We present preliminary results of an ESO-VLT large programme (AMAZE) aimed at determining the evolution of the mass-metallicity relation at z~3 by means of deep near-IR spectroscopy. Gas metallicities and stellar masses are measured for an initial sample of nine star forming galaxies at z~3.3. When compared with previous surveys, the mass-metallicity relation inferred at z~3.3 shows an evolution significantly stronger than observed at lower redshifts. There are also some indications that the metallicity evolution of low mass galaxies is stronger relative to high mass systems, an effect which can be considered as the chemical version of the galaxy downsizing. The mass-metallicity relation observed at z~3.3 is difficult to reconcile with the predictions of some hierarchical evolutionary models. We shortly discuss the possible implications of such discrepancies.
@article{arxiv.0712.2880,
title = {The evolution of the mass-metallicity relation at z~3},
author = {R. Maiolino and T. Nagao and A. Grazian and F. Cocchia and A. Marconi and F. Mannucci and A. Cimatti and A. Pipino and S. Ballero and A. Fontana and G. L. Granato and F. Matteucci and G. Pastorini and L. Pentericci and G. Risaliti and M. Salvati and L. Silva},
journal= {arXiv preprint arXiv:0712.2880},
year = {2010}
}
Comments
6 pages, 4 figures, to appear in the proceedings of "A Century of Cosmology: Past, Present and Future" (Venezia, August 2007)