Two dimensional maps of the median proper motion in the latitude direction corrected for the peculiar motion of the Sun, μ_b, LSR of the two working samples, namely the OB sample (left) and the RGB sample (right). The black dotted lines show circles at different Galactocentric radii, R = 8, 10, 12, 14 and 16 kpc. The sizes of the bins are 0.32 kpc × 0.64 kpc for the OB sample and 0.16 kpc × 0.32 kpc for the RGB sample. We only plot the bins with at least 15 sources. The grey solid lines show azimuths 135° and 225°, while the black horizontal line shows the centre–anti-centre direction. The position of the Sun is shown with a small black star.