We present the stellar mass–stellar metallicity relationship ( MZR ) in the Cl0024+1654 galaxy cluster at z \sim 0.4 using full spectrum stellar population synthesis modeling of individual quiescent galaxies .
The lower limit of our stellar mass range is M _ { * } = 10 ^ { 9.7 } M _ { \odot } , the lowest galaxy mass at which individual stellar metallicity has been measured beyond the local universe .
We report a detection of an evolution of the stellar MZR with observed redshift at 0.037 \pm 0.007 dex per Gyr , consistent with the predictions from hydrodynamical simulations .
Additionally , we find that the evolution of the stellar MZR with observed redshift can be explained by an evolution of the stellar MZR with their formation time , i.e. , when the single stellar population ( SSP ) - equivalent ages of galaxies are taken into account .
This behavior is consistent with stars forming out of gas that also has an MZR with a normalization that decreases with redshift .
Lastly , we find that over the observed mass range , the MZR can be described by a linear function with a shallow slope , ( { [ Fe / H ] } \propto { ( 0.16 \pm 0.03 ) } \log M _ { * } ) .
The slope suggests that galaxy feedback , in terms of mass-loading factor , might be mass-independent over the observed mass and redshift range .