Acoustic instability in the neutral precursor region of collisionless shocks propagating into partially ionized plasmas

Abstract

Recent studies about collisionless shocks in partially ionized plasmas showed that some of neutral particles leak into the shock upstream region from the downstream region. In this paper, we perform a linear analysis and show that acoustic waves are unstable in the neutral precursor region. The acoustic instability amplifies fluctuations of magnetic field and density in the upstream region. The fluctuations are indispensable for the diffusive shock acceleration and could be important for the downstream turbulence.

5 pages, 4 figures, accepted for publication in MNRAS

References in corpus (5)

• Balmer-Dominated Shocks Revisited
• Turbulent magnetic field amplification driven by cosmic-ray pressure gradients
• Turbulent Shear Acceleration
• Non-Maxwellian Proton Velocity Distributions in Nonradiative Shocks
• Simulations of Collisionless Perpendicular Shocks in Partially Ionized Plasmas

Cited by in corpus (8)

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• Magnetic field amplification by collisionless shocks in partially ionized plasmas
• Injection to rapid diffusive shock acceleration at perpendicular shocks in partially ionized plasmas
• Weibel-Mediated Shocks Propagating into Inhomogeneous Electron-Positron Plasmas
• Weibel instability driven by spatially anisotropic density structures
• Polarized Balmer Line Emission from Supernova Remnant Shock Waves Efficiently Accelerating Cosmic Rays
• Magnetic field generation by charge exchange in a supernova remnant in the early universe
• Escape of cosmic rays from perpendicular shocks in the interstellar magnetic field