Gas (Σ_g, solid lines) and dust (Σ_d, dashed lines) surface densities for the inner 180 au of our fiducial disk models. Top panel: initial SMOOTH model without any gaps or rings. The grey star symbol indicates the gas surface density of 44.4 g cm⁻² as measured by Booth et al. (2019) using ¹³C¹⁷O J = 3−2 observationswith a spatial resolution of ≈70 au. Bottom panel: models using the same fitted dust surface density profile but varying gas surface density profiles (see Sect. 2.4). All models are described in Table 1.