The Kelvin-Helmholtz interface instability in the interstellar environment. I. The morphology of the Corona Australis dark cloud complex.
Abstract
Certain morphological features of the CrA dark cloud complex, such as the wrinkled extinction contours and the regular spacing of four dust clouds along the northern boundary of the complex, are identified with the Kelvin-Helmholtz instability produced by hydrodynamic drag at the boundary as the complex falls into the galactic plane. The range of unstable wavelengths is estimated to be 2 ⪉ Λ (pc) ⪉ 5, consistent with the observed projected spacing ≡3 pc of the dust clouds. It is suggested that the dust in CrA accumulates via a Parker instability in the regularly spaced magnetic wells within the complex at points (determined by the wavelength of the unstable Kelvin-Helmholtz modes) of minimum cloud gravitational potential.
- Publication:
-
The Astronomical Journal
- Pub Date:
- April 1984
- DOI:
- 10.1086/113542
- Bibcode:
- 1984AJ.....89..506F
- Keywords:
-
- Cosmic Dust;
- Interstellar Matter;
- Kelvin-Helmholtz Instability;
- Molecular Clouds;
- Spatial Distribution;
- Gravitational Fields;
- Morphology;
- Astrophysics