Oxygen Detected in Ancient Galaxy

Astronomers report oxygen in the most distant known galaxy, suggesting rapid chemical enrichment just 300 million years after the Big Bang.

Oxygen Found in Galaxy from Dawn of Time

Astronomers have detected the 88 micron oxygen line in the galaxy JADES-GS-z14-0, using ALMA with support from JWST. The galaxy is about 13.4 billion light-years away, placing its light roughly 300 million years after the Big Bang. The gas has a metallicity around one fifth that of the Sun, indicating at least two generations of stars had already lived and died. Dust is scarce, with a dust-to-stellar mass ratio below 0.2 percent, pointing to fast, efficient star formation in the early universe.

The ionized gas in the galaxy moves at about 70 kilometers per second, implying a dynamical mass near one billion solar masses and a substantial dark matter halo. A signal excess at 7.7 microns aligns with strong hydrogen and oxygen emissions and hints that some ionizing photons may be escaping into intergalactic space, potentially contributing to reionization. Future JWST spectroscopy will search for carbon and nitrogen, while higher frequency ALMA data aim to detect faint dust emission and refine our picture of early metal production.

This finding challenges the idea that heavy elements appeared slowly in the early cosmos. It suggests either faster bursts of star formation or more efficient mixing of supernova debris than current models allow. The result adds to a growing sense that early galaxies could grow rapidly and be more complex than once thought.

If more galaxies from this epoch show similar oxygen signatures, theorists will need to rethink how and when massive stars enrich their surroundings and how dark matter halos form and stabilize these early systems. Yet the evidence is still one galaxy and a select sample; broader observations will determine whether JADES-GS-z14-0 is typical or an outlier.

Highlights

The universe keeps surprising us with how fast it can grow up.