ON THE ORIGINS OF OXYGEN: ALMA AND JWST CHARACTERISE THE MULTI-PHASE, METAL-ENRICHED, STAR-BURSTING MEDIUM WITHIN A ‘NORMAL’ z > 11 GALAXY
Journal article, 2026
The unexpectedly high abundance of galaxies at z > 11 revealed by JWST has sparked a debate on the nature of early galaxies and the physical mechanisms regulating their formation. The Atacama Large Millimeter/submillimeter Array (ALMA) has begun to provide vital insights on their gas and dust content, but so far only for extreme ‘blue monsters’. Here we present new, deep ALMA observations of JADES-GS-z11-0, a more typical (sub-L∗ ) z > 11 galaxy that bridges the discovery space of JWST and the Hubble Space Telescope. These data confirm the presence of the [O iii] 88 µm line at 4.5σ significance, precisely at the redshift of several faint emission lines previously seen with JWST/NIRSpec, while the underlying dust continuum remains undetected (Fν < 9.0 µJy), implying an obscured star formation rate (SFR) of SFRIR ≲ 6 M⊙ yr−1 and dust mass of Mdust ≲ 1.0 × 106 M⊙(all 3σ). The accurate ALMA redshift of z[O iii] = 11.1221 ± 0.0006 (≳ 5× refined over NIRSpec) helps confirm that redshifts measured purely from the Lyman-α break, even spectroscopically, should properly take into account the effects of potential damped Lyman-α (DLA) absorption to avoid systematic overestimates of up to ∆z ≈ 0.5. The [O iii] 88 µm luminosity of L[O iii] = (1.1 ± 0.3) × 108 L⊙, meanwhile, agrees well with the scaling relation for local metal-poor dwarfs given the SFR measured by NIRCam, NIRSpec, and MIRI. The spatially resolved MIRI and ALMA emission also underscores that JADES-GS-z11-0 is likely to consist of two low-mass components that are undergoing strong bursts of star formation yet are already pre-enriched in oxygen (∼ 20-30% solar), only 400 Myr after the Big Bang.
Author
Joris Witstok
Niels Bohr Institute
Cosmic Dawn Center (DAWN)
Renske Smit
Liverpool John Moores University
William M. Baker
Niels Bohr Institute
Pierluigi Rinaldi
University of Arizona
Kevin Hainline
University of Arizona
H. Algera
Academia Sinica
S. Arribas
Centro de Astrobiologia (CAB)
Tom Bakx
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
National Astronomical Observatory of Japan
Nagoya University
Andrew J. Bunker
University of Oxford
S. Carniani
Scuola Normale Superiore di Pisa
Stephane Charlot
Institut d 'Astrophysique de Paris
Jacopo Chevallard
University of Oxford
Mirko Curti
European Southern Observatory (ESO)
Emma Curtis-Lake
University of Hertfordshire
Daniel Eisenstein
Harvard-Smithsonian Center for Astrophysics
K. E. Heintz
University of Geneva
Niels Bohr Institute
Cosmic Dawn Center (DAWN)
Jakob M. Helton
University of Arizona
G. C. Jones
University of Cambridge
R. Maiolino
University of Cambridge
University College London (UCL)
Michael V. Maseda
University of Wisconsin
P.G.P. Pérez-González
Centro de Astrobiologia (CAB)
Clara L. Pollock
Niels Bohr Institute
Cosmic Dawn Center (DAWN)
Brant Robertson
University of California
A. Saxena
University of Oxford
University College London (UCL)
Jan Scholtz
University of Cambridge
Irene Shivaei
Centro de Astrobiologia (CAB)
Fengwu Sun
Harvard-Smithsonian Center for Astrophysics
Sandro Tacchella
University of Cambridge
Hannah Übler
Max Planck Society
D. Watson
Niels Bohr Institute
Cosmic Dawn Center (DAWN)
C. Willott
National Research Council Canada
Zihao Wu
Harvard-Smithsonian Center for Astrophysics
Open Journal of Astrophysics
25656120 (eISSN)
Vol. 9Subject Categories (SSIF 2025)
Astronomy, Astrophysics, and Cosmology
DOI
10.33232/001c.155261