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arXiv · 2603.05289

ULTIMATE-deblending I. A 50-band Ultraviolet to Mid-infrared Photometric Catalog Combining Space- and Ground-based Data in the JWST/PRIMER survey

Hanwen Sun·Tao Wang·Ke Xu·David Elbaz·Emiliano Merlin·Cheng Cheng·Emanuele Daddi·Shuowen Jin·Wei-hao Wang·Longyue Chen·Adriano Fontana·Zhen-Kai Gao·Jiasheng Huang·Benjamin Magnelli·Valentina Sangalli·Yijun Wang·Tiancheng Yang·Yuheng Zhang·Luwenjia Zhou
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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 $z \sim 8$ for the first time. However, recent work has revealed systematic uncertainties in measuring physical properties of galaxies based solely on JWST/NIRCam and 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 $\sim$40%, while reducing the outlier fraction by $\sim$60%. This galaxy sample can serve as a key reference for statistical studies of galaxy formation and evolution in the early Universe. The UV-to-MIR catalogs and JWST mosaics from the ULTIMATE-deblending project have been made publicly available.

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Hanwen Sun, Tao Wang, Ke Xu, David Elbaz, Emiliano Merlin, Cheng Cheng, Emanuele Daddi, Shuowen Jin, Wei-hao Wang, Longyue Chen, Adriano Fontana, Zhen-Kai Gao, Jiasheng Huang, Benjamin Magnelli, Valentina Sangalli, Yijun Wang, Tiancheng Yang, Yuheng Zhang, Luwenjia Zhou. 2026-06-18. ULTIMATE-deblending I. A 50-band Ultraviolet to Mid-infrared Photometric Catalog Combining Space- and Ground-based Data in the JWST/PRIMER survey. https://doi.org/10.3847/1538-4365%2Fae69d2

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