JADES-GS-z14-0 was recently confirmed by JWST/NIRSpec to be at z = 14.3, making it the most distant galaxy currently known (Carniani et al. 2024). It is exceptionally luminous for its redshift, allowing a photometric MIRI detection (Helton et al. 2024), as well as spatially extended, suggesting a stellar origin of the emission. New follow-up data from a contentious ALMA DDT programme was released on Monday morning which, as shown in two papers appearing on Tuesday’s arXiv, reveal a robust detection of [OIII] 88 μm at z = 14.18 in less than 3 hours of integration – a remarkable improvement compared to the previous ALMA redshift record holder, MACS1149-JD1 at z = 9.1 (Hashimoto et al. 2018). The [OIII] line seen by ALMA consolidates the tentative redshift suggested by a 3σ CIII] line in the NIRSpec/PRISM spectrum, thereby pointing towards substantial DLA absorption or a dominant two-photon continuum, allowing an estimate of the dynamical mass closely matching the stellar mass, and constraining the metallicity to be surprisingly high, perhaps at >20%. Meanwhile, a non-detection of the dust-continuum is consistent with expected stellar yields. Finally breaking a streak of unsuccessful line-scanning attempts in z > 10 galaxy candidates with ALMA, these observations demonstrate the combined constraining power of JWST and ALMA at the redshift frontier.
