Left: the [Ne II] line averaged over the W source, the symmetrized profile made by reflecting the red half of the line, the best single Gaussian fit to the symmetrized data, and the residuals of the original, non-symmetrized data. X-axis units are km s⁻¹ and Y axis units are erg(s cm⁻¹ cm² sr)⁻¹. Note that the original data and the symmetrized are very similar except in the high noise region around 830 km s⁻¹. Right: the same as the left panel, with another Gaussian appropriate for the “blue bump” added. The formal significance of the second Gaussian is low because of the high noise.