Distribution of stars in the gravitational potential-circularity parameter space for Au6 at z = 0. We have normalised the potential to the maximum of its absolute value to make the values independent of galactic mass and restricted them to the range [−1,0]. The circularity parameter, on the other hand, has been calculated as $ϵ=j_z{j}_{\mathrm{c}\mathrm{i}\mathrm{r}\mathrm{c}}^{-1}$, where j_z is the specific angular momentum in the z-direction of each star and $j_{\mathrm{c}\mathrm{i}\mathrm{r}\mathrm{c}}(R)=R\sqrt{G{M}_R/R}$ the angular momentum of a circular orbit of radius R. In this figure, particles near ε ≈ 1 describe circular orbits, while particles near ε ≈ 0 show random motion. Stars with ẽ ≈ −1 are closer to the centre of the galaxy than particles with ẽ ≈ 0. Dashed lines delimit the different components in each panel, as described in the text. Fig. A.1 shows this figure for each galaxy in the selected sample of galaxies.