Astrochemistry

On The Origins Of Oxygen: ALMA And JWST Characterise The Multi-phase, Metal-enriched, Star-bursting Medium Within A ‘Normal’ z>11 Galaxy

By Keith Cowing
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astro-ph.GA
August 2, 2025
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On The Origins Of Oxygen: ALMA And JWST Characterise The Multi-phase, Metal-enriched, Star-bursting Medium Within A ‘Normal’ z>11 Galaxy
a, NIRCam false-colour image, where each colour channel was constructed by stacking NIRCam filters as annotated. The placement of the NIRSpec micro-shutters is shown in white (nearly identical across the all visits). Dashed coloured circles indicate the 0.3 “-diameter apertures used to extract the CIRC2 photometry. The [O iii] 88 µm emission and the MIRI/F560W image are overlaid with red and green contours respectively, both drawn at 3σ-4σ-5σ. A red (green) hatched ellipse shows the ALMA restoring beam (F560W point spread function). A horizontal bar indicates a physical scale of 1 kpc at z = 11.122. b, SEDs of the main component (A) of JADES-GS-z11- 0, as observed by NIRCam, MIRI, and NIRSpec/PRISM (Section 2.1), as well as the faint neighbouring source (B) whose photometry (filter curves drawn at the bottom) is consistent with having the same redshift. The best-fit bagpipes models are shown as solid (component A) and dashed (B) coloured lines, with squares indicating the model photometry. c, Best-fit model SFHs of the two components, with shading representing 1σ uncertainty. The dotted black line and grey shading illustrates the rising SFH prior based on dark matter halo accretion (see text for details), scaled to the stellar mass of component A. — astro-ph.GA

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<9.0μJy), implying an obscured star formation rate (SFR) of SFRIR≲6M⊙yr−1 and dust mass of Mdust≲1.0×106M⊙ (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 absorption (DLA) systems to avoid systematic overestimates of up to Δz≈0.5. The [O III] 88 μm luminosity of L[O III]=(1.0±0.3)×108L⊙, 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 (~30% solar), only 400 Myr after the Big Bang.

Joris Witstok, Renske Smit, William M. Baker, Pierluigi Rinaldi, Kevin N. Hainline, Hiddo S. B. Algera, Santiago Arribas, Tom J. L. C. Bakx, Andrew J. Bunker, Stefano Carniani, Stéphane Charlot, Jacopo Chevallard, Mirko Curti, Emma Curtis-Lake, Daniel J. Eisenstein, Kasper E. Heintz, Jakob M. Helton, Gareth C. Jones, Roberto Maiolino, Michael V. Maseda, Pablo G. Pérez-González, Clara L. Pollock, Brant E. Robertson, Aayush Saxena, Jan Scholtz, Irene Shivaei, Fengwu Sun, Sandro Tacchella, Hannah Übler, Darach Watson, Chris J. Willott, Zihao Wu

Comments: 22 pages, 9 figures, 4 tables. Submitted to the Open Journal of Astrophysics
Subjects: Astrophysics of Galaxies (astro-ph.GA)
Cite as: arXiv:2507.22888 [astro-ph.GA] (or arXiv:2507.22888v1 [astro-ph.GA] for this version)
https://doi.org/10.48550/arXiv.2507.22888
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Submission history
From: Joris Witstok
[v1] Wed, 30 Jul 2025 17:59:56 UTC (3,925 KB)
https://arxiv.org/abs/2507.22888
Astrobiology, Astronomy, Astrochemistry,

Keith Cowing

Explorers Club Fellow, ex-NASA Space Station Payload manager/space biologist, Away Teams, Journalist, Lapsed climber, Synaesthete, Na’Vi-Jedi-Freman-Buddhist-mix, ASL, Devon Island and Everest Base Camp veteran, (he/him) 🖖🏻

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