Top: position–velocity diagram along the major axis of PA = 199° (east is at left). The central outflow is clearly visible superposed on the smooth rotational velocity gradient (underlined by the yellow line, corresponding to the rotation curve of Fig. 6). Bottom: position–velocity diagram, along the minor axis, of PA = 109° (east is at left). The two components (red and blue) of the outflow are visible, along a slice, where the velocity should be equal to the systemic one (yellow line).