JWST researchers have been able to locate a tiny distant galaxy which originated around 500 million years after the Big Bang – in the universe’s youth
Observations from the James Webb Space Telescope (JWST) looking 13 billion years into the past discovered one of the smallest galaxies to date. This distant galaxy generated new stars at an extremely high rate for its size.
The University of Minnesota Twin Cities-led team which discovered this distant galaxy noted that it is one of the smallest discovered at this distance, which could help astronomers learn more about the oldest galaxies, present after the Universe came into existence.
“We’ve never looked at galaxies when the universe was this young in this level of detail”
The JWST can collect about 10 times as much light as the Hubble Space Telescope
Using spectroscopy to measure how far away the distant galaxy was, as well as measure some of its physical and chemical properties, the researchers aimed to answer a huge question in astronomy: how did the Universe become reionized?
Accessing an entirely new window of data, the James Webb Space Telescope was able to collect about 10 times as much light as the Hubble Space Telescope.
Additionally, the JWST is much more sensitive at redder, longer wavelengths in the infrared spectrum, and can observe a wide enough field to image an entire galaxy cluster at once.
Overall, researchers were able to locate this tiny distant galaxy because of a phenomenon called ‘gravitational lensing’, where mass, such as that in a galaxy or galaxy cluster, bends and magnifies light. A galaxy cluster lens caused this small background galaxy to appear 20 times brighter than it would if the cluster were not magnifying its light.
Using spectroscopy to discover the history of the universe
Patrick Kelly, senior author of the paper and an assistant professor in the University of Minnesota School of Physics and Astronomy, said: “This galaxy is far beyond the reach of all telescopes except the James Webb, and these first-of-their-kind observations of the distant galaxy are spectacular.
“Here, we’re able to see most of the way back to the Big Bang, and we’ve never looked at galaxies when the universe was this young in this level of detail. The galaxy’s volume is roughly a millionth of the Milky Way’s, but we can see that it’s still forming the same numbers of stars each year.”
“We’re seeing things that previous telescopes would have ever been able to capture”
Hayley Williams, first author of the paper and a Ph.D. student at the Minnesota Institute for Astrophysics, added: “The galaxies that existed when the Universe was in its infancy are very different from what we see in the nearby Universe now.
“This discovery can help us learn more about the characteristics of those first galaxies, how they differ from nearby galaxies, and how the earlier galaxies formed.
“The James Webb Space Telescope has this amazing capability to see extremely far into the universe. This is one of the most exciting things about this paper. We’re seeing things that previous telescopes would have ever been able to capture. It’s basically getting a snapshot of our universe in the first 500 million years of its life.”