NED Abstract 
Copyright by European Southern Observatory (ESO).
Reproduced by permission

2009A&A...495...53L

Physical properties of galaxies and their evolution in the VIMOS VLT Deep
Survey. I. The evolution of the mass-metallicity relation up to z ~ 0.9

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

Abstract. Aims. We want to derive the mass-metallicity relation of
star-forming galaxies up to z ~ 0.9, using data from the VIMOS VLT Deep
Survey. The mass-metallicity relation is commonly understood as the
relation between the stellar mass and the gas-phase oxygen abundance.
Methods: Automatic measurement of emission-line fluxes and equivalent
widths have been performed on the full spectroscopic sample of the VIMOS
VLT Deep Survey. This sample is divided into two sub-samples depending on
the apparent magnitude selection: wide (I_AB_ < 22.5) and deep (I_AB_ <
24). These two samples span two different ranges of stellar masses.
Emission-line galaxies have been separated into star-forming galaxies and
active galactic nuclei using emission line ratios. For the star-forming
galaxies the emission line ratios have also been used to estimate gas-phase
oxygen abundance, using empirical calibrations renormalized in order to
give consistent results at low and high redshifts. The stellar masses have
been estimated by fitting the whole spectral energy distributions with a
set of stellar population synthesis models. Results: We assume at first
order that the shape of the mass-metallicity relation remains constant with
redshift. Then we find a stronger metallicity evolution in the wide sample
as compared to the deep sample. We thus conclude that the mass-metallicity
relation is flatter at higher redshift. At z ~ 0.77, galaxies at 10^9.4^
solar masses have -0.18 dex lower metallicities than galaxies of similar
masses in the local universe, while galaxies at 10^10.2^ solar masses have
-0.28 dex lower metallicities. By comparing the mass-metallicity and
luminosity-metallicity relations, we also find an evolution in
mass-to-light ratio: galaxies at higher redshifts being more active. The
observed flattening of the mass-metallicity relation at high redshift is
analyzed as evidence in favor of the open-closed model.

Key words: galaxies: evolution, galaxies: fundamental parameters, Galaxies:
abundances, galaxies: starburst