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arXiv · 2212.09372

Massive galaxy formation caught in action at z~5 with JWST

Shuowen Jin·Nikolaj B. Sillassen·Georgios E. Magdis·Aswin P. Vijayan·Gabriel B. Brammer·Vasily Kokorev·John R. Weaver·Raphael Gobat·Clara Giménez-Arteaga·Francesco Valentino·Malte Brinch·Carlos Gómez-Guijarro·Marko Shuntov·Sune Toft·Thomas R. Greve·David Blanquez Sese
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Abstract

We report the discovery of a compact group of galaxies, CGG-z5, at z~5.2 in the EGS field covered by the JWST/CEERS survey. CGG-z5 was selected as the highest overdensity of galaxies at z>2 in recent JWST public surveys and it consists of six candidate members lying within a projected area of $1.5"\times3"$ (10$\times$20~kpc$^2$). All group members are HST/F435W and HST/F606W dropouts while securely detected in the JWST/NIRCam bands, yielding a narrow range of robust photometric redshifts $5.0 11$) at z~1. This implies that CGG-z5 could be a "proto-massive galaxy" captured during a short-lived phase of massive galaxy formation.

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Shuowen Jin, Nikolaj B. Sillassen, Georgios E. Magdis, Aswin P. Vijayan, Gabriel B. Brammer, Vasily Kokorev, John R. Weaver, Raphael Gobat, Clara Giménez-Arteaga, Francesco Valentino, Malte Brinch, Carlos Gómez-Guijarro, Marko Shuntov, Sune Toft, Thomas R. Greve, David Blanquez Sese. 2022-12-19. Massive galaxy formation caught in action at z~5 with JWST. https://doi.org/10.1051/0004-6361%2F202245724

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