FitCGplus, a model tool for protoplanetary disks

This is an interactive tool for applying the model of Dullemond, Dominik & Natta (2001) to SEDs of T Tauri stars, Herbig Ae/Be stars and Brown Dwarfs.

There is an IDL version and a newer FORTRAN version. The IDL version is public domain. Those interested in the FORTRAN version (which has many more capabilities) can contact me at dullemon@mpia.de.

Download FITCGPLUS 2.1

REMARK 1: In Version 2.0 of the code, if one put incl=0.0, the flux of the inner rim was calculated averaged over inclination (special option). This was confusing to most users. In version 2.1 (the one downloadable above) this option is removed. Incl=0.0 now really means incl=0.0. Note, however, that the rim in this simple model is assumed to be vertical. For incl=0.0 the rim will therefore have no projected surface to the user and the rim flux=0.0. More realistic models, such as the rounded off rim of Isella & Natta (2005), should at some point be built in. If there are volunteers, let me know. For the moment I do not have the time to do this.

REMARK 2: On the "Disks to Planets" conference in Pasadena one speaker claimed that there is a factor 1/2 missing in the equation 14 of Dullemond, Dominik & Natta (2001). This claim is not correct. Such a factor of 1/2 is only there in the case of optically thin models with grey grains. However, our model is optically thick. With our simple assumption that the rim is a solid blackbody radiating surface, our equation is correct. Having said that, it should be clear that in reality the inner rim can have a much more complex structure than assumed in our paper. That might certainly change the inner radius. But, due to flux conservation the rim flux will be still high. Some of this flux might however radiate at somewhat longer wavelength. How much this reduced the near-IR flux is still an issue of debate. A detailed 2-D/3-D radiative transfer study of the rim is required to resolve this issue. We do acknowledge that in 2-D/3-D models the inner rim flux tends to be on average lower than what is seen in many Herbig stars.

REMARK 3: Please be very careful not to over-interpret the results of this code. The model is highly simplified. By now multi-dimensional radiative transfer techniques are becoming so mainstream that it may even be advisable to drop the Chiang & Goldreich approach (used in this code) altogether and use these multi-dimensional techniques. I have now released the public version of my own multi-dimensional radiative transfer code RADMC.