Spectra (in black) of IRS 6W in the ¹²CO P(1), P(2), P(4) and P(5) transitions. Also shown (in red) are the spectra of the standard stars observed close to the science observation to correct for telluric lines. The blanked areas correspond to regions in the spectrum where the telluric corrections were not successful. The red arrows indicate the local absorptions at velocities listed in Table 1. The other colored arrows indicate the absorptions at the same velocities as in Figs. 3 and 4. The scaling and/or shifting factors of the spectra are given in red and black for the standard star and the GC object, respectively.