Dr. Inga Kamp
STSCI

University of Florida Astronomy Colloquium - Feb 10th, 2006

The evolution of protoplanetary disks: boundary conditions for planet formation

The diversity of the discovered extrasolar planets and planetary systems challenges the current planet formation models and has also revived research in protoplanetary disks, the birthplaces of planetary systems. The physical and chemical conditions in protoplanetary disks set strong boundary conditions on the process of planet formation.

Although the dust component of these disks has been studied in considerable detail (grain composition, size distribution and mineralogy), very little is known about the gas, which comprises in fact 99% of the disk mass. Recent publications have shown that dust grain growth affects these disks already in very early stages; thus deriving disk characteristics such as the disk mass from thermal emission of small grains is rather uncertain. A more direct approach is the evaluation of gas tracers probing various aspects of physical disk models such as mass, disk flaring, disk extension, shadowing, evaporation etc.. Such an approach needs adequate physical AND chemical modeling of the disk. I will present results on the thermal and chemical structure of protoplanetary disks and describe how suitable gas tracers will be indentified and model predictions will be tested using current and future obervations. First results indicate that systems in later evolutionary stages of planet formation still contain enough gas to influence the dust dynamics in the disk.