Same as Fig. C.4 for L1521F. Open symbols are used when the visibility real part has a negative value (since absolute values are shown in the log–log plot). The red Plummer + Gaussian (PG) model that includes an unresolved 0.13′′ FWHM Gaussian component (see Table 6) is statistically better than the black Plummer-only (Pl) model at 231 GHz. The 94 GHz profile can be well modeled with a Plummer-only model.