If you could rewind the universe to its first billion years and freeze the frame, what would the very first galaxies look like? A new discovery suggests they were anything but simple and smooth.<\/p>\n\n\n\n
Astronomers using the James Webb Space Telescope (JWST)<\/a> and the Atacama Large Millimeter or submillimeter Array (ALMA)<\/a> have found a young rotating galaxy, nicknamed \u201cthe Cosmic Grapes<\/a>,\u201d that lived only about 900 million years after the Big Bang. <\/p>\n\n\n\n Instead of a gentle disk of stars, it is packed with at least 15 dense, bright star-forming clumps that bunch together like a cluster of fruit. That crowded structure goes beyond what leading computer models said should be possible in a single early galaxy.<\/p>\n\n\n\n The team could see this surprising level of detail only because nature helped. A massive foreground cluster of galaxies<\/a> bends space around it and acts as a kind of cosmic magnifying glass. This effect, called gravitational lensing<\/a>, stretches and brightens the light from the distant system so that ALMA and JWST can zoom in far beyond their usual limits. <\/p>\n\n\n\n One of the study\u2019s authors describes the galaxy as \u201cone of the most strongly gravitationally-lensed distant galaxies ever discovered,\u201d which turned it into a rare laboratory for testing theories of how galaxies grow.<\/p>\n\n\n\n More than one hundred hours of observing time<\/a> went into this single object. With that patience, astronomers were able to map both the cold gas that fuels star formation and the young stars themselves. <\/p>\n\n\n\n They found a rotating disk that looks, in broad strokes, like a normal star forming galaxy. Yet inside that disk sit compact clumps only a few tens of light years across, each with very high gas density. According to the researchers, \u201cthese clumps are massive and have high gas densities, conditions that are conducive to forming stars very efficiently.\u201d<\/p>\n\n\n\n In everyday terms, it is a little like flying over a city at night and realizing that most of the light comes from a handful of intensely lit neighborhoods instead of being spread evenly across town. In the Cosmic Grapes, several small regions dominate the glow of young stars. That pattern hints that early galaxies<\/a> may have grown through many compact bursts of star formation rather than through a single smooth wave.<\/p>\n\n\n\n What really puzzles theorists is the number of clumps. State-of-the-art simulations of the young universe<\/a> do produce unstable disks that fragment into a few dense knots. They do not usually produce a rotating system that holds more than a dozen such clumps at once, especially at such an early cosmic time. <\/p>\n\n\n\n The new observations suggest that key ingredients in these models, such as how exploding stars stir and heat gas or how fast material can cool and collapse again, may need to be revisited. As the ALMA team notes, this galaxy \u201craises key questions about how galaxies form and evolve\u201d in the first billion years.<\/p>\n\n\n\nGravitational lensing and cosmic magnification<\/h2>\n\n\n\n
Star forming clumps in a young rotating galaxy<\/h2>\n\n\n\n
Read More: NASA observes China from space and discovers a giant structure hidden in plain sight that not even an entire forest has managed to conceal from the crater<\/a><\/h3>\n<\/div>\n<\/div><\/div>\n<\/div>\n\n\n\n
Early universe simulations and clumpy galaxy disks<\/h2>\n\n\n\n