Upper panel: azimuthally averaged dust and gas surface densities of model fid_dres after 1000 orbits at 48 au. Dust density profiles are normalized to the gas peak value at the location of ring 1. Lower panel: azimuthally averaged optical depths of model mid after 1000 orbits at 48 au compared to the observed optical depth τ_obs. Simulated optical depths are normalized to τ_obs at the location of ring 1.