Galactic Surprise: James Webb Space Telescope Unveils Hidden Companion Galaxy

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Cornell University astronomers used JWST data to discover a companion galaxy hidden behind the light of a foreground galaxy.

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The companion galaxy is surprisingly mature, having already hosted multiple generations of stars despite being 1.4 billion years old.

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The discovery was made while analyzing the first images of SPT0418-47, one of the brightest dusty, star-forming galaxies in the early universe.

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The foreground galaxy's gravity bent and magnified the light into an Einstein ring, revealing the hidden companion galaxy within it.

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The JWST resolved the companion galaxy clearly, identifying it as a new galaxy gravitationally lensed by the same foreground galaxy.

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The two galaxies are relatively small and less dusty, providing insight into how early galaxies evolved into larger ones.

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The proximity of the two galaxies suggests that they are bound to interact with each other and potentially even merge.

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The astronomers estimated the companion galaxy, labeled SPT0418-SE, to be within 5 kiloparsecs of the ring.

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The mature metallicity of the two galaxies was surprising to the researchers, estimated to be similar to our sun despite their age and mass.

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The astronomers have proposed further JWST observing time to study the ring and its companions and reconcile differences observed between optical and far-infrared spectra.

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