Resolved [SII]–BPT (upper panels) and [NII]–BPT (lower panels) diagrams for each spaxel with S/N > 3 in each line. The data points in the BPT diagrams (left panels) are colour coded as a function of their [SII]/Hα and [NII]/Hα ratios for the [SII]–BPT and [NII]–BPT, respectively. The same colours are used in the corresponding maps (right panels), where the contours shown in Fig. 4 are overplotted. The QSO location is marked with a black cross.