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Abstract Our understanding of the early Universe has long been limited by biased galaxy samples selected through various color criteria. With deep JWST infrared imaging, mass-complete galaxy samples can now be studied up to z ∼ 8 for the first time. However, recent work has revealed systematic uncertainties in measuring the physical properties of galaxies based solely on JWST/NIRCam and Hubble Space Telescope (HST) photometry, due to their limited wavelength coverage. This highlights the need for supplementary data, particularly in the rest-frame UV and near-infrared. Here we present the ULTIMATE-deblending project, which will eventually deliver self-consistent UV to radio photometry for galaxies detected in deep JWST surveys, including both NIRCam and MIRI data. In this first paper, we release a 50-band photometric catalog spanning CFHT U to JWST/MIRI F1800W, covering a total of 627.1 arcmin 2 across two JWST/PRIMER fields. We detail the reduction of the JWST imaging data, the photometric procedures, and the spectral-energy-distribution-fitting methodology used to derive the galaxy properties. Compared with photometry including only HST and JWST bands, the inclusion of deblended low-resolution photometry from ground-based telescopes improves the accuracy of photometric redshifts by ∼40%, while reducing the outlier fraction by ∼60%. This galaxy sample can serve as a key reference for statistical studies of galaxy formation and evolution in the early Universe. All catalogs and JWST mosaics from the ULTIMATE-deblending project have been made publicly available.
Sun et al. (Mon,) studied this question.