Two different teams of astronomers have detected oxygen in the most distant known galaxy, JADES-GS-z14-0.
Discovered last year, JADES-GS-z14-0 is the most distant confirmed galaxy ever found: it is so far away, its light took 13.4 billion years to reach us, meaning we see it as it was when the Universe was less than 300 million years old, about 2% of its present age. The new oxygen detection with ALMA, a telescope array in Chile’s Atacama Desert, suggests the galaxy is much more chemically mature than expected.
Galaxies usually start their lives full of young stars, which are made mostly of light elements like hydrogen and helium. As stars evolve, they create heavier elements like oxygen, which get dispersed through their host galaxy after they die. Researchers had thought that, at 300 million years old, the Universe was still too young to have galaxies ripe with heavy elements. However, two ALMA studies indicate JADES-GS-z14-0 has about 10 times more heavy elements than expected.
Stefano Carniani, of the Scuola Normale Superiore of Pisa, Italy, explained:
“I was astonished by the unexpected results because they opened a new view on the first phases of galaxy evolution. The evidence that a galaxy is already mature in the infant Universe raises questions about when and how galaxies formed.”
The oxygen detection has also allowed astronomers to make their distance measurements to JADES-GS-z14-0 much more accurate.
“The ALMA detection offers an extraordinarily precise measurement of the galaxy’s distance down to an uncertainty of just 0.005 percent. This level of precision — analogous to being accurate within 5 cm over a distance of 1 km — helps refine our understanding of distant galaxy properties,” said Eleonora Parlanti, a PhD student at the Scuola Normale Superiore of Pisa.
“While the galaxy was originally discovered with the James Webb Space Telescope, it took ALMA to confirm and precisely determine its enormous distance,” added Associate Professor Rychard Bouwens, a member of the team at Leiden Observatory. “This shows the amazing synergy between ALMA and JWST to reveal the formation and evolution of the first galaxies.”
The two research papers have been published in Astronomy and Astrophysics:
The eventful life of a luminous galaxy at z = 14: metal enrichment,
feedback, and low gas fraction?
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