Partially Ionized Plasmas in Astrophysics

TL;DR

This review discusses the physics of partially ionized plasmas in various astrophysical environments, highlighting recent advances, unresolved questions, and future research directions.

Contribution

It provides a comprehensive overview of the physical effects and recent developments in the study of partially ionized plasmas in astrophysics.

Findings

Identification of key physical effects unique to partially ionized plasmas

Summary of recent observational and theoretical advances

Discussion of open questions and future research directions

Abstract

Partially ionized plasmas are found across the Universe in many different astrophysical environments. They constitute an essential ingredient of the solar atmosphere, molecular clouds, planetary ionospheres and protoplanetary disks, among other environments, and display a richness of physical effects which are not present in fully ionized plasmas. This review provides an overview of the physics of partially ionized plasmas, including recent advances in different astrophysical areas in which partial ionization plays a fundamental role. We outline outstanding observational and theoretical questions and discuss possible directions for future progress.