Radial velocity curves of the Hα− (filled circles) and Hα+ (open circles) emission components (symbols are plotted with areas proportional to ﹩W_{\lambda }﹩). The global fit made using the Katz et al. (1982) nodding motions model is shown as a solid line. The × symbols show the jet velocities determined by Marshall et al. (2002) from Chandra HETGS observations of X‐ray lines.