SIMBAD references

We present new relations between recently defined line-strength indices in the near-infrared (CaT*, CaT, PaT, MgI and sTiO) and central velocity dispersion (σ₀) for a sample of 35 early-type galaxies, showing evidence for significant anti-correlations between Caii triplet indices (CaT* and CaT) and log σ₀. 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.