Comparison of the fraction of the [Cii] emission originating from ionised gas as determined from the observed map of the [Nii] 205 μm line emission at 17″ resolution (left panel), and that as determined from a synthetic map of the [Nii] 205 μm line emission estimated using the 24 μm emission at 12″ resolution (right panel) via the correlation presented in Fig. 8. The maps are centred on , (J2000.0) and the black contours from the F_TIR map (see Fig. 1) represent TIR flux levels as listed in the caption of Fig. 4.