SIMBAD references

We have investigated the abundance of calcium in early-type galaxies by measuring the strength of the Ca I λ4227 absorption line in their integrated spectra. The database used is the large sample of early-type galaxy integrated spectra in Caldwell and coworkers. We have measured Ca abundances from the Ca I λ4227 feature both by using the Lick Ca4227 index and by defining a new index, Ca4227_r, that avoids the CN4216 molecular band in the continuum on the blueward side of the line. With the new index definition we measure Ca abundances that are systematically ∼0.3 dex higher than with the Lick Ca4227 index. The result is that with the new index definition we obtain higher [Ca/Fe] abundances in early-type galaxies, which are more consistent with their well-known [Mg/Fe] overabundances. Hence, we suggest that Ca might be slightly enhanced, relative to Fe, in early-type galaxies.