Scientists have made a groundbreaking discovery using the Atacama Large Millimeter/submillimeter Array (ALMA). They detected oxygen in a galaxy that is 13.4 billion years old, which is much older than previously thought to be possible for such heavy elements to form.
The galaxy, called JADES-GS-z14-0, had light traveling from it when the universe was younger than 300 million years old. This challenges current theories about the formation of oxygen in galaxies and suggests that at least two stellar generations may have lived and died inside this galaxy.
ALMA’s sensitivity allowed astronomers to detect a clear signal of oxygen in the galaxy’s light, which is strong enough to be certain it’s real. The array also found no dust continuum at the same position, limiting the dust-to-stellar mass ratio to below 0.2 percent.
This discovery compresses traditional chemical evolution models that predict heavy elements like oxygen should not appear until much later in the universe. It implies a rapid buildup of stars and possibly even more efficient star formation processes than previously thought.
The findings are consistent with the James Webb Space Telescope’s (JWST) observations, which revealed an excess at 7.7 microns, backing up the metallicity estimate. However, faint ultraviolet features suggest that roughly 10 percent of ionizing photons may leak into intergalactic space, a clue to early reionization.
The study challenges current simulations of the early universe and suggests a need for revised theoretical adjustments. It raises questions about whether early galaxies experienced unusually rapid star formation bursts or if our understanding of cooling mechanisms, feedback processes, and dark matter interactions needs to be revised.
Future studies using JWST spectroscopy and ALMA campaigns will aim to capture more data on carbon and nitrogen lines and dust emission to better understand the galaxy’s metal and dust inventory.
Source: https://www.earth.com/news/oxygen-detected-in-most-distant-galaxy-yet-cosmic-dawn-jades-gs-z14-0