The existence of the second and fourth most distant galaxies ever recorded (UNCOVER z-13 and UNCOVER z-12) has been confirmed using the James Webb Space Telescope’s near infrared camera (NIRCam). These galaxies are located in the Pandora cluster (Abell 2744), and are shown here as wavelengths of near-infrared light translated into visible light colors. The main cluster image is scaled in arcseconds, which is a measure of angular distance in the sky. The circle in the black-and-white image, which shows galaxies in the range of the NIRCam-F277W filter on the James Webb Telescope, shows an aperture size of 0.32 arcseconds. Source: Cluster image: NASA, UNCOVER (Bezanson et al., DIO: 10.48550/arXiv.2212.04026) Insert: NASA, UNCOVER (Wang et al., 2023) Synthesis: Danny Ziemba/Penn State
Subsequent observations of the Pandora cluster confirmed the existence of the second and fourth most distant galaxies ever, larger than any other galaxy found at such extreme distances.
The second and fourth most distant galaxies ever discovered were discovered in a region of space known as the Pandora cluster, or Abell 2744, using data from… NASA’S James Webb Space Telescope (JWST). In a follow-up image of the region (see image below), an international team led by Penn State researchers confirmed the distances of these ancient galaxies and deduced their properties using new spectroscopic data – information about the light emitted across the electromagnetic spectrum – from JWST. Some 33 billion light years away, these very distant galaxies provide a glimpse into how the first galaxies formed.
Unique appearance and significance
Unlike other confirmed galaxies at this distance, which appear in images as red dots, this new galaxy is larger and looks like a fuzzy bean and ball, according to the researchers. A paper describing the galaxy appeared today (November 13) in the journal Astrophysical Journal Letters.
Astronomers estimate there are 50,000 near-infrared light sources represented in field images in the Pandora cluster from NASA’s James Webb Space Telescope. The light travels different distances to reach the telescope detector, representing the vastness of space in one image. Credits: Science: NASA, ESA, CSA, Ivo Lappé (Swinburne), Rachel Bezanson (University of Pittsburgh), Image processing: Alyssa Pagan (STScI)
“Very little is known about the early universe, and the only way to study that time and test our theories about galaxy formation and early growth is through these very distant galaxies,” said first author Bingyi Wang, a postdoctoral researcher at the University of Pennsylvania. Eberly State College of Science and member JWST UNCOVER Team (NIRSpec and NIRCam Ultradeep Observations before the reionization era) who conducted the research. “Prior to our analysis, we only knew of three galaxies confirmed to be at this extreme distance. Studying these new galaxies and their properties has revealed the diversity of galaxies in the early universe and how much there is to learn from them.”
Insights into the early universe
Because the light from these galaxies has to travel a long way to reach Earth, this provides a window into the past. The research team estimates that the light discovered by the James Webb Space Telescope was emitted from the two galaxies when the universe was about 330 million years old, and traveled about 13.4 billion light years to reach the James Webb Space Telescope. But the researchers say that these galaxies are now closer to 33 billion light years from Earth due to the expansion of the universe during that period.
“The light from these galaxies is ancient, about three times older than Earth’s,” said Joel Lyja, assistant professor of astronomy and astrophysics at Penn State and a member of UNCOVER. “These early galaxies were like lighthouses, light shining through the very thin hydrogen gas that made up the early universe. Only through their light can we begin to understand the strange physics that govern galaxies on the eve of the cosmic dawn.”
Using the James Webb Space Telescope, scientists have discovered two distant galaxies in the Pandora cluster, providing new insight into the early universe. These galaxies, with their unique size and appearance, challenge our understanding of galaxy formation in the early universe. Credit: NASA
It should be noted that these two galaxies are much larger than the three galaxies that existed previously at such a great distance. One of them is at least six times larger and about 2,000 light years across. For comparison, the Milky Way galaxy is about 100,000 light years across, but Wang believes the early universe was very compact, so it would be surprising if this galaxy could be that big.
“The galaxies previously discovered at this distance are point sources. They appear as a dot in our image,” Wang said. “But one of our stars looks elongated, almost like a bean, and the other looks like a thin ball. It’s not clear whether these size differences are due to how the stars form or what happens to the stars after they form, but the diversity in the properties of galaxies is fascinating. These early galaxies are thought to have formed from similar materials, but they already show signs of being very different from each other.
