Radial mixing in protoplanetary accretion disks

II. Time dependent disk models with annealing and carbon combustion

Institut für Theoretische Astrophysik, Universität Heidelberg, Tiergartenstraße 15, 69121 Heidelberg, Germany e-mail: gail@ita.uni-heidelberg.de

Corresponding author: M. Wehrstedt, mwehrste@ita.uni-heidelberg.de

Received: 12 November 2001
Accepted: 14 January 2002

Abstract

This work investigates the annealing of silicate dust, the combustion of carbon dust and radial mixing of both dust species within protoplanetary disks. For this purpose the diffusion-transport-reaction equations of both dust species (including annealing of silicate and carbon combustion) are simultaneously solved with the equations for the global evolution of an α-disk within an one-zone, time-dependent numerical model. The protostar-disk system is assumed to be in a quiescent stage which corresponds with the class II phase of evolution of star-disk systems. The results suggest that the diffusive transport spreads the dust globally throughout the disk, and therefore provides an explanation for the existence of crystalline silicate and methane within the primordial bodies of the solar system.