Intensity ratio maps of the south PDR of NGC 7023. The colors from the colorbar correspond to the ratio of the 11.2/3.3 μm ratio on the left and the 8.0/11.2 μm ratio on the right. In the top panels the contour lines follow the H₂ emission (2.12 μm) from 90 to 150 in 6 steps (Arb. Units) (An & Sellgren 2003). In the middle panels the contour lines are based on the ERE (Berné et al. 2008). The lines have been normalized and range from 0.1 to 1 (Arb. Units) with 6 steps. Pixels with a S/N smaller than 3 in the ratio have been discarded. Bottom panel: the IRAC 8.0 μm image with the contours of the 11.2/3.3 μm ratio.