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

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

Veröffentlichungen: Beitrag in FachzeitschriftArtikelPeer Reviewed


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.
FachzeitschriftThe Astrophysical journal Letters
PublikationsstatusVeröffentlicht - 1 Juni 2015
Extern publiziertJa

ÖFOS 2012

  • 103003 Astronomie
  • 103004 Astrophysik