Oxygen discovered in most distant known galaxy

Press Release

20 March 2025

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.

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.

“It is like finding an adolescent where you would only expect babies,” says Sander Schouws, a PhD candidate at Leiden Observatory, the Netherlands, and first author of the Dutch-led study, now accepted for publication in The Astrophysical Journal. “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.”

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 10 times more heavy elements than expected.

“I was astonished by the unexpected results because they opened a new view on the first phases of galaxy evolution,” says Stefano Carniani, of the Scuola Normale Superiore of Pisa, Italy, and lead author on the paper now accepted for publication in Astronomy & Astrophysics. “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,” adds Eleonora Parlanti, a PhD student at the Scuola Normale Superiore of Pisa and author on the Astronomy & Astrophysics study [1].

“While the galaxy was originally discovered with the James Webb Space Telescope, it took ALMA to confirm and precisely determine its enormous distance,” [2] says 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.”

Gergö Popping, an ESO astronomer at the European ALMA Regional Centre who did not take part in the studies, says: “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 unraveling the conditions under which the first galaxies in our Universe formed.”

Notes

[1] Astronomers use a measurement known as redshift to determine the distance to extremely distant objects. Previous measurements indicated that the galaxy JADES-GS-z-14-0 was at a redshift between about 14.12 and 14.4. With their oxygen detections, both teams have now narrowed this down to a redshift around 14.18.

[2] The James Webb Space Telescope is a joint project of NASA, the European Space Agency (ESA) and the Canadian Space Agency (CSA).

More information

This research was presented in two papers to appear in Astronomy & Astrophysics (https://aanda.org/10.1051/0004-6361/202452451) and The Astrophysical Journal.

The teams are composed of:

Italian-led, Astronomy & Astrophysics paper: Stefano Carniani (Scuola Normale Superiore, Pisa, Italy [SNS]), Francesco D’Eugenio (Kavli Institute for Cosmology, University of Cambridge, Cambridge, UK [CAM-KIC]; Cavendish Laboratory, University of Cambridge, Cambridge, UK [CAM-CavL] and INAF – Osservatorio Astronomico di Brera, Milano, Italy), Xihan Ji (CAM-KIC and CAM-CavL), Eleonora Parlanti (SNS), Jan Scholtz (CAM-KIC and CAM-CavL), Fengwu Sun (Center for Astrophysics | Harvard & Smithsonian, Cambridge, USA [CfA]), Giacomo Venturi (SNS), Tom J. L. C. Bakx (Department of Space, Earth, & Environment, Chalmers University of Technology, Gothenburg, Sweden), Mirko Curti (European Southern Observatory, Garching bei München, Germany), Roberto Maiolino (CAM-KIC, CAM-CavL and Department of Physics and Astronomy, University College London, London, UK [UCL]), Sandro Tacchella (CAM-KIC and CAM-CavL), Jorge A. Zavala (National Astronomical Observatory of Japan, Tokyo, Japan), Kevin Hainline (Steward Observatory, University of Arizona, Tucson, USA [UArizona-SO]), Joris Witstok (Cosmic Dawn Center, Copenhagen, Denmark [DAWN] and CAM-CavL), Benjamin D. Johnson [CfA], Stacey Alberts [UArizona-SO], Andrew J. Bunker (Department of Physics, University of Oxford, Oxford, UK [Oxford]), Stéphane Charlot (Sorbonne Université, CNRS, Institut d’Astrophysique de Paris, Paris, France), Daniel J. Eisenstein (CfA), Jakob M. Helton (UArizona-SO), Peter Jakobsen (DAWN and Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark), Nimisha Kumari (Space Telescope Science Institute, Baltimore, USA), Brant Robertson (Department of Astronomy and Astrophysics University of California, Santa Cruz, USA), Aayush Saxena (Oxford and UCL), Hannah Übler (CAM-KIC and CAM-CavL), Christina C. Williams (NSF NOIRLab, Tucson, USA), Christopher N. A. Willmer (UArizona-SO) and Chris Willott (NRC Herzberg, Victoria, Canada).

Dutch-led, The Astrophysical Journal paper: Sander Schouws (Leiden Observatory, Leiden University, Leiden, the Netherlands [Leiden]), Rychard J. Bouwens (Leiden), Katherine Ormerod (Astrophysics Research Institute, Liverpool John Moores University, Liverpool, United Kingdom [LJMU]), Renske Smit (LJMU), Hiddo Algera (Hiroshima Astrophysical Science Center, Hiroshima University, Hiroshima, Japan and National Astronomical Observatory of Japan, Tokyo, Japan), Laura Sommovigo (Center for Computational Astrophysics, Flatiron Institute, New York, USA), Jacqueline Hodge (Leiden), Andrea Ferrara (Scuola Normale Superiore, Pisa, Italy), Pascal A. Oesch (Département d’Astronomie, Université de Genève, Versoix, Switzerland; Cosmic Dawn Center, Copenhagen, Denmark and Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark), Lucie E. Rowland (Leiden), Ivana van Leeuwen (Leiden), Mauro Stefanon (Leiden), Thomas Herard-Demanche (Leiden), Yoshinobu Fudamoto (Center for Frontier Science, Chiba University, Chiba, Japan), Huub Rottgering (Leiden) and Paul van der Werf (Leiden).

The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of ESO, the U.S. National Science Foundation (NSF) and the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Republic of Chile. ALMA is funded by ESO on behalf of its Member States, by NSF in cooperation with the National Research Council of Canada (NRC) and the National Science and Technology Council (NSTC) in Taiwan and by NINS in cooperation with the Academia Sinica (AS) in Taiwan and the Korea Astronomy and Space Science Institute (KASI). ALMA construction and operations are led by ESO on behalf of its Member States; by the National Radio Astronomy Observatory (NRAO), managed by Associated Universities, Inc. (AUI), on behalf of North America; and by the National Astronomical Observatory of Japan (NAOJ) on behalf of East Asia. The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

The European Southern Observatory (ESO) enables scientists worldwide to discover the secrets of the Universe for the benefit of all. We design, build and operate world-class observatories on the ground — which astronomers use to tackle exciting questions and spread the fascination of astronomy — and promote international collaboration for astronomy. Established as an intergovernmental organisation in 1962, today ESO is supported by 16 Member States (Austria, Belgium, Czechia, Denmark, France, Finland, Germany, Ireland, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom), along with the host state of Chile and with Australia as a Strategic Partner. ESO’s headquarters and its visitor centre and planetarium, the ESO Supernova, are located close to Munich in Germany, while the Chilean Atacama Desert, a marvellous place with unique conditions to observe the sky, hosts our telescopes. ESO operates three observing sites: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope and its Very Large Telescope Interferometer, as well as survey telescopes such as VISTA. Also at Paranal ESO will host and operate the Cherenkov Telescope Array South, the world’s largest and most sensitive gamma-ray observatory. Together with international partners, ESO operates ALMA on Chajnantor, a facility that observes the skies in the millimetre and submillimetre range. At Cerro Armazones, near Paranal, we are building “the world’s biggest eye on the sky” — ESO’s Extremely Large Telescope. From our offices in Santiago, Chile we support our operations in the country and engage with Chilean partners and society.