ELPIS: Accelerated Metal and Dust Enrichment in a Protocluster Core at z ≈ 8
Journal article, 2025
We present a study of the metal, dust, and molecular gas content in galaxies within the A2744-z7p9OD protocluster at z approximate to 7.88. We focus on two galaxy groups-the Quintet and the Chain-which are covered by the Emission-Line Protocluster Imaging Survey (ELPIS) of the furthest overdensity beyond Pandora's Cluster A2744. [C ii] 158 mu m emission is detected in five galaxies, revealing molecular gas reservoirs with log(Mgas/M circle dot)similar to 9.0 -9.6, while dust continuum at the observed frame of 1.26 mm is detected in three galaxies, yielding dust masses of log(Mdust/M circle dot)similar to 6.0 -6.4, assuming a dust temperature of Tdust=45-15+15 K. The derived properties-including stellar-to-dust mass ratios of log(Mdust/M star)similar to-3 to -2 at log(M star/M circle dot)approximate to 9 and dust-to-gas mass ratios of log(Mdust/Mgas)similar to-4 to -3 at 12+log(O/H)approximate to 8 -place these galaxies in an intermediate regime: higher than the very low ratios expected from supernova-driven dust production but still below the levels attained once efficient grain growth dominates. These values indicate a transition phase of dust mass assembly, likely reflecting the onset of grain growth via metal accretion under accelerated evolution in the protocluster core.
Author
Hideki Umehata
Nagoya University
Yoichi Tamura
Nagoya University
Yoshinobu Fudamoto
Chiba University
Yurina Nakazato
Flatiron Institute
University of Tokyo
Daniel Ceverino
Universidad Autonoma de Madrid (UAM)
Naoki Yoshida
University of Tokyo
Akio K. Inoue
Waseda University
Ryota Ikeda
The Graduate University for Advanced Studies (SOKENDAI)
National Astronomical Observatory of Japan
Yuma Sugahara
Waseda University
Shutaro Inui
Nagoya University
Santiago Arribas
Spanish National Research Council (CSIC)
Tom Bakx
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
Masato Hagimoto
Nagoya University
Takuya Hashimoto
University of Tsukuba
Luis Colina
Spanish National Research Council (CSIC)
Yi W. Ren
Waseda University
Wataru Osone
University of Tsukuba
Alejandro Crespo Gomez
Space Telescope Sci Inst STScI, 3700 San Martin Dr
Ken Mawatari
Waseda University
Javier Alvarez-Marquez
Spanish National Research Council (CSIC)
Astrophysical Journal Letters
2041-8205 (ISSN) 2041-8213 (eISSN)
Vol. 993 2 L50Subject Categories (SSIF 2025)
Astronomy, Astrophysics, and Cosmology
DOI
10.3847/2041-8213/ae1603