Just days after science operations officially began, the NASA/ESA/Canadian Space Agency’s James Webb Space Telescope propelled astronomers into a realm of early galaxies, previously hidden beyond the reach of all other telescopes. Webb now reveals a very rich universe in which the first galaxies formed look markedly different from the mature galaxies we see around us today.
Researchers have found two exceptionally bright galaxies that existed about 300 and 400 million years after the Big Bang. Its extreme brightness baffles astronomers. Young galaxies are converting gas into stars as quickly as they can and appear compressed into spherical or disk shapes much smaller than our own Milky Way. The beginning of stellar birth may have occurred only 100 million years after the Big Bang, which occurred 13.8 billion years ago.
“Everything we’re seeing is new,” said Tommaso Trio of the University of California, Los Angeles, a co-investigator on one of Webb’s programs. “Webb shows us that there is a very rich universe out there that is beyond what we can imagine.” “The universe has surprised us again. These early galaxies are very unusual in many ways.”
The results are from the GLASS-JWST Early Release Science Web Program (Grism Lens-Amplified Survey), Cosmic Evolution Early Release Science Survey (CEERS). Two papers led by Marco Castellano of the National Institute of Astrophysics in Rome, Italy and Rohan Naidu of the Center for Astrophysics | Harvard, Smithsonian, and MIT in Cambridge, Massachusetts is published in Astrophysical Journal Letters.
In just four days of analysis, the researchers found two exceptionally bright galaxies in the GLASS-JWST images. These galaxies existed about 450 and 350 million years after the Big Bang (with redshifts of about 10.5 and 12.5, respectively), which future spectroscopic measurements using Webb will help confirm.
said Rohan Naidu of the more distant GLASS galaxy, referred to as GLASS-z12, which is thought to date back 350 million years after .the great explosion. The previous record holder is the galaxy GN-z11, which existed 400 million years after the Big Bang (redshift 11.1), and was identified in 2016 by the Hubble Observatory and Keck in the Deep Sky programs.
“Based on all the predictions, we thought we had to search a much larger area of space to find such galaxies,” Castellano said.
“These observations make your head explode. This is a whole new chapter in astronomy. It’s like drillingWhen you suddenly find a lost city or something you didn’t know you had. Paola Santini, fourth author of Castellano et al. GLASS-JWST, it’s amazing.
“While the distances of these early sources still need to be confirmed by spectroscopy, their extreme brightness is a real puzzle, challenging our understanding of galaxy formation,” noted Pascal Ochs of the University of Geneva in Switzerland.
Webb’s observations have led astronomers to a consensus that an unusual number of galaxies in the early universe were much brighter than expected. The researchers say this will make it easier for Webb to find more early galaxies in subsequent deep-sky surveys.
“We nailed something incredibly cool. These galaxies must have started together maybe only 100 million years after the Big Bang. No one expected that Dark Ages “It would have ended much earlier,” said Garth Illingworth of the University of California, Santa Cruz. “The primordial universe would have only been one-hundredth of its current age. It is a fraction of time in the 13.8-billion-year-old universe.”
“Our team was struck by its ability to measure the shapes of these first galaxies; their quiet, orderly disks call into question our understanding of how the first galaxies formed in the crowded, chaotic space of the early universe,” noted Naidoo/Och team member Erica Nelson, of the University of Colorado. This remarkable discovery of CDs at such early times was only possible because Webb’s images were much clearer, in infrared light, than the Hubble images.
“These galaxies are very different from the Milky Way or other large galaxies we see around us today,” Treau said.
Illingworth confirmed that the two bright galaxies these teams found have a lot of light. One option, he said, is that it could have been very massive, with lots of low-mass stars, like later galaxies. Alternatively, it could be much less massive, composed of exceptionally many fewer bright starsknown as Population III stars.
Long theorized, they would be the first stars ever born, blazing at explosively high temperatures and composed of only primordial hydrogen and helium. Only later will stars cook heavier elements in their nuclear fusion furnaces. There are no such superheated primordial stars in the local universe.
“In fact, the most distant source is very compact, and its colors seem to indicate that its stellar population is particularly devoid of heavy elements and could even contain some Population III stars. Only the spectra of the web will tell us about this,” said Adriano Fontana, second author of the book. . Castellano and others. Paper and member of the GLASS-JWST Team.
Provide Webb distance estimates for these two galaxies based on their infrared colorimetry. Ultimately, subsequent spectroscopy measurements showing how light is expanding in the expanding universe will provide independent verification of these cosmological scale measurements.
Marco Castellano et al., Early results from GLASS-JWST. Third. Galaxy candidates at z ∼9–15*, Astrophysical Journal Letters (2022). DOI: 10.3847/2041-8213/ac94d0
Guido Roberts Borsani et al., Early results from GLASS-JWST. I: confirmation of Lensed z ≥ 7 Lyman-break galaxies behind the Abell 2744 cluster with NIRISS, Astrophysical Journal Letters (2022). DOI: 10.3847/2041-8213/ac8e6e
European Space Agency
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