Photophoretic Structuring of Circumstellar Dust Disks

Abstract

We study dust accumulation by photophoresis in optically thin gas disks. Using formulae for the photophoretic force that are applicable for the free molecular regime and for the slip-flow regime, we calculate dust accumulation distances as a function of particle size. It is found that photophoresis pushes particles (smaller than 10 cm) outward. For a Sun-like star, these particles are transported to 0.1-100 AU, depending on their size, and form an inner disk. Radiation pressure pushes small particles (