The vertical shear instability in poorly ionized, magnetized protoplanetary discs
View / Open Files
Authors
Latter, HN
Kunz, MW
Publication Date
2022Journal Title
Monthly Notices of the Royal Astronomical Society
ISSN
0035-8711
Publisher
Oxford University Press (OUP)
Type
Article
This Version
AM
Metadata
Show full item recordCitation
Latter, H., & Kunz, M. (2022). The vertical shear instability in poorly ionized, magnetized protoplanetary discs. Monthly Notices of the Royal Astronomical Society https://doi.org/10.1093/mnras/stac107
Abstract
Protoplanetary discs should exhibit a weak vertical variation in their
rotation profiles. Typically this `vertical shear' issues from a baroclinic
effect driven by the central star's radiation field, but it might also arise
during the launching of a magnetocentrifugal wind. As a consequence,
protoplanetary discs are subject to a hydrodynamical instability, the `vertical
shear instability' (VSI), whose breakdown into turbulence could transport a
moderate amount of angular momentum and facilitate, or interfere with, the
process of planet formation. Magnetic fields may suppress the VSI, however,
either directly via magnetic tension or indirectly through magnetorotational
turbulence. On the other hand, protoplanetary discs exhibit notoriously low
ionisation fractions, and non-ideal effects, if sufficiently dominant, may come
to the VSI's rescue. In this paper we develop a local linear theory that
explores how non-ideal MHD influences the VSI, while also launching additional
diffusive shear instabilities. We derive a set of analytical criteria that
establish when the VSI prevails, and then show how it can be applied to a
realistic global model of a protoplanetary disc. Our calculations suggest that
within ~10au the VSI should have little trouble emerging in the main body of
the disk, but beyond that, and in the upper regions of the disc, its onset
depends sensitively on the size of the preponderant dust grains.
Keywords
astro-ph.EP, astro-ph.EP, astro-ph.SR
Identifiers
External DOI: https://doi.org/10.1093/mnras/stac107
This record's URL: https://www.repository.cam.ac.uk/handle/1810/333729
Rights
Publisher's own licence
Statistics
Total file downloads (since January 2020). For more information on metrics see the
IRUS guide.