Chemo-evolutionary Population Synthesis II.

Here we fit in detail ~20 absorption lines and six optical and near-infrared colors, following two approaches: fitting a single-age, single-metallicity model and fitting our full chemical evolutionary model.

We find that all the iron lines are weaker than the best-fitting models predict, indicating that the iron abundance is anomalous and deficient. We also find that the Ca I index at 4227 A is much lower than predicted by the models. We can obtain good fits for all the other lines and observed colors with models of old and metal-rich stellar populations and can show that the observed radial gradients are due to metallicity decreasing outward.