BPT diagrams. Top row, from left to right: [N II] BPT for the five individual components, [N II] BPT for all the components together, [S II] BPT for the five individual components, [S II] BPT for all the components together. Bottom row: Maps with each pixel colour-coded according to the location on the BPT [N II] diagram shown in the top-left panel. Ellipses (or single dot for a_2, bis) show the locations of the different components, with the same colour code as in Fig. 7.