Cosmic-Ray-modified and driven instabilities

TL;DR

This paper reviews how cosmic rays influence macro- and micro-instabilities in the interstellar medium, focusing on linear growth rates and magnetic field saturation, with an emphasis on streaming instability driven by anisotropic cosmic-ray distributions.

Contribution

It provides a comprehensive derivation of linear growth rates of cosmic-ray-induced instabilities and discusses numerical simulations of magnetic field saturation, highlighting the streaming instability.

Findings

Derivation of linear growth rates for cosmic-ray-driven instabilities

Insights into magnetic field saturation mechanisms

Analysis of streaming instability driven by anisotropic cosmic-ray distributions

Abstract

These lectures address the effects of Cosmic Rays over macro-instabilities which develop in the interstellar medium and the micro-instabilities the particles are able to trigger themselves. The lectures are centered on the derivation of linear growth rates but also discuss some numerical simulations addressing the issue of magnetic field saturation. A particular emphasis is made on the streaming instability, an instability driven by anisotropic cosmic-ray distributions.