NASA Space Telescopes Spot an Early Universe Surprise: A Mature Galaxy Cluster
A new discovery captures the cosmic moment when a galaxy cluster—among the largest structures in the universe—started to assemble only about a billion years after the big bang, one or two billion years earlier than previously thought. This result, made using NASA’s Chandra X-ray Observatory and James Webb Space Telescope, will force astronomers to rethink when and how the first galaxy cluster in the universe formed.
Galaxy clusters contain hundreds or even thousands of individual galaxies immersed in enormous pools of superheated gas, along with large amounts of unseen dark matter. In addition to being the giants of the cosmos, astronomers use galaxy clusters to measure the expansion of the universe and the roles of dark energy and dark matter as well as look into other important cosmic questions.
The newly-discovered object, known as JADES-ID1 for its location in the JWST Advanced Deep Extragalactic Survey, or JADES, has a mass about 20 trillion times that of the sun. Astronomers classify JADES-ID1 as a “protocluster” because they see it as it is undergoing an early, violent phase of formation. (One day, it will turn into a full-fledged galaxy cluster, but not for billions of years.) However, astronomers found JADES-ID1 at a much larger distance—corresponding to a much earlier time in the universe—than they expected to find protoclusters. This creates a mystery.
How could it form so quickly?
This discovery of JADES-1 resets the clock as to when astronomers know this can happen. Before JADES-1, most of the computational models predicted that protoclusters would start forming about 3 billion years after the big bang. In other words, JADES-1 is showing up at least a billion years too early to fit into those theories.
In order to find JADES-ID1, astronomers combined deep observations from Chandra and Webb. By design, the JADES field overlaps with the Chandra Deep Field South, the site of the deepest X-ray observation ever conducted. A discovery like this was only possible when two powerful telescopes like Chandra and Webb stare at the same patch of sky at the limit of their observing capabilities.
Scientists will continue to work on their ideas of how JADES-1 could form so quickly after the big bang. In the meantime, astronomers will continue to use telescopes like Chandra to find more like it and learn all they can about the secrets of galaxy clusters.
Duration: 3 minutes
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