James Webb Space Telescope Feed Post

Harvard ADS: Detection of [OIII]88\mum in JADES-GS-z14-0 at z=14.1793

Paper abstract: We report the first successful ALMA follow-up observations of a secure z > 10 JWST-selected galaxy, by robustly detecting (6.6\sigma) the [OIII]_{88\mu m}\, line in JADES-GS-z14-0 (hereafter GS-z14). The ALMA detection yields a spectroscopic redshift of z=14.1793\pm0.0007, and increases the precision on the prior redshift measurement of z=14.32_{-0.20}^{+0.08} from NIRSpec by \gtrsim180\times. Moreover, the redshift is consistent with that previously determined from a tentative detection (3.6\sigma) of CIII]_{1907,1909} (z=14.178\pm0.013), solidifying the redshift determination via multiple line detections. We measure a line luminosity of L_\mathrm{[OIII]88} = (2.1 \pm 0.5)\times10^8\,L_\odot, placing GS-z14 at the lower end, but within the scatter of, the local L_\mathrm{[OIII]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 \times 10^{-3}, consistent with dust production from supernovae with a yield y_d < 0.3\,M_\odot. Combining a previous JWST/MIRI photometric measurement of the [OIII]\lambda\lambda4959,5007\mathrm{\mathring{A}} and H\beta lines with Cloudy models, we find GS-z14 to be surprisingly metal-enriched (Z~0.05 - 0.2\,Z_\odot) a mere 300\,\mathrm{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.