SELF-DESTRUCTING SPIRAL WAVES: GLOBAL SIMULATIONS OF A SPIRAL-WAVE INSTABILITY IN ACCRETION DISKS

Journal Article · Tue Sep 20 04:00:00 EDT 2016 · Astrophysical Journal

DOI:https://doi.org/10.3847/0004-637X/829/1/13· OSTI ID:22667428

Bae, Jaehan; Hartmann, Lee ^[1]; Nelson, Richard P.; Richard, Samuel ^[2]

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1. Department of Astronomy, University of Michigan, 1085 S. University Ave., Ann Arbor, MI 48109 (United States)
2. Astronomy Unit, Queen Mary University of London, Mile End Road, London E1 4NS (United Kingdom)

We present results from a suite of three-dimensional global hydrodynamic simulations that shows that spiral density waves propagating in circumstellar disks are unstable to the growth of a parametric instability that leads to break down of the flow into turbulence. This spiral wave instability (SWI) arises from a resonant interaction between pairs of inertial waves, or inertial-gravity waves, and the background spiral wave. The development of the instability in the linear regime involves the growth of a broad spectrum of inertial modes, with growth rates on the order of the orbital time, and results in a nonlinear saturated state in which turbulent velocity perturbations are of a similar magnitude to those induced by the spiral wave. The turbulence induces angular momentum transport and vertical mixing at a rate that depends locally on the amplitude of the spiral wave (we obtain a stress parameter α ∼ 5 × 10{sup −4} in our reference model). The instability is found to operate in a wide range of disk models, including those with isothermal or adiabatic equations of state, and in viscous disks where the dimensionless kinematic viscosity ν ≤ 10{sup −5}. This robustness suggests that the instability will have applications to a broad range of astrophysical disk-related phenomena, including those in close binary systems, planets embedded in protoplanetary disks (including Jupiter in our own solar system) and FU Orionis outburst models. Further work is required to determine the nature of the instability and to evaluate its observational consequences in physically more complete disk models than we have considered in this paper.

• OSTI ID: 22667428
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 829; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ACCRETION DISKS
ANGULAR MOMENTUM
ASTROPHYSICS
DENSITY
DISTURBANCES
EQUATIONS OF STATE
GRAVITATION
GRAVITY WAVES
HYDRODYNAMIC MODEL
JUPITER PLANET
PARAMETRIC INSTABILITIES
PERTURBATION THEORY
PROTOPLANETS
SIMULATION
SOLAR SYSTEM
SPECTRA
THREE-DIMENSIONAL CALCULATIONS
TURBULENCE
VELOCITY
VISCOSITY