IMF - metallicity: a tight local relation revealed by the CALIFA survey
Abstract
Variations in the stellar initial mass function (IMF) have been invoked to explain the spectroscopic and dynamical properties of early-type galaxies. However, no observations have yet been able to disentangle the physical driver. We analyse here a sample of 24 early-type galaxies drawn from the CALIFA survey, deriving in a homogeneous way their stellar population and kinematic properties. We find that the local IMF is tightly related to the local metallicity, becoming more bottom-heavy towards metal-rich populations. Our result, combined with the galaxy mass-metallicity relation, naturally explains previous claims of a galaxy mass-IMF relation, derived from non-IFU spectra. If we assume that - within the star formation environment of early-type galaxies - metallicity is the main driver of IMF variations, a significant revision of the interpretation of galaxy evolution observables is necessary.
Keywords
Cite
@article{arxiv.1506.00638,
title = {IMF - metallicity: a tight local relation revealed by the CALIFA survey},
author = {Ignacio Martín-Navarro and Alexandre Vazdekis and Francesco La Barbera and Jesús Falcón-Barroso and Mariya Lyubenova and Glenn van de Ven and Ignacio Ferreras and S. F. Sánchez and S. C. Trager and R. García-Benito and D. Mast and M. A. Mendoza and P. Sánchez-Blázquez and R. González Delgado and C. J. Walcher and the CALIFA team},
journal= {arXiv preprint arXiv:1506.00638},
year = {2015}
}
Comments
Accepted for publication in ApJL. 6 pages, 4 figures