Intensity (upper panel) of the [O iii] λ5007 Å, and the electron temperature using [O iii] (λ4958 Å+λ5007 Å)/λ4363 Å ratios along the slit (lower panel). The logarithmic scale is used to show the shell and the even farther extended halo. The flux scale is the same as in Fig. 7. The plus signs indicate the solution by exponential formula of Osterbrock & Ferland (2006). The bars give the solution using the new calibration of Proxauf et al. (2014).