This is an artist’s impression of JADES-GS-z14-0, which as of today is the most distant confirmed galaxy. Galaxies in the early Universe tend to be clumpy and irregular. Supernova explosions in this galaxy would have spread heavy elements forged inside stars, like oxygen, which has been now detected with the Atacama Large Millimeter/submillimeter Array (ALMA). Credit: ESO/ M Kornmesser.

Two different teams of astronomers have detected oxygen in the most distant known galaxy, JADES-GS-z14-0.

The discovery, reported in two separate studies, was made possible thanks to the Atacama Large Millimeter/ submillimeter Array (ALMA), in which the European Southern Observatory (ESO) is a partner.

This record-breaking detection is making astronomers rethink how quickly galaxies formed in the early Universe.

Discovery

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.

First author of the Dutch-led study, Sander Schouws, who is a PhD candidate at Leiden Observatory, the Netherlands, said: “It is like finding an adolescent where you would only expect babies.

“The results show the galaxy has formed very rapidly and is also maturing rapidly, adding to a growing body of evidence that the formation of galaxies happens much faster than was expected.” 

This image shows the precise location in the night sky of the galaxy JADES-GS-z14-0, an extremely tiny dot in the Fornax constellation. As of today, this is the most distant confirmed galaxy we know of. Its light took 13.4 billion years to reach us and shows the conditions of the Universe when it was only 300 million years old. The inset of the image shows a close-up of this primordial galaxy as seen with the Atacama Large Millimeter/submillimeter Array. The inset is overlaid on an image taken with the NASA/ESA/CSA James Webb Space Telescope.

When two research teams studied this galaxy with ALMA, operated by ESO and its international partners, they uncovered something unexpected: the spectrum of the galaxy indicated the presence of oxygen. This is the most distant detection of oxygen ever, and it defies what we knew about galaxy formation in the early Universe. The presence of heavy elements like oxygen suggest that these early galaxies evolved more rapidly than we thought. It is like finding an adolescent where you would only expect babies. Credit: ALMA (ESO/ NAOJ/ NRAO)/ S Carniani et al/ S Schouws et al/ JWST: NASA, ESA, CSA, STScI, Brant Robertson (UC Santa Cruz), Ben Johnson (CfA), Sandro Tacchella (Cambridge), Phill Cargile (CfA).

Heavy elements

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, the two ALMA studies indicate JADES-GS-z14-0 has about ten times more heavy elements than expected.

Lead author of the Italian-led paper, Stefano Carniani, of the Scuola Normale Superiore of Pisa, Italy, said: “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.

Eleonora Parlanti, a PhD student at the Scuola Normale Superiore of Pisa, added: “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 5cm over a distance of 1km — helps refine our understanding of distant galaxy properties.

Amazing synergy

Associate Professor Rychard Bouwens, a member of the team at Leiden Observatory, said: “While the galaxy was originally discovered with the James Webb Space Telescope, it took ALMA to confirm and precisely determine its enormous distance.

“This shows the amazing synergy between ALMA and JWST to reveal the formation and evolution of the first galaxies.”

Gergö Popping, an ESO astronomer at the European ALMA Regional Centre who did not take part in the studies, said: “I was really surprised by this clear detection of oxygen in JADES-GS-z14-0.

“It suggests galaxies can form more rapidly after the Big Bang than had previously been thought.

“This result showcases the important role ALMA plays in unravelling the conditions under which the first galaxies in our Universe formed.”

The Dutch-led and Italian-led studies are published in The Astrophysical Journal and Astronomy & Astrophysics, respectively.