A team using NASA’s James Webb Space Telescope has observed two of the most distant galaxies astronomers have ever seen. These distant regions, nearly 33 billion light-years from Earth, could provide insight into how the universe’s oldest galaxies formed. For more information on the survey results, please visit The study was published on November 13th Astrophysics Journal Letter.
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The UNCOVER z-13 and UNCOVER z-12 galaxies are the second and fourth most distant galaxies ever observed, and are located in a region called the Pandora cluster (Abell 2744). The two galaxies are among her 60,000 light sources in the Pandora galaxy cluster captured by JWST as part of his first deep-field images of 2022. This region of space was chosen for this type of imaging because it lies behind several galaxy clusters. Light creates a natural magnifying effect called gravitational lensing. This happens when the gravitational force of the cluster’s combined mass distorts spacetime around it. It then magnifies the light passing nearby, providing a wide field of view behind the cluster.
Other galaxies at this distance have also been identified. Usually appears as a red dot in images. But the researchers say these new galaxies are larger, resembling peanuts or fluffy balls.
“We know very little about the early Universe. The only way to learn more about it and test our theories about the formation and growth of early galaxies is to study these very distant galaxies.” said study co-author Binji Wang, an astronomer at Pennsylvania State University. stated in a statement. “Prior to our analysis, only three galaxies had been identified near such extreme distances. By studying these new galaxies and their properties, we will be able to explore the diversity of galaxies in the early Universe and It became clear how much we had to learn from that.”
Wang is also a member. JWST UNCOVER The (pre-reionization era Ultradeep NIRSpec and NIRCam ObserVations) teams that conducted this study. UNCOVER’s initial goal is to use JWST to obtain highly detailed images of the region around the Pandora star cluster.
The light emitted by these galaxies required a long journey to reach Earth, providing a window into the universe’s past. The research team estimates that the light detected by JWST was emitted by two galaxies when the universe was around 330 million years old, and took about 13.4 billion light years to reach the space telescope.
However, due to the expansion of the universe during this period, the galaxy is now nearly 33 billion light-years away from Earth.
“The light from these galaxies is ancient, about three times older than Earth,” says study co-author Joel Reja, a Penn State astronomer and UNCOVER member. stated in a statement. “These early galaxies are like lighthouses, with light shooting out through the very thin hydrogen gas that made up the early universe. Only by their light could the eccentricities that dominated galaxies near the dawn of the universe You can start to understand the physics.”
[Related: JWST takes a jab at the mystery of the universe’s expansion rate.]
These two galaxies are significantly larger than the three previously located at such extreme distances. Our Milky Way galaxy has a diameter of about 100,000 light years. Galaxies in the early universe are thought to have been highly compressed. The research team’s image of a galaxy 2,000 light-years in diameter similar to one of his was a surprise.
“Galaxies discovered so far at these distances are point sources and appear as points in our images,” Wang said. “But one of ours looks elongated, almost like a peanut, and the other looks like a fluffy ball. The difference in size may explain how the star formed, or if it’s a star. It is unknown what happened after they formed, but the diversity of galaxies’ properties is very interesting. Although these early galaxies are expected to have formed from similar material, they already show signs of being very different from each other. It shows.”
To make inferences about these early galaxies, the research team used detailed models. They believe that in addition to being young (by cosmic standards), the two galaxies have very little metal in their composition, are growing rapidly, and are actively forming stars. Ta.
“The first elements were created in the centers of early stars through the process of nuclear fusion,” Reya said. “It’s no surprise that heavy elements like metals aren’t present in these early galaxies, because they were some of the first factories that produced those heavy elements. And of course, the first Although they need to be young and star-forming to become galaxies, confirming these properties is an important fundamental test of our model and helps confirm the entire Big Bang theory paradigm. .”
Astronomers will continue to use the Lens Cluster and instruments aboard JWST to trace back the timeline of some of the universe’s earliest galaxies.