Abstract
Oxygen isotopic heterogeneity among chondritic constituents (16O-rich CAIs and 16O-poor chondrules) reflects evolution in oxygen isotopic composition of the inner solar nebula gas. Yurimoto and Kuramoto (2004) have suggested that the oxygen isotopic evolution at the inner nebula was induced by subsequent enhancement of 16O-depleted H2O which produced by photochemical process in the parent molecular cloud. In their model, the excess H2O was supplied from outer part of the nebula with inward migration of ice-covered dust particles and evaporation of the icy mantle. However, they did not consider migration of silicate dust particles which apparently result in depletion of chondrule precursors.
In this study, we perform a numerical simulation of radial transport of H2O and silicate in a turbulent protoplanetary disk considering difference in adhesive properties between H2O ice and silicate. As a result, sticky ice-covered dust particles grow up to ~cm and efficiently migrate inward supplying excess water vapor to the inner nebula, while small (~sub-mm) silicate particles are well coupled to the nebula gas and retained in the inner nebula over ~Myr.
