PARTICLE CONCENTRATION AT PLANET-INDUCED GAP EDGES AND VORTICES. I. INVISCID THREE-DIMENSIONAL HYDRO DISKS

We perform a systematic study of the dynamics of dust particles in protoplanetary disks with embedded planets using global two-dimensional and three-dimensional inviscid hydrodynamic simulations. Lagrangian particles have been implemented into the magnetohydrodynamic code Athena with cylindrical coordinates. We find two distinct outcomes depending on the mass of the embedded planet. In the presence of a low-mass planet (8M.), two narrow gaps start to open in the gas on each side of the planet where the density waves are shocked. These shallow gaps can dramatically affect particle drift speed and cause significant, roughly axisymmetric dust depletion. On the other hand, a more massive planet (> 0.1MJ) carves out a deeper gap with sharp edges, which are subject to Rossby wave instability leading to vortex formation. Particles with a wide range of sizes (0.02 < Omega ts < 20) are trapped and settle to the midplane in the vortex, with the strongest concentration for particles with Omega ts similar to 1. The dust concentration is highly elongated in the f direction, and can be as wide as four disk scale heights in the radial direction. Dust surface density inside the vortex can be increased by more than a factor of 10(2) in a very non-axisymmetric fashion. For very big particles (Omega ts >> 1) we find strong eccentricity excitation, in particular around the planet and in the vicinity of the mean motion resonances, facilitating gap openings there. Our results imply that in weakly turbulent protoplanetary disk regions (e. g., the "dead zone") dust particles with a very wide range of sizes can be trapped at gap edges and inside vortices induced by planets with M-p < M-J, potentially accelerating planetesimal and planet formation there, and giving rise to distinctive features that can be probed by ALMA and the Extended Very Large Array.