DUALZ—Deep UNCOVER-ALMA Legacy High-Z Survey

We present the survey design and initial results of the Atacama Large Millimeter/submillimeter Array (ALMA) Cycle 9 program of DUALZ, which aims to establish a joint ALMA and JWST public legacy field targeting the massive galaxy cluster A2744. DUALZ features a contiguous 4 ′ × 6 ′ ALMA 30 GHz-wide mosaic in Band 6, covering areas of μ > 2 down to a sensitivity of σ = 32.7 μJy. Through a blind search, we identified 69 dust continuum sources at a signal-to-noise ratio (SNR) ≳ 5.0 with median redshift and intrinsic 1.2 mm flux of z = 2.30 and S 1.2mm int = 0.24 mJy. Of these, 27 have been spectroscopically confirmed, leveraged by the latest NIRSpec observations, while photometric redshifts are also constrained by the comprehensive Hubble Space Telescope (HST), NIRCam, and ALMA data sets for the remaining sources. With priors, we further identify a [C ii]158 μm line emitter at z = 6.3254 ± 0.0004, confirmed by the latest NIRSpec spectroscopy. The NIRCam counterparts of the 1.2 mm continuum exhibit undisturbed morphologies, denoted either by disk or spheroid, implying the triggers for the faint millimeter emission are less catastrophic than mergers. We have identified eight HST-dark galaxies (F150W > 27 mag, F150W − F444W > 2.3) and two JWST-dark (F444W > 30 mag) galaxy candidates among the ALMA continuum sources. The former includes face-on disk galaxies, hinting that substantial dust obscuration does not always result from inclination. We also detect a marginal dust emission from an X-ray-detected galaxy at z_spec = 10.07, suggesting an active coevolution of the central black hole and its host. We assess the infrared luminosity function up to z ∼ 10 and find it is consistent with predictions from galaxy formation models. To foster diverse scientific outcomes from the community, we publicly release reduced ALMA mosaic maps, cubes, and the source catalog at https://jwst-uncover.github.io/DR2.html#DUALZ.