Research methodology
The two galaxies were among 60,000 light sources in the Pandora cluster discovered in one of the first deep-field images taken by the James Webb Space Telescope in 2022, its first year of science operations. This region of space was chosen because it lies behind many galaxy clusters which creates a natural magnification effect called gravitational lensing. The gravitational force of the cluster’s combined mass distorts the space around it, focusing and amplifying any light that passes nearby and providing a greater view behind the cluster.
Within months, the UNCOVER team narrowed down 60,000 light sources to 700 candidates for follow-up study, eight of which they believe were the first galaxies. Later, the James Webb Space Telescope again pointed at the Pandora cluster, recording a candidate spectrum, a kind of fingerprint detailing the amount of light emitted at each wavelength.
“Several different teams used different methods to search for these ancient galaxies, each with their own strengths and weaknesses,” Leija said. “The fact that we point this giant magnifying glass into space gives us a window of great depth, but the window is so small that we roll the dice. Many of the candidates are unconvincing, and at least one of them is a case of mistaken identity. It is something much closer.” “It simulates a distant galaxy. But we were lucky, and two of them turned out to be ancient galaxies. Truly extraordinary.”
Properties and effects
The researchers also used detailed models to infer the properties of these early galaxies when they emitted the light detected by the James Webb Space Telescope. As the researchers expected, both galaxies are young, have little metal in their composition, are growing rapidly, and are actively forming stars.
“The first elements were formed in the cores of early stars through the fusion process,” Lyga said. “It makes sense that these early galaxies did not have heavy elements such as metals because they were among the first factories to make these heavy elements. Of course, they had to be young and form stars to become the first galaxies, but confirming these properties is an important fundamental test of our model and helps in confirming the complete galaxy model. the big bang is a theory.”
Combined with gravitational lensing, the James Webb Space Telescope’s powerful infrared instruments should be able to detect galaxies at much greater distances, if they exist, the researchers said.
“We have a very small window into this region, and we don’t observe anything outside these two galaxies, even though the James Webb Space Telescope has that capability,” Leja said. “This may mean that galaxies had not formed before that time, and we would not find anything further away. Or it might also mean that we are not lucky enough because our window is small.”
This work is the result of a successful proposal submitted to NASA proposing how the James Webb Space Telescope could be used during its first year of science operations. In the first three rounds of submissions, NASA received four to ten times as many proposals as observing time available through the telescope, and only had to select a portion of them.
“Our team was very excited and a little surprised when our proposal was accepted,” said Leija. “This involved coordination, fast human action, and pointing the telescope at the same object twice, which was a big demand for the telescope in its first year. There was a lot of pressure because we only had a few months to decide what things to do.” But the James Webb Space Telescope was created and attempted to discover these first galaxies, and it’s very exciting to do so now.
Reference: “Detection: Explaining the Early Universe — JWST/NIRSpec Confirmation of a z>12 Galaxy” by Benjie Wang, 冰洁王, Seiji Fujimoto, Ivo Lappé, Lukas J. Furtak, Tim B. Miller, David J. Seaton, Adi Zittrain, Hakim Atiq, Rachel Besançon, Gabriel Brammer, Joel Leja, Pascal A. Osch, Sedona H. Price, Irina Chemerinska, Sam E. Cutler, Pratika Dayal, Peter van Dokkum, Andy de Golding, Jenny E. Green, Y. . Vodamoto, Gaurav Khullar, Vasiliy Kokorev, Danilo Marchesini, Richard Pan, John R. Weaver, Katherine E. Whittaker and Christina C. Williams, 13 November 2023, Astrophysical Journal Letters.
two: 10.3847/2041-8213/acfe07
In addition to Penn State, the team also includes researchers from the University of Texas at Austin, Swinburne University of Technology in Australia, Ben Gurion University of the Negev in Israel, and Ben Gurion University of the Negev in Israel. Yale University, University of Pittsburgh, Sorbonne University in France, University of Copenhagen in Denmark, University of Geneva in Switzerland, University of Massachusetts, University of Groningen in the Netherlands, Princeton University, Waseda University in Japan, Tufts University, and the National Laboratory for Optical and Infrared Astronomy Research (NOIR).
This work was supported by NASA, the US-Israel Bi-Science Foundation, the US National Science Foundation, the Israeli Ministry of Science and Technology, the French National Center for Space Studies, the French National Institute of Geosciences and Astronomy, and the Central Research Institute. Foundation for the Advancement of Science, Netherlands Research Council, European Commission and University of Groningen in joint funding of the Rosalind Franklin Program, National Astronomical Observatory of Japan and NOIR Laboratory.
2023-11-14 06:45:31
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