Left: CO(3−2) spectra extracted from four regions (shown in right panel) placed at different positions with respect to the location of the QSO. The spectra have been rebinned to a channel size of 120 km s^-1. The CO line emission is faint or absent in the lower-right spectrum which was extracted from a region south-west of the QSO. Right: CO(3−2) map and contours at the same level of Fig. 1c. The black dotted squares correspond to the regions from where we extracted the four spectra shown in the left panel. The beam of the CO(3−2) map is shown in the bottom-right corner.