Top: Bar plot of PAH EWs for the full Ch 1A mosaic (red), nucleus (magenta), circumnuclear region (violet), PAH ring (yellow), and PAH-deficient region (green). Middle: EWs of the PAH 7.7 μm (top) and 11.3 μm (bottom) complexes versus [Ne III]/[Ne II], tracing the radiation-field hardness. Points correspond to the five regions defined above, colour-coded as in the top panel. For comparison, we include Seyfert 1.8-2 nuclei from Gallimore et al. (2010) and Sales et al. (2010). Bottom: EWs of the PAH 7.7 μm (blue) and 11.3 μm (orange) complexes versus H₂ 0−0 S(1) intensity relative to the PAH bands, tracing the role of shock-driven collisional excitation. Symbols denote region type: circle (Ch 1A mosaic), diamond (nucleus), hexagon (circumnuclear), cross (PAH ring), and star (PAH-deficient). EW uncertainties are smaller than or comparable to the symbol size.