Galaxy metallicity scaling relations in the EAGLE simulations

Understand

We quantify the correlations between gas-phase and stellar metallicities and global properties of galaxies, such as stellar mass, halo mass, age and gas fraction, in the Evolution and Assembly of GaLaxies and their Environments (EAGLE) suite of cosmological hydrodynamical simulations.

• The slope of the correlation between stellar mass and metallicity of star-forming (SF) gas ($M_*-Z_{\rm SF,gas}$ relation) depends somewhat on resolution, with the higher-resolution run reproducing a steeper slope.
• This simulation predicts a non-zero metallicity evolution, increasing by $\approx 0.5$ dex at $\sim 10^9 {\rm M}_{\odot}$ since $z = 3$.
• The simulated relation between stellar mass, metallicity and star formation rate at $z \lesssim 5$ agrees remarkably well with the observed fundamental metallicity relation.