Open AccessNear‐infrared line‐strengths in elliptical galaxies: evidence for initial mass function variations?
Author(s) -
Cenarro A. J.,
Gorgas J.,
Vazdekis A.,
Cardiel N.,
Peletier R. F.
Publication year - 2003
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.2003.06360.x
Subject(s) - physics , astrophysics , velocity dispersion , elliptical galaxy , galaxy , line (geometry) , dwarf spheroidal galaxy , infrared , stars , dwarf galaxy , astronomy , lenticular galaxy , geometry , mathematics
We present new relations between recently defined line‐strength indices in the near‐infrared (CaT*, CaT, PaT, MgI and sTiO) and central velocity dispersion (σ 0 ) for a sample of 35 early‐type galaxies, showing evidence for significant anti‐correlations between Ca ii triplet indices (CaT* and CaT) and log σ 0 . These relations are interpreted in the light of our recent evolutionary synthesis model predictions, suggesting the existence of important Ca underabundances with respect to Fe and/or an increase of the dwarf to giant stars ratio along the mass sequence of elliptical galaxies.