IMF&ndashMetallicity: A Tight Local Relation Revealed by the CALIFA Survey

Martín-Navarro, I.; Vazdekis, A.; La Barbera, Francesco; Falcón-Barroso, J.; Lyubenova, Mariya; van de Ven, Glenn; Ferreras, Ignacio; Sánchez, S. F.; Trager, S. C.; García-Benito, R.; Mast, D.; Mendoza, M. A.; Sánchez-Blázquez, P.; González Delgado, R.; Walcher, C. J.; The CALIFA Team
Bibliographical reference

The Astrophysical Journal Letters, Volume 806, Issue 2, article id. L31, 5 pp. (2015).

Advertised on:
6
2015
Number of authors
16
IAC number of authors
3
Citations
114
Refereed citations
107
Description
Variations in the stellar initial mass function (IMF) have been invoked to explain the spectroscopic and dynamical properties of early-type galaxies (ETGs). However, no observations have yet been able to disentangle the physical driver. We analyze here a sample of 24 ETGs 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 toward 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 ETGs—metallicity is the main driver of IMF variations, a significant revision of the interpretation of galaxy evolution observables is necessary.
Related projects
Group members
Traces of Galaxy Formation: Stellar populations, Dynamics and Morphology
We are a large, diverse, and very active research group aiming to provide a comprehensive picture for the formation of galaxies in the Universe. Rooted in detailed stellar population analysis, we are constantly exploring and developing new tools and ideas to understand how galaxies came to be what we now observe.
Ignacio
Martín Navarro