PAHs emission (i.e., continuum-subtracted) models for IRS 48 (top) and HD 179218 (bottom) adapted from Maaskant et al. (2014) and Seok & Li (2017), respectively. The spectra are normalized to the peak emission at 6.3 μm. Top: the small-dotted line corresponds to the total PAH emission, the dashed line to the emission from ionized PAHs in optically thin environments like the gap, and the large-dotted line corresponds to the emission from neutral PAHs in the optically thick disk. Bottom: the model for the total PAH emission in HD 179218 shows a prominent feature at 8.6 μm and a weakerfeature at 11.3 μm.