First order velocity structure function (VSF) computed from EW (left) and MW projected maps (right). They are displayed in red for the v_x projection, blue for the v_y projection, green for the v_z projection and pink for the v_cen projection. The dispersions are displayed in shaded areas in the same colours. They are presented in the [100, 4000] kpc range, considered as the range of validity of the study (see left panel of Fig. B.1). The range is separated into two fitting ranges: [100, 600] kpc and [600, 1000] kpc, separated by a dashed vertical dotted black line on the plot. The best-fit slope values in each interval are reported in Table 1.