The Observability of Vortex-driven Spiral Arms in Protoplanetary Disks: Basic Spiral Properties
Abstract
Some circumstellar disks are observed to show prominent spiral arms in infrared scattered light or (sub-)millimeter dust continuum. The spirals might be formed from self-gravity, shadows, or planet-disk interactions. Recently, it was hypothesized that massive vortices can drive spiral arms in protoplanetary disks in a way analogous to planets. In this paper, we study the basic properties of vortex-driven spirals by the Rossby Wave Instability in 2D hydrodynamics simulations. We study how the surface density contrast, the number, and the shape of vortex-driven spirals depend on the properties of the vortex. We also compare vortex-driven spirals with those induced by planets. The surface density contrast of vortex-driven spirals in our simulations are comparable to those driven by a sub-thermal mass planet, typically a few to a few tens of Earth masses. In addition, different from the latter, the former is not sensitive to the mass of the vortex. Vortex-driven spiral arms are not expected to be detectable in current scattered light observations, and the prominent spirals observed in scattered light in a few protoplanetary disks, such as SAO 206462 (HD 135344B), MWC 758, and LkHα 330, are unlikely to be induced by the candidate vortices in them.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- October 2019
- DOI:
- 10.3847/2041-8213/ab40c4
- arXiv:
- arXiv:1909.00706
- Bibcode:
- 2019ApJ...883L..39H
- Keywords:
-
- Hydrodynamics;
- Hydrodynamical simulations;
- Planet formation;
- Protoplanetary disks;
- 1963;
- 767;
- 1241;
- 1300;
- Astrophysics - Earth and Planetary Astrophysics
- E-Print:
- 8 pages, 4 figures, Astrophysical Journal Letters accepted