AUSTIN, Texas — New images from NASA’s James Webb Space Telescope (JWST) reveal for the first time bargalaxies — elongated features of stars that extend from the centers of galaxies to their outer disks — at a time when the universe was a mere 25% of its present age. The discovery of so-called barred galaxies, similar to our own Milky Way, this early in the universe will require astrophysicists to improve their theories of galaxy evolution.
Before JWST, images from the Hubble Space Telescope had never spotted bands at such young ages. In the Hubble image, one galaxy, EGS-23205, is little more than a disc-shaped smudge, but in the corresponding JWST image taken last summer, it’s a beautiful spiral galaxy with a pronounced starbar.
“I took one look at this data, and I said, ‘We’re dropping everything else! she said, describing data from the Scientific Early Evolution Survey (CEERS) led by UT Austin Professor Stephen Finkelstein.
The team located another galaxy, EGS-24268, from about 11 billion years ago, which makes two bound galaxies that coexist farther back than any previously discovered.
In an article accepted for publication in Astrophysical Journal LettersThey highlight these two galaxies and show examples of four other galaxies that were banned more than 8 billion years ago.
“For this study, we’re looking at a new system in which no one has used this type of data or conducted this type of quantitative analysis before,” said Yuxin “Kai” Gu, the graduate student who led the analysis. the new. It’s like going to a forest no one has been to before.”
Bars play an important role in the evolution of galaxies by pumping gas into the central regions, which promotes star formation.
“Rails solve the galactic supply chain problem,” Jogee said. “Just as we need to bring raw materials from the harbor to the inland factories that make new products, a rod vigorously transports gas to the central region where the gas is rapidly converted into new stars at a rate typically 10 to 100 times faster than in the rest of the galaxy.”
The bars also help the formation of supermassive black holes in the centers of galaxies by directing the gas part of the way.
The discovery of bars during these early ages has shaken up scenarios of galaxy evolution in several ways.
“This early detection of the bars means that models of galaxy evolution now have a new path through the bars to accelerate the production of new stars at early ages,” Jogee said.
And the existence of these early bars challenges theoretical models because they need to correct for galactic physics in order to predict the correct abundance of bars. The team will test different models in their upcoming papers.
JWST can reveal structures in distant galaxies better than Hubble for two reasons: First, its larger mirror gives it greater light-gathering ability, allowing it to see farther and with higher resolution. Second, it can see through the dust better because it observes at longer infrared wavelengths than the Hubble telescope.
Undergraduates Eden Wise and Zilei Chen played a major role in the research by visually reviewing hundreds of galaxies, looking for those that appeared to have bars, which helped narrow the list down to a few dozen so that other researchers could analyze it with more intensive calculations. Approaching.
Other co-authors from the University of Austin are Stephen Finkelstein, Michaela Bagley, and Maximilian Franco. Dozens of co-authors from other institutions hail from the United States, the United Kingdom, Japan, Spain, France, Italy, Australia, and Israel.
Funding for this research was provided in part by the Roland K. Blumberg Endowment in Astronomy, the Heising-Simons Foundation and NASA. This work drew on resources at the Texas Center for Advanced Computing, including Frontera, the most powerful supercomputer at an American university.