Christine Chen (STScI) : The Origin and Evolution of Dust and Gas in Debris Disks

Debris disks are dusty, gas-poor disks around young stars, generated by collisions between parent bodies and/or sublimation of comets. The Spitzer Space Telescope has enabled photometric searches and detailed spectroscopic studies of thermal emission from dust in hundreds of debris disks at mid- to far-infrared wavelengths. These observations allow us to (1) to measure the disk fraction (in young associations and moving groups) as a function of mass and age to constrain the dust production and dissipation mechanisms, and (2) infer the spatial structure of dust in individual systems and therefore the presence of companions. In this talk, I will discuss the spatial structure and removal mechanisms of dust in debris disks, and constraints on the models of the formation of terrestrial planets and the late-stages of solar system evolution. I will also describe outstanding questions about planetary system evolution that can not be addressed with Spitzer and will require future ground- and space-based instruments.