Same as Fig. 3 but plotting also the range of EMILES-BaSTI SSP models’ predictions based on results (age, metallicity, IMF, and abundance ratios) from the optical spectral range. Predictions for M31 and M87 are plotted as hatched light-blue and solid gray shaded regions, respectively (see the text for details). Note that, with the exception of the outermost radial bin for M87 (with larger error bars), predictions from the optical are consistent with observed line strengths for NaI2.21 and CaI2.26 (top panels), for both M31 and M87. For the Fe indices, there is some disagreement (at 2–3 sigma level) between data and models, while large deviations are found for Mg and CO indices (see the text).