Normalized [Sii]λ6731 (left panel) and Hαλ6563 (right panel) velocity profiles along the first 6′′ of the blue and the red lobe, obtained from the line PV diagrams in Fig. 1 by spatially integrating the line spectral profiles over the seeing FWHM (~0.8′′, i.e.  ~2 pixels). The label at each profile indicates the distance from the star. The vertical dotted line indicates the zero radial velocity with respect to the star. The dotted and dashed thick lines indicate the velocity peak of the high and the low (and moderate) velocity components, respectively. Note that beyond  ~5′′, only the high-velocity component survives in both lobes.