MASSIV: Mass Assembly Survey with SINFONI in VVDS

VI. Metallicity-related fundamental relations in star-forming galaxies at 1 < z < 2^⋆,⋆⋆

¹ Institut de Recherche en Astrophysique et Planétologie (IRAP), CNRS, 14 avenue Édouard Belin, 31400 Toulouse, France
e-mail: cdivoy@irap.omp.eu
² IRAP, Université de Toulouse, UPS-OMP, 31028 Toulouse, France
³ Instituto de Astrofísica de Andalucía – CSIC Apdo. 3004, 18080 Granada, Spain
⁴ Aix Marseille Université, CNRS, LAM (Laboratoire d’Astrophysique de Marseille) UMR 7326, 13388 Marseille, France
⁵ Centro de Estudios de Física del Cosmos de Aragón, Plaza San Juan 1, planta 2, 44001 Teruel, Spain
⁶ INAF-IASFBO, via P. Gobetti 101, 40129 Bologna, Italy
⁷ IASF-INAF, via Bassini 15, 20133 Milano, Italy
⁸ Gemini Observatory, 670 N. A’ohoku Place, Hilo, Hawaii 96720, USA

Received: 31 March 2014
Accepted: 18 June 2014

Abstract

Aims. The MASSIV (Mass Assembly Survey with SINFONI in VVDS) project aims at finding constraints on the different processes involved in galaxy evolution. This study proposes to improve understanding of the galaxy mass assembly through chemical evolution using metallicity as a tracer of the star formation and interaction history.

Methods. We analysed the full sample of MASSIV galaxies for which a metallicity estimate has been possible, the 48 star-forming galaxies at z ~ 0.9−1.8, and computed the integrated values of some of the fundamental parameters, such as stellar mass, metallicity, and star formation rate (SFR). The sample of star-forming galaxies at similar redshifts from zCOSMOS was also combined with the MASSIV sample. We studied the cosmic evolution of the mass-metallicty relation, together with the effect of close environment and galaxy kinematics on this relation. We then focussed on the so-called fundamental metallicity relation and other relations between stellar mass, SFR, and metallicity. We investigated whether these relations are really fundamental, i.e. if they do not evolve with redshift.

Results. The MASSIV galaxies follow the expected mass-metallicity relation for their median redshift. We find, however, a significant difference between isolated and interacting galaxies as found for local galaxies: interacting galaxies tend to have a lower metallicity. The study of the relation between stellar mass, SFR, and metallicity gives such large scattering for our sample, even combined with zCOSMOS, that it is difficult to confirm any fundamental relation.