TY - JOUR

T1 - Early Results from GLASS-JWST. XXI. Rapid Asembly of a Galaxy at z = 6.23 Revealed by Its C/O Abundance

AU - Jones, Tucker

AU - Sanders, Ryan

AU - Chen, Yuguang

AU - Wang, Xin

AU - Morishita, Takahiro

AU - Roberts-Borsani, Guido

AU - Treu, Tommaso

AU - Dressler, Alan

AU - Merlin, Emiliano

AU - Paris, Diego

AU - Santini, Paola

AU - Bergamini, Pietro

AU - Henry, A.

AU - Huntzinger, Erin

AU - Nanayakkara, Themiya

AU - Boyett, Kristan

AU - Bradac, Marusa

AU - Brammer, Gabriel

AU - Calabró, Antonello

AU - Glazebrook, Karl

AU - Grasha, Kathryn

AU - Mascia, Sara

AU - Pentericci, Laura

AU - Trenti, Michele

AU - Vulcani, Benedetta

N1 - Publisher Copyright: © 2023. The Author(s). Published by the American Astronomical Society.

PY - 2023/7/3

Y1 - 2023/7/3

N2 - The abundance of carbon relative to oxygen (C/O) is a promising probe of star formation history in the early universe, as the ratio changes with time due to production of these elements by different nucleosynthesis pathways. We present a measurement of log ( C / O ) = − 1.01 ± 0.12 (stat) ±0.15 (sys) in a z = 6.23 galaxy observed as part of the GLASS-JWST Early Release Science Program. Notably, we achieve good precision thanks to the detection of the rest-frame ultraviolet O iii], C iii], and C iv emission lines delivered by JWST/NIRSpec. The C/O abundance is ∼0.8 dex lower than the solar value and is consistent with the expected yield from core-collapse supernovae, indicating that longer-lived intermediate-mass stars have not fully contributed to carbon enrichment. This in turn implies rapid buildup of a young stellar population with age ≲100 Myr in a galaxy seen ∼900 Myr after the big bang. Our chemical abundance analysis is consistent with spectral energy distribution modeling of JWST/NIRCam photometric data, which indicates a current stellar mass log M * / M ☉ = 8.4 − 0.2 + 0.4 and specific star formation rate ≃20 Gyr−1. These results showcase the value of chemical abundances and C/O in particular to study the earliest stages of galaxy assembly.

AB - The abundance of carbon relative to oxygen (C/O) is a promising probe of star formation history in the early universe, as the ratio changes with time due to production of these elements by different nucleosynthesis pathways. We present a measurement of log ( C / O ) = − 1.01 ± 0.12 (stat) ±0.15 (sys) in a z = 6.23 galaxy observed as part of the GLASS-JWST Early Release Science Program. Notably, we achieve good precision thanks to the detection of the rest-frame ultraviolet O iii], C iii], and C iv emission lines delivered by JWST/NIRSpec. The C/O abundance is ∼0.8 dex lower than the solar value and is consistent with the expected yield from core-collapse supernovae, indicating that longer-lived intermediate-mass stars have not fully contributed to carbon enrichment. This in turn implies rapid buildup of a young stellar population with age ≲100 Myr in a galaxy seen ∼900 Myr after the big bang. Our chemical abundance analysis is consistent with spectral energy distribution modeling of JWST/NIRCam photometric data, which indicates a current stellar mass log M * / M ☉ = 8.4 − 0.2 + 0.4 and specific star formation rate ≃20 Gyr−1. These results showcase the value of chemical abundances and C/O in particular to study the earliest stages of galaxy assembly.

U2 - 10.3847/2041-8213/acd938

DO - 10.3847/2041-8213/acd938

M3 - Letter

AN - SCOPUS:85164432097

VL - 951

JO - The Astrophysical Journal Letters

JF - The Astrophysical Journal Letters

SN - 2041-8205

IS - 1

M1 - L17

ER -