Madrid, 5 (Europe Press)
Finding so-called barred galaxies, similar to our own Milky Way, so early in the universe will require astrophysicists to improve their theories of galaxy evolution.
Before the Hubble Space Telescope, Hubble Space Telescope images had never spotted bands at such early times. In one Hubble image, one galaxy, EGS-23205, is little more than a disc-shaped bubble, but in the corresponding JWST image taken last summer, it’s a beautiful spiral galaxy with a pronounced starbar. Both are shown above.
“I took one look at this data and said, let’s leave everything else out!” said Sharda Joji, a professor of astronomy at the University of Texas at Austin. he said in a statement, describing data from the Cosmic Evolution Early Release Science Survey (CEERS), led by Professor Stephen Finkelstein at the University of Austin.
The team located another barred galaxy, EGS-24268, from about 11 billion years ago, making two more barred galaxies present in time than any previously discovered.
In a paper accepted for publication in The Astrophysical Journal Letters, they highlight these two galaxies and show examples of four other galaxies barred more than 8 billion years ago.
“For this study, we’re looking at a new system where no one has used this kind of data or done this kind of quantitative analysis before,” said Yuchen “Kai” Gu, a graduate student who led the analysis. “So everything is new. It’s like going to a forest no one has ever been to before.”
Bars play an important role in the evolution of galaxies by pumping gas into the central regions, leading to star formation.
“Rails solve the galactic supply chain problem,” Jogee said. “Just as we need to ferry raw materials from the port to the inland factories that make new products, a rod ferociously carries gas into the Midwest, where gas is rapidly turning into new stars 10 to 100 times faster than it is in the rest of the galaxy.” The rods also help the growth of supermassive black holes in the centers of galaxies by diverting gas part of the way.
The discovery of bars at such early times 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 get the galactic physics right to predict the correct abundance of bars. The team will test different models in their next articles.
JWST can detect 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 watches 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, helping narrow the list down to a few dozen so other researchers could analyze it with more intensive calculations. Approaching.
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