Maps of the modelled luminosity-weighted stellar population properties: ages (top left), total metallicity (top right), alpha-element abundance (bottom left), and iron abundance (bottom right). Black lines display the V-band surface brightness contours from Arnaboldi et al. (2012) in the range from 20 to 23.5 in steps of 0.5 mag arcsec^-2. Colours indicate the SSP equivalent parameters according to the colour bars in the bottom left section of each panel. The inner galaxy (R< ~ 10 kpc) is characterized by homogenous old age, high metallicity, and super solar [α/Fe]; the outer halo shows a more complex behaviour; see extended discussion in Sect. 6.