Christian MAIER
(University of Vienna, Institute of Astrophysics)
The widely used reference mass-metallicity relation (MZR) at z>2 from the Erb et al. (2006) study has been affected by the sample selection and unknown AGN contribution, and was based on limited spectroscopic information (1-2 emission lines), yielding large uncertainties in metallicities.To better constrain the MZR of galaxies at z>2, we used VLT and SUBARU near-infrared spectroscopy to measure, for 2<z<2.5 zCOSMOS main sequence (MS) galaxies, the strengths of (up to) five emission lines: [OII]3727, Hbeta, [OIII]5007, Halpha and [NII]6584. These emission lines were used to measure reliable gas metallicities [O/H] and SFRs, and to explore the (Type-2) AGN contribution from the BPT diagram. We found a larger evolution of the MZR of z>2 MS galaxies compared to the Erb et al. study, and also an evolution of the fundamental metallicity relation (FMR) compared to z<1, where the FMR is consistent with the local relation. New insights into the (chemical) galaxy evolution are gained from a comparison of these observations with the gas-regulation model of Lilly et al. (2013), which predicts the MZR and FMR evolution in the context of dark matter haloes of galaxies.