candidate massive galaxies, seen 500-800 million years after the Big Bang. One of the sources (bottom left) could contain as many stars as our present-day Milky Way, but is 30 times more compact" /NASA, ESA, CSA, I. Labbe)