Same as in Fig. 2, but the composite spectrum comprises two O6.5 III spectra taken from Hanson et al. (2005). In the left panel, we show the entire wavelength range of the ISAAC spectra, which includes lines of C iv (2.08 μm), He i (2.113, 2.162 μm), the CNO complex (2.115 μm), Brγ (2.166 μm), and He ii (2.189 μm). The best-fit velocities are measured by fitting all features except for the Brγ/He i blend. In the right panel, we show the result of the separate fit to the CNO/He i blend, which was employed to derive velocities.