Comparison between α_visc measured from R_CO, 90% (solid line) and theinput α_visc (dashed line). The colors correspond to the input α_visc of the model. Top, middle, and bottom panels: models with different stellar masses (cf. Table 1). The red crosses denote where R_CO, 90%∕R_c = 2.3 and R_CO, 90% encloses 90% of M_disk (cf. Sect. 3.4 and Fig. 4). The red crosses denote where R_CO, 90%∕R_c = 2.3, that is, where R_CO, 90% encloses 90% of the total disk mass (see Sect. 3.4).