Tangential velocities in the v_α/v_δ plane, showing the theoretical locations of sources with circular Galactic orbits and LSR velocities. Six different cases are shown, while each line represents sources at all l positions. The six cases are for two different distances (100 pc, dashed lines; 200 pc, dash-dotted lines), and for three different b positions (b = −20°, green; b = 0°, blue; b = 25°, magenta). The indicated longitude positions at l = 0° (box symbols) and l = 290° (diamond symbols) roughly mark the eastern and western borders of Sco-Cen. The SigMA-selected Sco-Cen members are shown as gray dots (without stability cut). See also Fig. 13 for a separation of the clusters and for the v_α, LSR/v_δ, LSR plane.