Young stellar objects
Young stellar objects are often shrouded by dust disks ? IR studies are essential.
Several aspects are still matter of debate:
- origin of the IR emission: accretion disks with an inner hole, flaring at large distances from the star
- disk dissipation timescales and particle size distribution
- Planetary systems resulting from coagulation in the disks (Beckwith & Sargent, 1996)
ISO contributes to:
- survey regions at different wavelengths (Omont et al 1999, Cabrit et al 1999) ?complete census of star forming regions
- determine the shape of SED from 2-200 mm ?? constrains the grain properties: ISOPHOT-S spectra are consistent with flaring AD externally illuminated (Robberto et al. 1999)
To be addressed by MID IR high resolution imaging:
- Size of disks for different evolutionary stages, morphology.
- Search for cold companions