Distribution of stellar population parameters of the off-centred envelope (red) and the symmetric halo (grey). The histograms are normalized and the number of spectra (N) used in each case is shown in the legend of each panel. Dashed lines indicate the components of the GMM analysis, while the arrows indicate the position of the peak of each component. The off-centred envelope is responsible for a significant shift of the metallicity where it is located, while ages and alpha-element abundance distributions are similar to those inferred for the symmetric halo.