Physical properties of galaxies and their evolution in the VIMOS VLT Deep Survey - II. Extending the mass-metallicity relation to the range z ≈0.89–1.24

E. Pérez-Montero, T. Contini, F. Lamareille, J. Brinchmann, C. J. Walcher, S. Charlot, M. Bolzonella, L. Pozzetti, D. Bottini, B. Garilli, V. Le Brun, O. Le Fèvre, D. Maccagni, R. Scaramella, M. Scodeggio, L. Tresse, G. Vettolani, A. Zanichelli, C. Adami, S. Arnouts, S. Bardelli, A. Cappi, P. Ciliegi, S. Foucaud, P. Franzetti, I. Gavignaud, L. Guzzo, O. Ilbert, A. Iovino, H. J. McCracken, B. Marano, C. Marinoni, A. Mazure, B. Meneux, R. Merighi, S. Paltani, R. Pellò, A. Pollo, M. Radovich, D. Vergani, G. Zamorani, E. Zucca

Abstract
Aims. We present a continuation of our study about the relation between stellar mass and gas-phase metallicity in the VIMOS VLT Deep Survey(VVDS). In this work we extend the determination of metallicities up to redshift ≈1.24 for a sample of 42 star forming galaxies with a mean redshift value of 0.99.
Methods. For a selected sample of emission-line galaxies, we use both diagnostic diagrams and empirical calibrations based on [Oii] emission lines along with the empirical relation between the intensities of the [Oiii] and [Neiii] emission lines and  the theoretical ratios between Balmer recombination emission lines to identify star-forming galaxies and to derive their metallicities. We derive stellar masses by fitting the whole spectral energy distribution with a set of stellar population synthesis models.
Results. These new methods allow us to extend the mass-metallicity relation to higher redshift. We show that the metallicity determinations are consistent with more established strong-line methods. Taken together this allows us to study the evolution of the mass-metallicity relation up to z ≈ 1.24 with good control of systematic uncertainties. We find an evolution with redshift of the average metallicity of galaxies very similar to those reported in the literature: for a given stellar mass, galaxies at z ∼ 1 have, on average, a metallicity ∼0.3 dex lower than galaxies in the local universe. However we do not see any significant metallicity evolution between redshifts z ∼ 0.7 (Paper I) and z ∼ 1.0 (this paper). We find also the same flattening of the mass-metallicity relation for the most massive galaxies as reported in Paper I at lower redshifts, but again no apparent evolution of the slope is seen between z ∼ 0.7 and z ∼ 1.0.

Advances in Space Research
Volume 495, Page 73
February 2009

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