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The coexistence of the streaming instability and the vertical shear instability in protoplanetary disks : Scale dependence of dust diffusion

Schäfer, Urs ; Johansen, Anders LU and Flock, Mario (2025) In Astronomy and Astrophysics 694.
Abstract

The vertical shear instability and the streaming instability are two robust sources of turbulence in protoplanetary disks. The former has been found to induce anisotropic turbulence that is stronger in the vertical than in the radial dimension and to be overall stronger compared to the largely isotropic turbulence caused by the streaming instability. In this study, we shed light on the dust diffusion by the vertical shear instability and the streaming instability separately and together, and in particular on the direction- and scale-dependence of the diffusion. To this end, we employ two-dimensional global models of the two instabilities either in isolation or in combination. The vertical shear instability in isolation diffuses dust... (More)

The vertical shear instability and the streaming instability are two robust sources of turbulence in protoplanetary disks. The former has been found to induce anisotropic turbulence that is stronger in the vertical than in the radial dimension and to be overall stronger compared to the largely isotropic turbulence caused by the streaming instability. In this study, we shed light on the dust diffusion by the vertical shear instability and the streaming instability separately and together, and in particular on the direction- and scale-dependence of the diffusion. To this end, we employ two-dimensional global models of the two instabilities either in isolation or in combination. The vertical shear instability in isolation diffuses dust more strongly in the vertical direction than the streaming instability in isolation, resulting in a wave-shaped dust layer in our two-dimensional simulations. Compared with this large-scale diffusion, though, our study highlights that the vertical shear instability causes substantially weaker or even negligible small-scale diffusion. We validate this result using previously published three-dimensional simulations. In particular when simulating centimetre-sized dust, the undulating dust layer becomes internally razor-thin. In contrast, the diffusion owing to the streaming instability exhibits only a marginal scaledependence, with the dust layer possessing a Gaussian shape. In models including both instabilities, the undulating mid-plane layer is broadened to a width set by the intrinsic diffusion level caused by the streaming instability.

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type
Contribution to journal
publication status
published
subject
keywords
Hydrodynamics, Instabilities, Methods: numerical, Protoplanetary disks, Turbulence
in
Astronomy and Astrophysics
volume
694
article number
A57
publisher
EDP Sciences
external identifiers
  • scopus:85217029928
ISSN
0004-6361
DOI
10.1051/0004-6361/202453439
language
English
LU publication?
yes
additional info
Publisher Copyright: © 2025 EDP Sciences. All rights reserved.
id
ef4ca7bb-1774-4001-b286-94b86461c836
date added to LUP
2025-03-27 16:13:00
date last changed
2025-04-04 14:33:20
@article{ef4ca7bb-1774-4001-b286-94b86461c836,
  abstract     = {{<p>The vertical shear instability and the streaming instability are two robust sources of turbulence in protoplanetary disks. The former has been found to induce anisotropic turbulence that is stronger in the vertical than in the radial dimension and to be overall stronger compared to the largely isotropic turbulence caused by the streaming instability. In this study, we shed light on the dust diffusion by the vertical shear instability and the streaming instability separately and together, and in particular on the direction- and scale-dependence of the diffusion. To this end, we employ two-dimensional global models of the two instabilities either in isolation or in combination. The vertical shear instability in isolation diffuses dust more strongly in the vertical direction than the streaming instability in isolation, resulting in a wave-shaped dust layer in our two-dimensional simulations. Compared with this large-scale diffusion, though, our study highlights that the vertical shear instability causes substantially weaker or even negligible small-scale diffusion. We validate this result using previously published three-dimensional simulations. In particular when simulating centimetre-sized dust, the undulating dust layer becomes internally razor-thin. In contrast, the diffusion owing to the streaming instability exhibits only a marginal scaledependence, with the dust layer possessing a Gaussian shape. In models including both instabilities, the undulating mid-plane layer is broadened to a width set by the intrinsic diffusion level caused by the streaming instability.</p>}},
  author       = {{Schäfer, Urs and Johansen, Anders and Flock, Mario}},
  issn         = {{0004-6361}},
  keywords     = {{Hydrodynamics; Instabilities; Methods: numerical; Protoplanetary disks; Turbulence}},
  language     = {{eng}},
  month        = {{02}},
  publisher    = {{EDP Sciences}},
  series       = {{Astronomy and Astrophysics}},
  title        = {{The coexistence of the streaming instability and the vertical shear instability in protoplanetary disks : Scale dependence of dust diffusion}},
  url          = {{http://dx.doi.org/10.1051/0004-6361/202453439}},
  doi          = {{10.1051/0004-6361/202453439}},
  volume       = {{694}},
  year         = {{2025}},
}