Sky-subtraction results for the three X-shooter arms for the sky spectrum derived from the same 2D spectrum as the object spectrum (Δt = 0). The input object spectrum (black), the skycorr-corrected spectrum (green), and the corresponding X-shooter pipeline product based on sky interpolation in the 2D spectrum (magenta) are shown. For a better comparison, the latter is shifted by 0.4 dex to lower values. The spectra are not flux calibrated. This explains the apparent flux jump between the UVB and VIS arm at about 0.59 μm and the bump at about 2.14 μm (cf. Parsons et al. 2012). The strong uncorrected lines in the near-IR (mainly between 1.0 and 1.35 μm) were mostly caused by instrumental defects.