DUST DYNAMICS IN PROTOPLANETARY DISK WINDS DRIVEN BY MAGNETOROTATIONAL TURBULENCE: A MECHANISM FOR FLOATING DUST GRAINS WITH CHARACTERISTIC SIZES

Abstract Relatively large dust grains (referred to as pebbles) accumulate at the outer edge of the gap induced by a planet in a protoplanetary disk, and a ring structure with a high dust-to-gas ratio can be formed. Such a ring has been thought to be located immediately outside the planetary orbit. We examined the evolution of the dust ring formed by a migrating planet, by performing two-fluid (gas and dust) hydrodynamic simulations. We found that the initial dust ring does not follow the migrating planet and remains at the initial location of the planet in cases with a low viscosity of α ∼ 10−4. The initial ring is gradually deformed by viscous diffusion, and a new ring is formed in the vicinity of the migrating planet, which develops from the trapping of the dust grains leaking from the initial ring. During this phase, two rings coexist outside the planetary orbit. This phase can continue over ∼1 Myr for a planet migrating from 100 au. After the initial ring disappears, only the later ring remains. This change in the ring morphology can provide clues as to when and where the planet was formed, and is the footprint of the planet. We also carried out simulations with a planet growing in mass. These simulations show more complex asymmetric structures in the dust rings. The observed asymmetric structures in the protoplanetary disks may be related to a migrating and growing planet.

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Interaction between single dust grains and ions or electrons: laboratory measurements and their consequences for the dust dynamics

Faraday Discussions ◽

10.1039/b702843a ◽

2008 ◽

Vol 137 ◽

pp. 139-155 ◽

Cited By ~ 27

Author(s):

Jiří Pavlů ◽

Ivana Richterová ◽

Zdeněk Němeček ◽

Jana Šafránková ◽

Ivo Čermák

Keyword(s):

Dust Grains ◽

Laboratory Measurements ◽

Dust Dynamics

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Interplanetary dust delivery of water to the atmospheres of Pluto and Triton

Astronomy and Astrophysics ◽

10.1051/0004-6361/201833980 ◽

2018 ◽

Vol 617 ◽

pp. L5 ◽

Cited By ~ 1

Author(s):

A. R. Poppe ◽

M. Horányi

Keyword(s):

Interplanetary Dust ◽

Minor Role ◽

Dust Grains ◽

Water Ice ◽

Significant Difference ◽

Meteoric Smoke ◽

Dust Dynamics ◽

The Individual ◽

A Minor ◽

Interplanetary Dust Particle

Context. Both Pluto and Triton possess thin, N2-dominated atmospheres controlled by sublimation of surface ices. Aims. We aim to constrain the influx and ablation of interplanetary dust grains into the atmospheres of both Pluto and Triton in order to estimate the rate at which oxygen-bearing species are introduced into both atmospheres. Methods. We use (i) an interplanetary dust dynamics model to calculate the flux and velocity distributions of interplanetary dust grains relevant for both Pluto and Triton and (ii) a model for the ablation of interplanetary dust grains in the atmospheres of both Pluto and Triton. We sum the individual ablation profiles over the incoming mass and velocity distributions of interplanetary dust grains in order to determine the vertical structure and net deposition of water to both atmospheres. Results. Our results show that <2% of silicate grains ablate at either Pluto or Triton while approximately 75% and >99% of water ice grains ablate at Pluto and Triton, respectively. From ice grains, we calculate net water influxes to Pluto and Triton of ~3.8 kg day−1 (8.5 × 103 H2O cm−2 s−1) and ~370 kg day−1 (6.2 × 105 H2O cm−2 s−1), respectively. The significant difference in total water deposition between Pluto and Triton is due to the presence of Triton within Neptune’s gravity well, which both enhances interplanetary dust particle (IDP) fluxes due to gravitational focusing and accelerates grains before entry into Triton’s atmosphere, thereby causing more efficient ablation. Conclusions. We conclude that water deposition from dust ablation plays only a minor role at Pluto due to its relatively low flux. At Triton, water deposition from IDPs is more significant and may play a role in the alteration of atmospheric and ionospheric chemistry. We also suggest that meteoric smoke and smaller, unablated grains may serve as condensation nuclei for the formation of hazes at both worlds.

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