Correlations between the different empirical PAH ionisation proxies (I_6.2/I_11.2, left panels; I_7.7/I_11.2, middle panels; I_8.6/I_11.2, right panels) and the PAH ionisation parameter (γ) deduced from pyPAHdb modelling. In the top panels, the pixels are colour-coded based on their vertical distance from the edge of the mosaic, which is indicative of the projected distance from θ¹ Ori C. In the bottom panels, pixels corresponding to each of the five key physical regions are assigned a specific colour (H ii in green, APDR in red, DF1 in blue, DF2 in orange, and DF3 in pink), with the average values from each template indicated with a different symbol. Pixels outside the five zones are shown in grey.