Universe breakers: James Webb telescope spots six ancient galaxies

23 Feb 2023

The six candidate galaxies, which existed roughly 600m years after the Big Bang, based on observations taken from the James Webb Space Telescope. Image: NASA, ESA, CSA, I. Labbe (Swinburne University of Technology). Image processing: G. Brammer (Niels Bohr Institute’s Cosmic Dawn Center at the University of Copenhagen).

Researchers claim these ancient galaxies appear to contain hundreds of billions of stars, making them far larger than what was previously thought possible so soon after the Big Bang.

New observations from the James Webb Space Telescope could shake up our understanding of the early universe, as researchers have detected what appear to be large, ancient galaxies.

Astronomers analysed the first dataset released by the powerful space observatory, which uses various instruments to see the light from ancient stars and galaxies. These images help to give researchers a glimpse into what the early universe looked like.

Within this dataset, a research team spotted six objects that appear to be ancient galaxies. These galaxies would have existed when the universe was around 3pc of its current age, roughly 500m to 700m years after the Big Bang.

In a paper published in the scientific journal Nature, the team said these galaxies are  far larger and more developed than what would be expected in the early days of the universe.

Joel Leja, assistant Professor at Penn State who was involved in the study, said the team only expected to find “young, baby galaxies” when peering into this ancient period of time.

“We’ve discovered galaxies as mature as our own in what was previously understood to be the dawn of the universe,” Leja said.

The James Webb telescope has previously detected ancient galaxies, but they appeared far smaller than these new potential galaxies. Initial calculations suggest some of these galaxies could contain as many stars as the Milky Way.

“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.”

Leja said the idea that massive galaxy formation began so early in the history of the universe “upends” our understanding on the early universe. He added that a spectrum image of these galaxies will help to determine the validity of the team’s findings.

“We’ve been informally calling these objects ‘universe breakers’ – and they have been living up to their name so far,” Leja said.

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Leigh Mc Gowran is a journalist with Silicon Republic