Radial velocities of the [Fe ii] 1.644 μm emission for the redshifted and blueshifted parts of the flow. Points taken at the same projected distance for the different slits are offset from one another slightly to avoid confusion. Scatter of values obtained from each 5-minute exposure produces the 1σ error bars. Both the redshifted and blueshifted parts of the flow slow down as the jet emerges from the source. There are no significant differences in the radial velocities observed in the different slit positions.