Citation for published item:he ossiD w r¡ % imili nd fowerD i h rd qF nd pontD endree F nd h yeD toop nd heunsD om @PHIUA 9q l xy met lli ity s ling rel tions in the ieqvi simul tionsF9D wonthly noti es of the oy l estronomi l o ietyFD RUP @QAF ppF QQSREQQUUF Further information on publisher's website: Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-pro t purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. ABSTRACTWe 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 suite of cosmological hydrodynamical simulations. The slope of the correlation between stellar mass and metallicity of star-forming (SF) gas (M * -Z 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 ≈0.5 dex at ∼10 9 M since z = 3. The simulated relation between stellar mass, metallicity and star formation rate at z 5 agrees remarkably well with the observed fundamental metallicity relation. At M * 10 10.3 M and fixed stellar mass, higher metallicities are associated with lower specific star formation rates, lower gas fractions and older stellar populations. On the other hand, at higher M * , there is a hint of an inversion of the dependence of metallicity on these parameters. The fundamental parameter that best correlates with the metal content, in the simulations, is the gas fraction. The simulated gas fraction-metallicity relation exhibits small scatter and does not evolve significantly since z = 3. In order to better understand the origin of these correlations, we analyse a set of lower resolution simulations in which feedback parameters are varied. We find that the slope of the simulated M * -Z SF,gas relation is mostly determined by stellar feedback at low stellar masses (M * 10 10 M ), and at high masses (M * 10 10 M ) by the feedback from active galactic nuclei.

We analyse the evolutionary history of galaxies formed in a hierarchical scenario consistent with the concordance Lambda cold dark matter (ΛCDM) model focusing on the study of the relation between their chemical and dynamical properties. Our simulations consistently describe the formation of the structure and its chemical enrichment within a cosmological context. Our results indicate that the luminosity–metallicity and the stellar mass–metallicity (LZR and MZR) relations are naturally generated in a hierarchical scenario. Both relations are found to evolve with redshift. In the case of the MZR, the estimated evolution is weaker than that deduced from observational works by approximately 0.10 dex. We also determine a characteristic stellar mass, Mc≈ 3 × 1010 M⊙, which segregates the simulated galaxy population into two distinctive groups and which remains unchanged since z∼ 3, with a very weak evolution of its metallicity content. The value and role played by Mc is consistent with the characteristic mass estimated from the SDSS galaxy survey by Kauffmann et al. Our findings suggest that systems with stellar masses smaller than Mc are responsible for the evolution of this relation at least from z≈ 3. Larger systems are stellar dominated and have formed more than 50 per cent of their stars at z≥ 2, showing very weak evolution since this epoch. We also found bimodal metallicity and age distributions from z∼ 3, which reflects the existence of two different galaxy populations. Although SN feedback may affect the properties of galaxies and help to shape the MZR, it is unlikely that it will significantly modify Mc since, from z= 3 this stellar mass is found in systems with circular velocities larger than 100 km s−1.