Distribution of the mean observed rotational velocity v_ϕ inside x–y pixels for our final sample of RGB stars (left). The size of the bin is 150 pc in both x and y coordinates, respectively. We added dashed, black circles at 5 kpc, R₀ = 8.277 kpc, 12 and 14 kpc to ease visualisation. Square root of the radial and azimuthal diagonal components of the velocity dispersion tensor in radial bins of 1 kpc (right).