Column density radial profiles of C¹⁸O and C¹⁷O compared with beam-convolved line intensity (J = 3−2) radial profiles. Different line styles represent models with various disk masses; column densities in black, C¹⁸O and C¹⁷O line intensities in red and in blue, convolved with a 0.1′′ beam. Models with a central T Tauri star are presented in the left panels, those with a Herbig star in the right panels. Only models with f_large = 0.99 are shown.