The Drag Instability in a 1D Isothermal C-Shock

Abstract

We investigate whether the drag instability, proposed by Gu et al., occurs in a one-dimensional (1D) C-shock. The 1D background model proposed by Chen and Ostriker for a steady isothermal C-shock is adopted, and a 1D isothermal linear analysis is performed. We confirm the postulation of Gu et al. that the drift velocity between the ions and the neutrals is sufficiently high within a C-shock to allow for the drag instability. We also study the underlying physics of the decaying modes in the shock and post-shock regions. The drag instability is an overstability phenomenon associated with an exponentially growing mode of a propagating wave. We find that the growing wave mode can only propagate downstream within the shock and subsequently decay in the post-shock region. The maximum total growth (MTG) for such an unstable wave before it is damped is estimated in typical environments of star-forming clouds, which is approximately 10-30 times larger than the initial perturbation at the modest shock velocities and can be significantly enhanced several hundred times for a stronger C-shock with a larger width.

arXiv comment18 pages, 8 figures, ApJ in press

References in corpus (44)

• Theory of Star Formation
• Streaming Instabilities in Protoplanetary Disks
• Athena: A New Code for Astrophysical MHD
• Re-examining Larson's Scaling Relationships in Galactic Molecular Clouds
• Regulation of Star Formation Rates in Multiphase Galactic Disks: a Thermal/Dynamical Equilibrium Model
• Investigating the Cosmic-Ray Ionization Rate in the Galactic Diffuse Interstellar Medium through Observations of H3+
• A new Jeans resolution criterion for (M)HD simulations of self-gravitating gas: Application to magnetic field amplification by gravity-driven turbulence
• Global simulations of protoplanetary disks with ohmic resistivity and ambipolar diffusion
• Thanatology in Protoplanetary Discs: the combined influence of Ohmic, Hall, and ambipolar diffusion on dead zones
• Star Formation Relations in Nearby Molecular Clouds
• SiO line emission from C-type shock waves : interstellar jets and outflows
• Kinetic and Structural Evolution of Self-gravitating, Magnetized Clouds: 2.5-Dimensional Simulations of Decaying Turbulence
• Effect of Ambipolar Diffusion on the Non-linear Evolution of Magnetorotational Instability in Weakly Ionized Disks
• Mechanism of Magnetic Flux Loss in Molecular Clouds
• Ambipolar diffusion in low-mass star formation. I. General comparison with the ideal MHD case
• Magnetic Braking and Protostellar Disk Formation: Ambipolar Diffusion
• The formation of rings and gaps in magnetically coupled disk-wind systems: ambipolar diffusion and reconnection
• Bridging the gap: disk formation in the Class 0 phase with ambipolar diffusion and Ohmic dissipation
• Magnetically self-regulated formation of early protoplanetary discs
• Formation of Magnetized Prestellar Cores with Ambipolar Diffusion and Turbulence
• Protostellar birth with ambipolar and ohmic diffusion
• Probing the Turbulence Dissipation Range and Magnetic Field Strengths in Molecular Clouds
• Dust settling and rings in the outer regions of protoplanetary discs subject to ambipolar diffusion
• GMC Evolutions in the Nearby Spiral Galaxy M33
• Giant molecular clouds and massive star formation in the southern milky way
• The formation of rings and gaps in wind-launching non-ideal MHD disks: three-dimensional simulations
• Sub-Alfvenic Non-Ideal MHD Turbulence Simulations with Ambipolar Diffusion: II. Comparison with Observation, Clump Properties, and Scaling to Physical Units
• Sub-Alfvenic Non-Ideal MHD Turbulence Simulations with Ambipolar Diffusion: I. Turbulence Statistics
• The Inability of Ambipolar Diffusion to set a Characteristic Mass Scale in Molecular Clouds
• Origin of CH+ in diffuse molecular clouds warm H2 and ion-neutral drift
• Disk Formation in Magnetized Dense Cores with Turbulence and Ambipolar Diffusion
• Nonlinear Development and Observational Consequences of Wardle C-Shock Instabilities
• The scaling relations and star formation laws of ministarburst complexes
• The Wardle Instability in Interstellar Shocks: I. Nonlinear Dynamical Evolution
• Time-Dependent, Multifluid, Magnetohydrodynamic Shock Waves with Grain Dynamics I. Formulation and Numerical Tests
• Observational Determination of the Turbulent Ambipolar Diffusion Scale and Magnetic Field Strength in Molecular Clouds
• Ambipolar Diffusion in Action: Transient C shock Structure and Prestellar Core Formation
• CH as a Molecular Gas Tracer and C-Shock Tracer Across a Molecular Cloud Boundary in Taurus
• Signatures of fast and slow magnetohydrodynamic shocks in turbulent molecular clouds
• Constraint on ion-neutral drift velocity in the Class 0 protostar B335 from ALMA observations
• Time-dependent simulations of steady C-type shocks
• Probing the Turbulence Dissipation Range and Magnetic Field Strengths in Molecular Clouds. II. Directly Probing the Ion-neutral Decoupling Scale
• Probing the Turbulent Ambipolar Diffusion Scale in Molecular Clouds with Spectroscopy
• Transient evolution of C-type shocks in dusty regions of varying density

Cited by in corpus (2)

• The Drag Instability in a 2D Isothermal C-shock
• Revealing the drag instability in one-fluid nonideal MHD simulations of a 1D isothermal C-shock