On the Crystallinity of Silicate Dust in Evolving Protoplanetary Disks due to Magnetically Driven Disk Winds

Abstract

We present a novel mechanism for the outward transport of crystalline dust particles: the outward radial drift of pebbles. A dust-ring structure is frequently observed in protoplanetary disks. One of the plausible mechanisms for the formation of dust rings is the accumulation of pebbles around the pressure maximum, which is formed by the mass loss due to magnetically driven disk winds. Due to magnetically driven disk winds, dust particles in evolving protoplanetary disks can migrate outwardly from the crystallization front to the pressure maximum by radial drift. We found that the outward radial drift process can transport crystalline dust particles efficiently when the radial drift timescale is shorter than the advection timescale. Our model predicts that the crystallinity of silicate dust particles could be as high as 100% inside the dust-ring position.