The JWST Advanced Deep Extragalactic Survey: Discovery of an Extreme Galaxy Overdensity at z = 5.4 with JWST/NIRCam in GOODS-S

• DOI: 10.3847/1538-4357/ad0da7
• Publication Date: 2024-02-13T13:06:12Z
• Authors: Jakob M. Helton; Fengwu Sun; Charity Woodrum; Kevin N. Hainline; Christopher N. A....; George H. Rieke; Marcia J. Rieke; Sandro Tacchella; Brant Robertson; Benjamin D. Johnson; Stacey Alberts; Daniel J. Eisenstein; Ryan Hausen; Nina R. Bonaventura; Andrew Bunker; Stephane Charlot; Mirko Curti; Emma Curtis-Lake; Tobias J. Looser; Roberto Maiolino; Chris Willott; Joris Witstok; Kristan Boyett; Zuyi Chen; Eiichi Egami; Ryan Endsley; Raphael E. Hviding; Daniel T. Jaffe; Zhiyuan Ji; Jianwei Lyu; Lester Sandles
• Keywords: Galaxy formation; Early universe; 500; FOS: Physical sciences; 5109 Space Sciences; High-redshift galaxy clusters; Astrophysics; Astrophysics - Astrophysics of Galaxies; QB460-466; 5101 Astronomical Sciences; Galaxy evolution; Astrophysics of Galaxies (astro-ph.GA); High-redshift galaxies; 51 Physical Sciences

Abstract We report the discovery of an extreme galaxy overdensity at z = 5.4 in GOODS-S field using James Webb Space Telescope (JWST)/NIRCam imaging from JADES and JEMS alongside JWST/NIRCam wide-field slitless spectroscopy FRESCO. identified potential members Hubble Telescope+JWST photometry spanning λ 0.4–5.0 μ m. These data provide accurate well-constrained photometric redshifts down to m ≈ 29–30 mag. subsequently confirmed N 81 galaxies 5.2 &lt; 5.5 JWST over 3.9–5.0 through a targeted line search for H α around best-fit redshift. verified that 42 these reside field, while 39 density ∼10 times random volume. Stellar populations were inferred used construct star-forming main sequence, where protocluster appeared more massive exhibited earlier star formation (and thus older stellar populations) when compared their counterparts. estimate total halo mass this large-scale structure be <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mn>12.6</mml:mn> <mml:mo>≲</mml:mo> <mml:msub> <mml:mrow> <mml:mi>log</mml:mi> </mml:mrow> <mml:mn>10</mml:mn> </mml:msub> <mml:mfenced close=")" open="("> <mml:mi>M</mml:mi> <mml:mi>halo</mml:mi> <mml:mo stretchy="true">/</mml:mo> <mml:mo>⊙</mml:mo> </mml:mfenced> <mml:mn>12.8</mml:mn> </mml:math> empirical relation, which is likely underestimate as result incompleteness. Our demonstrates power constraining dark matter assembly very early cosmic times.