Normalized ISAAC spectra (blue) sorted by the orbital phase (φ) of D2–EB, including the Brγ (2.166 μm)/He i (2.162 μm) blend and the He ii (2.189 μm) line. The composite spectra (red) of two FASTWIND templates of 38 kK and 37 kK, weighted, summed, and shifted to our derived velocities, are overplotted. The best-fit velocites are obtained from the fit of He ii. For clarity, a smoothing window is applied to the observed spectra and a constant is added to the relative fluxes. Absorption features in the wavelength range 2.170 − 2.185μm are due to poor telluric correction.