Inhibited Coagulation of Micron-size Dust Due to the Electrostatic Barrier

Abstract

The collisional evolution of solid material in protoplanetary disks is a crucial step in the formation of planetesimals, comets, and planets. Although dense protoplanetary environments favor fast dust coagulation, there are several factors that limit the straightforward pathway from interstellar micron-size grains to pebble-size aggregates. Apart from the grain bouncing, fragmentation, and fast drift to the central star, a notable limiting factor is the electrostatic repulsion of like-charged grains. In this study we aim at theoretical modeling of the dust coagulation coupled with the dust charging and disk ionization calculations. We show that the electrostatic barrier is a strong restraining factor to the coagulation of micrometer-size dust in dead zones of the disk (where the turbulence is suppressed). While the sustained turbulence helps to overcome the electrostatic barrier, low fractal dimensions of dust aggregates can potentially block their further coagulation even in this case. Coulomb repulsion may keep a significant fraction of small dust in the disk atmosphere and outer regions.

accepted for publication in ApJ

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Cited by in corpus (12)

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• Dust grains cannot grow to millimeter sizes in protostellar envelopes
• The growth of super-large pre-planetary pebbles to an impact erosion limit
• Coagulation-Fragmentation Equilibrium for Charged Dust: Abundance of Submicron Grains Increases Dramatically in Protoplanetary Disks
• Radiative transfer of ionizing radiation through gas and dust: grain charging in star forming regions
• Dust evolution during the protostellar collapse: influence on the coupling between the neutral gas and the magnetic field
• Ionization chemistry in the inner disc: a combined treatment of ionic and thermionic emission and arbitrary grain size distributions
• Ionizing Protoplanetary Disks in Pebble Collisions
• Dust enrichment and growth in the earliest stages of protoplanetary disk formation
• A fast tree algorithm for multi-component coagulation equation