2025ApJ...988...19S

We report the first successful Atacama Large Millimeter/submillimeter Array (ALMA) follow-up observations of a secure z > 10 JWST-selected galaxy, by robustly detecting (6.6σ) the [O III]_88 μm_ line in JADES-GS-z14-0 (hereafter GS-z14). The ALMA detection yields a spectroscopic redshift of z = 14.1793 ± 0.0007, and increases the precision on the prior redshift measurement of $z=14.3{2}_{-0.20}^{+0.08}$ from NIRSpec by ≳180×. Moreover, the redshift is consistent with that previously determined from a tentative detection (3.6σ) of C III]_1907,1909 (z = 14.178 ± 0.013), solidifying the redshift determination via multiple line detections. We measure a line luminosity of L_[O iii]88_ = (2.1 ± 0.5) × 10⁸L_⊙, placing GS-z14 at the lower end, but within the scatter of, the local L_[O iii]88_-star formation rate relation. No dust continuum from GS-z14 is detected, suggesting an upper limit on the dust-to-stellar mass ratio of <2 × 10^–3, consistent with dust production from supernovae with a yield y_d < 0.3 M_⊙. Combining a previous JWST/MIRI photometric measurement of the [O III]λλ4959,5007 Å and Hβ lines with CLOUDY models, we find GS-z14 to be surprisingly metal-enriched (Z ∼ 0.05-0.2 Z_⊙) a mere 300 Myr after the Big Bang. The detection of a bright oxygen line in GS-z14 thus reinforces the notion that galaxies in the early Universe undergo rapid evolution.