Average STIS spectrum of the He II region from all observations in the 2000–2001 campaign re-binned into 0.05 Å pixels (black histogram). The solid red line tracing the data show the total emission model. The key in the figure identifies the emission components in our model. The velocity scale along the top axis is for He IIλ1640.45, relative to the host galaxy systemic redshift, z = 0.00973 (Theureau et al. 1998). All narrow absorption features are foreground ISM lines.