Top panel: I_3.3μm (blue) and I_3.4μm (cyan) band emission according to the distance to the star. Values are the sum of the integrals of the Gaussians related to each feature and averaged for different distances from the star in 0.1′′ step. Normalised 1∕d² functions arealso plotted (dotted black lines) for clarity. Bottom panel: I_3.4μm∕I_3.3μm band ratio (green) according to the distance to the star. The transparent grey box on the left represents the distance up to which the cavity is extended in the POLARIS simulations (~ 0.12′′ or 13 au).