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

¹ Laboratoire d'Astrophysique de Toulouse-Tarbes, Université de Toulouse, CNRS, Observatoire Midi-Pyrénées, 14 Av. E. Belin, 31400, Toulouse, France e-mail: enrique.perez@ast.obs-mip.fr
² Centro de Astrofísica da Universidade do Porto, Rua das Estrelas, 4150-762, Porto, Portugal
³ Laboratoire d'Astrophysique de Marseille, UMR 6110 CNRS-Université de Provence, 38 rue Frederic Joliot-Curie, 13388 Marseille Cedex 13, France
⁴ Max Planck Institut für Astrophysik, 85741, Garching, Germany
⁵ Institut d'Astrophysique de Paris, UMR 7095, 98 bis Bvd Arago, 75014, Paris, France
⁶ INAF-Osservatorio Astronomico di Bologna, via Ranzani 1, 40127, Bologna, Italy
⁷ IASF-INAF, via Bassini 15, 20133, Milano, Italy
⁸ IRA-INAF, via Gobetti 101, 40129, Bologna, Italy
⁹ INAF-Osservatorio Astronomico di Roma, via di Frascati 33, 00040, Monte Porzio Catone, Italy
¹⁰ Canada France Hawaii Telescope corporation, Mamalahoa Hwy, Kamuela, 96743, USA
¹¹ School of Physics & Astronomy, University of Nottingham, University Park, Nottingham, NG72RD, UK
¹² Astrophysical Institute Potsdam, An der Sternwarte 16, 14482, Potsdam, Germany
¹³ INAF-Osservatorio Astronomico di Brera, via Brera 28, 20021, Milan, Italy
¹⁴ Institute for Astronomy, 2680 Woodlawn Dr., University of Hawaii, Honolulu, Hawaii, 96822, USA
¹⁵ Observatoire de Paris, LERMA, 61 Avenue de l'Observatoire, 75014, Paris, France
¹⁶ Università di Bologna, Dipartimento di Astronomia, via Ranzani 1, 40127, Bologna, Italy
¹⁷ Centre de Physique Théorique, UMR 6207 CNRS-Université de Provence, 13288, Marseille, France
¹⁸ Integral Science Data Centre, ch. d'Écogia 16, 1290, Versoix, Switzerland
¹⁹ Geneva Observatory, ch. des Maillettes 51, 1290, Sauverny, Switzerland
²⁰ Astronomical Observatory of the Jagiellonian University, ul Orla 171, PL-30-244, Kraków, Poland
²¹ INAF-Osservatorio Astronomico di Capodimonte, via Moiariello 16, 80131, Napoli, Italy

Received: 10 July 2008
Accepted: 3 October 2008

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.