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Streaming instability of multiple particle species in protoplanetary disks

Schaffer, Noemi LU ; Yang, Chao Chin LU and Johansen, Anders LU (2018) In Astronomy and Astrophysics 618.
Abstract

The radial drift and diffusion of dust particles in protoplanetary disks affect both the opacity and temperature of such disks, as well as the location and timing of planetesimal formation. In this paper, we present results of numerical simulations of particle-gas dynamics in protoplanetary disks that include dust grains with various size distributions. We have considered three scenarios in terms of particle size ranges, one where the Stokes number τs = 10-1-100, one where τs = 10-4-10-1, and finally one where τs = 10-3-100. Moreover, we considered both discrete and continuous distributions in particle size. In accordance with previous... (More)

The radial drift and diffusion of dust particles in protoplanetary disks affect both the opacity and temperature of such disks, as well as the location and timing of planetesimal formation. In this paper, we present results of numerical simulations of particle-gas dynamics in protoplanetary disks that include dust grains with various size distributions. We have considered three scenarios in terms of particle size ranges, one where the Stokes number τs = 10-1-100, one where τs = 10-4-10-1, and finally one where τs = 10-3-100. Moreover, we considered both discrete and continuous distributions in particle size. In accordance with previous works we find in our multispecies simulations that different particle sizes interact via the gas and as a result their dynamics changes compared to the single-species case. The larger species trigger the streaming instability and create turbulence that drives the diffusion of the solid materials. We measured the radial equilibrium velocity of the system and find that the radial drift velocity of the large particles is reduced in the multispecies simulations and that the small particle species move on average outwards. We also varied the steepness of the size distribution, such that the exponent of the solid number density distribution, dNâda âa-q, is either q = 3 or q = 4. Overall, we find that the steepness of the size distribution and the discrete versus continuous approach have little impact on the results. The level of diffusion and drift rates are mainly dictated by the range of particle sizes. We measured the scale height of the particles and observe that small grains are stirred up well above the sedimented midplane layer where the large particles reside. Our measured diffusion and drift parameters can be used in coagulation models for planet formation as well as to understand relative mixing of the components of primitive meteorites (matrix, chondrules and CAIs) prior to inclusion in their parent bodies.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Diffusion, Hydrodynamics, Instabilities, Methods: numerical, Protoplanetary disks, Turbulence
in
Astronomy and Astrophysics
volume
618
article number
A75
publisher
EDP Sciences
external identifiers
  • scopus:85055202211
ISSN
0004-6361
DOI
10.1051/0004-6361/201832783
language
English
LU publication?
yes
id
b0c1305f-93d8-421d-81a5-fb867a7bf06c
date added to LUP
2018-11-16 08:30:34
date last changed
2020-01-22 07:19:32
@article{b0c1305f-93d8-421d-81a5-fb867a7bf06c,
  abstract     = {<p>The radial drift and diffusion of dust particles in protoplanetary disks affect both the opacity and temperature of such disks, as well as the location and timing of planetesimal formation. In this paper, we present results of numerical simulations of particle-gas dynamics in protoplanetary disks that include dust grains with various size distributions. We have considered three scenarios in terms of particle size ranges, one where the Stokes number τ<sub>s</sub> = 10<sup>-1</sup>-10<sup>0</sup>, one where τ<sub>s</sub> = 10<sup>-4</sup>-10<sup>-1</sup>, and finally one where τ<sub>s</sub> = 10<sup>-3</sup>-10<sup>0</sup>. Moreover, we considered both discrete and continuous distributions in particle size. In accordance with previous works we find in our multispecies simulations that different particle sizes interact via the gas and as a result their dynamics changes compared to the single-species case. The larger species trigger the streaming instability and create turbulence that drives the diffusion of the solid materials. We measured the radial equilibrium velocity of the system and find that the radial drift velocity of the large particles is reduced in the multispecies simulations and that the small particle species move on average outwards. We also varied the steepness of the size distribution, such that the exponent of the solid number density distribution, dNâda âa<sup>-q</sup>, is either q = 3 or q = 4. Overall, we find that the steepness of the size distribution and the discrete versus continuous approach have little impact on the results. The level of diffusion and drift rates are mainly dictated by the range of particle sizes. We measured the scale height of the particles and observe that small grains are stirred up well above the sedimented midplane layer where the large particles reside. Our measured diffusion and drift parameters can be used in coagulation models for planet formation as well as to understand relative mixing of the components of primitive meteorites (matrix, chondrules and CAIs) prior to inclusion in their parent bodies.</p>},
  author       = {Schaffer, Noemi and Yang, Chao Chin and Johansen, Anders},
  issn         = {0004-6361},
  language     = {eng},
  publisher    = {EDP Sciences},
  series       = {Astronomy and Astrophysics},
  title        = {Streaming instability of multiple particle species in protoplanetary disks},
  url          = {http://dx.doi.org/10.1051/0004-6361/201832783},
  doi          = {10.1051/0004-6361/201832783},
  volume       = {618},
  year         = {2018},
}