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.

中文翻译：

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天体物理学中的部分电离等离子体

在许多不同的天体物理环境中，在整个宇宙中都发现了部分电离的等离子体。它们构成了太阳大气、分子云、行星电离层和原行星盘等环境的重要组成部分，并显示出完全电离等离子体所不存在的丰富物理效应。这篇综述概述了部分电离等离子体的物理学，包括在不同天体物理学领域的最新进展，其中部分电离起着重要作用。我们概述了突出的观察和理论问题，并讨论了未来进展的可能方向。