期刊
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
卷 489, 期 1, 页码 325-338出版社
OXFORD UNIV PRESS
DOI: 10.1093/mnras/stz2128
关键词
instabilities; turbulence; planets and satellites: formation; ISM: kinematics and dynamics; galaxies: formation
资金
- Alfred P. Sloan Research Fellowship
- National Science Foundation [1715847, 1455342, TG-AST130039, PRAC NSF.1713353]
- National Aeronautics and Space Administration [TG-AST130039, PRAC NSF.1713353, NNX15AT06G, JPL 1589742, 17-ATP17-0214, HEC SMD-16-7592]
- Royal Society Te Aparangi [RDF-U001804, UOO1727]
- Direct For Mathematical & Physical Scien
- Division Of Astronomical Sciences [1715847] Funding Source: National Science Foundation
- Division Of Astronomical Sciences
- Direct For Mathematical & Physical Scien [1455342] Funding Source: National Science Foundation
We study the non-linear evolution of the acoustic 'resonant drag instability' (RDI) using numerical simulations. The acoustic RDI is excited in a dust-gas mixture when dust grains stream through gas, interacting with sound waves to cause a linear instability. We study this process in a periodic box by accelerating neutral dust with an external driving force. The instability grows as predicted by linear theory, eventually breaking into turbulence and saturating. As in linear theory, the non-linear behaviour is characterized by three regimes high, intermediate, and low wavenumbers- the boundary between which is determined by the dust-gas coupling strength and the dust-to-gas mass ratio. The high and intermediate wavenumber regimes behave similarly to one another, with large dust-to-gas ratio fluctuations while the gas remains largely incompressible. The saturated state is highly anisotropic: dust is concentrated in filaments, jets, or plumes along the direction of acceleration, with turbulent vortex-like structures rapidly forming and dissipating in the perpendicular directions. The low-wavenumber regime exhibits large fluctuations in gas and dust density, but the dust and gas remain more strongly coupled in coherent 'fronts' perpendicular to the acceleration. These behaviours are qualitatively different from those of dust `passively' driven by external hydrodynamic turbulence, with no back-reaction force from dust on to gas. The virulent nature of these instabilities has interesting implications for dust-driven winds in a variety of astrophysical systems, including around cool stars, in dusty torii around active-galactic-nuclei, and in and around giant molecular clouds.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据