Astronomers have made a groundbreaking discovery with the James Webb Space Telescope (JWST), uncovering the oldest known “dead” galaxy. This finding challenges current models of the early universe and provides new insights into galactic evolution.
The galaxy, named JADES-GS-z7-01-QU, ceased star formation over 13 billion years ago when the universe was a mere 700 million years old. This sudden halt in star formation has left astronomers puzzled because, at that time, the universe was abundant with the necessary dust and gas for star formation.
“The first few hundred million years of the universe was a very active phase, with lots of gas clouds collapsing to form new stars,” explains Tobias Looser, lead author of the study from the University of Cambridge. “Galaxies need a rich supply of gas to form new stars, and the early universe was like an all-you-can-eat buffet.”
Data from the JWST Advanced Deep Survey (JADES) reveals that the galaxy likely experienced a brief burst of star formation lasting between 30 to 90 million years. However, this burst abruptly ended between 10 to 20 million years before the JWST observed it.
While dead galaxies that no longer form stars have been observed in the early universe before, JADES-GS-z7-01-QU is the oldest recorded galaxy of its kind, appearing only 700 million years after the Big Bang. Additionally, it is much smaller than previously observed dormant galaxies, thanks to the JWST’s improved sensitivity in detecting fainter and smaller galaxies.
Roberto Maiolino, co-author of the study from the University of Cambridge, highlights the significance of this discovery. “Until now, to understand the early universe, we’ve used models based on the modern universe,” he says. “But now that we can see so much further back in time and observe that star formation was quenched so rapidly in this galaxy, models based on the modern universe may need to be revisited.”
The recent observations of JADES-GS-z7-01-QU represent the deepest views into the distant universe ever made by the JWST. The rapid burst of star formation observed in the galaxy may have depleted its reservoir of dust and gas, halting any further star formation.
“Everything seems to happen faster and more dramatically in the early universe, and that might include galaxies moving from a star-forming phase to dormant or quenched,” says Looser.
As astronomers continue to unravel the mysteries of this ancient galaxy, they plan to search for more old galaxies to gain a better understanding of galactic evolution during the early universe. These findings will contribute to the development of more accurate models for that time period.
The study detailing these findings was published on March 6 in the journal Nature. This groundbreaking discovery opens up new avenues for exploration and challenges our understanding of the early universe. With each new observation, astronomers are piecing together the puzzle of our cosmic origins.