Left and central panels: [N II]- and [S II]-BPT diagrams for the disc and outflow components, on the left and on the right respectively, of Circinus. Blue denotes SF-dominated regions, green intermediate regions in the [N II]-BPT and LI(N)ER in the [S II]-BPT, and red AGN-like ionised spectra, colours-coded as a function of the x-axis line ratios (darker shades means higher x-axis line ratios). The black dashed curve is the boundary between star-forming galaxies and AGN defined by Kauffmann et al. (2003), while the black solid curve is the theoretical upper limit on SF line ratios found by Kewley et al. (2001). The black dotted line is the Kewley et al. (2006) boundary between Seyferts and LI(N)ERs. Right panels: [N II]- and [S II]-BPT maps of the outflowing gas component, colour-coded according to BPTs. In the background of all the pictures (grey dots in the BPTs and shaded grey in the corresponding maps), we show the disc and outflow component together. For each velocity bin, we select only the spaxels with a S/N >  5 for all the lines involved.