PV map (top), line profile (middle), and SA signature (bottom) of the [Fe iii] λ2.14 μm (left) and Brγ λ2.160 μm (right) lines of SwSt 1. The SA signal for the two lines are basically reversed, suggesting that they trace different nebular components. Gray levels in the PV map of the [Fe iii] line are at 15%, 20%, and 30% of the intensity peak: gray levels in the PV map of the Brγ line start at 2% of the intensity peak in steps of 10%. The dashed line at the top and bottom panels mark the centroid of the continuum emission.