JADES NIRSpec initial data release for the Hubble Ultra Deep Field: Redshifts and line fluxes of distant galaxies from the deepest JWST Cycle 1 NIRSpec multi-object spectroscopy

We describe the NIRSpec component of the JWST Deep Extragalactic Survey (JADES), and provide deep spectroscopy of $253$ sources targeted with the NIRSpec micro-shutter assembly in the Hubble Ultra Deep Field and surrounding GOODS-South. The multi-object spectra presented here are the deepest so far obtained with JWST, amounting to up to $28\ \mathrm{hours}$ in the low-dispersion ($R \sim 30-300$ ) prism, and up to $7\ \mathrm{hours}$ in each of the three medium-resolution $R \approx 1000$ gratings and one high-dispersion grating, G395H ($R \approx 2700$ ). Our low-dispersion and medium-dispersion spectra cover the wavelength range $0.6-5.3\ \mu\mathrm{m}$ . We describe the selection of the spectroscopic targets, the strategy for the allocation of targets to micro-shutters, and the design of the observations. We present the public release of the reduced 2D and 1D spectra, and a description of the reduction and calibration process. We measure spectroscopic redshifts for $178$ of the objects targeted extending up to $z = 13.2$ . We present a catalogue of all emission lines detected at $\mathrm{S/N} > 5$ , and our redshift determinations for the targets. Combined with the first JADES NIRCam data release, these public JADES spectroscopic and imaging datasets provide a new foundation for discoveries of the infrared universe by the worldwide scientific community.

Astronomy & Astrophysics, Volume 690, id.A288, 32 pages