IMF-Metallicity: A Tight Local Relation Revealed by the CALIFA Survey

Journal
Date Issued
2015
Author(s)
Martín-Navarro, Ignacio
•
Vazdekis, Alexandre
•
•
Falcón-Barroso, Jesús
•
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.
•
CALIFA Team
DOI
Description
We acknowledge support from grants AYA2013-48226-C3-1 P and AYA2010-15081 from the Spanish MINECO. C.J.W. acknowledges support through the Marie Curie Career Integration Grant 303912. P.S.-B. acknowledges support from the Ramón y Cajal program, ATA2010-21322-C03-02 (MINECO). J.F.B. and Gvd.V. acknowledge the DAGAL network from the People Programme (Marie Curie Actions) of the European Unions Seventh Framework Programme FP7/2007–2013 under REA grant agreement number PITN-GA-2011-289313.
Abstract
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.
Volume
806
Issue
2
Start page
L31
Uri
Url
Issn Identifier
2041-8205
Ads BibCode
2015ApJ...806L..31M
Rights
open.access
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