The Astrophysical Journal Letters (Jan 2025)
Potential-driven Metal Cycling: JADES Census of Gas-phase Metallicity for Galaxies at 1 < z < 7
Abstract
The gravitational potential is established as a critical determinant of gas-phase metallicity (12+log(O/H)) in low-redshift galaxies, whereas its influence remains unconfirmed at high redshifts. We investigate the correlation between gas-phase metallicity and effective radius ( R _e ) for a sample of galaxies with redshifts ranging from 1 to 7, drawn from JWST Advanced Deep Extragalactic Survey Data Release 3. We calculate the metallicities using four strong-line methods: N2S2H α , R23, N2, and O3N2. After taking out the evolution of size, we find that the offsets of the mass–size relation ( ${\rm{\Delta }}\mathrm{log}{R}_{{\rm{e}}}$ ) are significantly negatively correlated with the offset of the mass–metallicity relation ( ${\rm{\Delta }}\mathrm{log}({\rm{O}}/{\rm{H}})$ ) for the four metallicity tracers. Regardless of the metallicity tracer used, we obtain Spearman rank p- values much less than 0.01, rejecting the null hypothesis that the observed correlation is statistically nonsignificant and attributable to random chance. This is also true for galaxies with z > 3, with p- values less than 0.05 for the four metallicity tracers. We for the first time find evidence of size playing a key role in determining gas-phase metallicity toward cosmic dawn, suggesting that the gravitational potential influences galaxies' material-exchange processes with the surrounding environment in the very early Universe.
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