Non-linear evolution of the resonant drag instability in magnetized gas
Abstract
We investigate, for the first time, the non-linear evolution of the magnetized 'resonant drag instabilities' (RDIs). We explore magnetohydrodynamic simulations of gas mixed with (uniform) dust grains subject to Lorentz and drag forces, using the GIZMO code. The magnetized RDIs exhibit fundamentally different behaviour than purely acoustic RDIs. The dust organizes into coherent structures and the system exhibits strong dust–gas separation. In the linear and early non-linear regime, the growth rates agree with linear theory and the dust self-organizes into 2D planes or 'sheets.' Eventually the gas develops fully non-linear, saturated Alfvénic, and compressible fast-mode turbulence, which fills the underdense regions with a small amount of dust, and drives a dynamo that saturates at equipartition of kinetic and magnetic energy. The dust density fluctuations exhibit significant non-Gaussianity, and the power spectrum is strongly weighted towards the largest (box scale) modes. The saturation level can be understood via quasi-linear theory, as the forcing and energy input via the instabilities become comparable to saturated tension forces and dissipation in turbulence. The magnetized simulation presented here is just one case; it is likely that the magnetic RDIs can take many forms in different parts of parameter space.
Additional Information
© 2019 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society. This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model). Accepted 2019 February 27. Received 2019 February 1; in original form 2018 October 2. Published: 07 March 2019. This work was initiated as part of the Kavli Summer Program in Astrophysics, hosted at the Center for Computational Astrophysics at the Flatiron Institute in New York. We thank the Kavli Foundation and the Simons Foundation, for their support. DS thanks Fred Adams, Andrea Ferrara, and Daniel Lecoanet for insightful comments and suggestions that significantly contributed to this work. Support for PFH was provided by an Alfred P. Sloan Research Fellowship, Natioinal Science Foundation (NSF) Collaborative Research grant #1715847 and CAREER grant #1455342, and NASA grants NNX15AT06G, JPL 1589742, 17-ATP17-0214. Numerical calculations were run on the Caltech compute cluster 'Wheeler,' allocations from XSEDE TG-AST130039 and PRAC NSF.1713353 supported by the NSF, and NASA HEC SMD-16-7592. We thank the referee for a comprehensive report that strengthened the overall scientific content of the paper.Attached Files
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Additional details
- Alternative title
- Nonlinear Evolution of the Resonant Drag Instability in Magnetized Gas
- Eprint ID
- 92724
- Resolver ID
- CaltechAUTHORS:20190206-105617834
- Kavli Foundation
- Simons Foundation
- Alfred P. Sloan Foundation
- NSF
- AST-1715847
- NSF
- AST-1455342
- NASA
- NNX15AT06G
- JPL
- 1589742
- JPL
- 17-ATP17-0214
- NSF
- TG-AST130039
- NSF
- OAC-1713353
- NASA
- SMD-16-7592
- Created
-
2019-02-08Created from EPrint's datestamp field
- Updated
-
2021-11-16Created from EPrint's last_modified field
- Caltech groups
- TAPIR, Astronomy Department