The impact of astrophysical dust grains on the confinement of cosmic rays

Abstract

We argue that charged dust grains could significantly impact the confinement and transport of galactic cosmic rays. For sub-GeV to ~1000GeV cosmic rays, small-scale parallel Alfvén waves, which isotropize cosmic rays through gyro-resonant interactions, are also gyro-resonant with charged grains. If the dust is nearly stationary, as in the bulk of the interstellar medium, Alfvén waves are damped by dust. This will reduce the amplitude of Alfvén waves produced by the cosmic rays through the streaming instability, thus enhancing cosmic-ray transport. In well-ionized regions, the dust damping rate is larger by a factor of ~10 than other mechanisms that damp parallel Alfvén waves at the scales relevant for ~GeV cosmic rays, suggesting that dust could play a key role in regulating cosmic-ray transport. In astrophysical situations in which the dust moves through the gas with super-Alfvénic velocities, Alfvén waves are rendered unstable, which could directly scatter cosmic rays. This interaction has the potential to create a strong feedback mechanism where dust, driven through the gas by radiation pressure, then strongly enhances the confinement of cosmic rays, increasing their capacity to drive outflows. This mechanism may act in the circumgalactic medium around star-forming galaxies and active galactic nuclei.

References in corpus (18)

• The Circumgalactic Medium
• Discrepant hardening observed in cosmic-ray elemental spectra
• Cosmic Ray Propagation: Nonlinear Diffusion Parallel and Perpendicular to Mean Magnetic Field
• Cosmic-ray propagation with DRAGON2: I. numerical solver and astrophysical ingredients
• The origin of galactic cosmic rays
• Streaming Instability for Particle-Size Distributions
• Damping of Alfven waves by Turbulence and its Consequences: from Cosmic-Rays Streaming to Launching Winds
• Cosmic ray production in supernovae
• Effects of Different Cosmic Ray Transport Models on Galaxy Formation
• Simulating Gamma-ray Emission in Star-forming Galaxies
• Cosmic Ray Transport, Energy Loss, and Influence in the Multiphase Interstellar Medium
• Magnetohydrodynamic-Particle-in-Cell Simulations of the Cosmic-Ray Streaming Instability: Linear Growth and Quasi-linear Evolution
• dHybridR: a Hybrid--Particle-in-Cell Code Including Relativistic Ion Dynamics
• High $\beta$ Effects on Cosmic Ray Streaming in Galaxy Clusters
• On the spectrum of stable secondary nuclei in cosmic rays
• The turbulent life of dust grains in the supernova-driven, multi-phase interstellar medium
• Radiation-pressure-driven dust transport to galaxy halos at $z\sim 10$
• Thermal damping of Weak Magnetosonic Turbulence in the Interstellar Medium

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• The Physics of Galactic Winds Driven by Cosmic Rays II: Isothermal Streaming Solutions
• Grammage of cosmic rays in the proximity of supernova remnants embedded in a partially ionized medium
• Influence of Ion-Neutral Damping on the Cosmic-Ray Streaming Instability: Magnetohydrodynamic Particle-in-cell Simulations
• Towards First-principle Characterization of Cosmic-ray Transport Coefficients from Multi-scale Kinetic Simulations
• Why are thermally- and cosmic ray-driven galactic winds fundamentally different?
• Supernova Dust Evolution Probed by Deep-sea 60Fe Time History
• The Cosmic Ray Staircase: the Outcome of the Cosmic Ray Acoustic Instability
• Stress-Testing Cosmic Ray Physics: The Impact of Cosmic Rays on the Surviving Disk of Ram Pressure Stripped Galaxies
• Cosmic-ray current-driven instabilities -- revisiting environmental conditions
• The Acoustic Resonant Drag Instability with a Spectrum of Grain Sizes
• Numerical Study of Cosmic Ray Confinement through Dust Resonant Drag Instabilities
• A Simple Sub-Grid Model For Cosmic Ray Effects on Galactic Scales
• Cosmic-ray transport in inhomogeneous media
• AGN cool feedback and analogy with X-ray binaries: from radiation pressure to cosmic ray driven outflows
• A new buoyancy instability in galaxy clusters due to streaming cosmic rays
• Effect of cosmic rays and ionizing radiation on observational ultraviolet plasma diagnostics in the circumgalactic medium
• Velocity decorrelation functions of high-energy cosmic rays propagating in magnetic fields