Characterizing the variable dust permeability of planet-induced gaps.
Aerodynamic theory predicts that dust grains in protoplanetary disks will drift inward on comparatively short timescales. In this paper, we re-investigate how the presence of a gap-opening planet influences this rapid radial transport of dust, and we aim to characterize the permeability of the gap as a function of particle size and for various external parameters. To this end, we perform long-term hydrodynamical simulations in two dimensions, including different dust species treated as pressureless fluids. We initialize the dust outside of the planet's orbit and study under which conditions dust grains are able to cross the gap carved by the planet. In agreement with previous work, we find that the permeability of the gap depends both on dust- and disk properties: while small dust follows the viscously accreting gas through the gap, dust grains approaching a critical size are progressively filtered out. Specifically, higher viscosity, smaller planet mass, or a more massive disk can shift this critical size to larger values. Our results indicate that gap-opening planets may act to deplete the inner reaches of protoplanetary disks of large dust grains -- potentially limiting the accretion of solids onto forming terrestrial planets. We finally propose a test of whether this scenario might have contributed to shaping the Solar System, namely by comparing the size distributions of Calcium-Aluminum-rich inclusions and chondrules of isotopically different parent bodies with one another.
Publisher URL: http://arxiv.org/abs/1801.07971