Radiative transfer modeling of three T Tauri stars: selecting candidates for studying circumstellar disk evolution

We present modeling work on three young stellar objects that are promising targets for future high-resolution observations to investigate circumstellar disk evolution. The currently available data comprise the spectral energy distribution from optical to millimeter wavelengths which allow constraining the structure of the circumstellar disk using self-consistent radiative transfer models. The results suggest that the assumption of well-mixed dust and gas leads to overestimation of flux in the far-infrared. Observational and theoretical arguments suggest that an overall decrease in far-infrared excess can be explained by dust settling towards the midplane. A new disk model is hence employed to take the effect of dust sedimentation into account. The extended model satisfactorily reproduces all existing observations. The three targets studied here therefore deserve follow-up observations to reveal the evolutionary state of their protoplanetary disks.