Galactic Magnetism: Extended is the new Compact

磁场是星际介质(ISM)的四个主要组成部分之一，也就是“恒星之间的物质”。其他成分是气体、尘埃和宇宙射线(高能带电粒子)。磁场被认为对星系压力平衡、恒星形成，甚至对星系本身的形成都很重要。了解我们银河系(和其他星系)内磁场的结构为我们提供了重要的约束，使我们能够建立模型，说明银河系磁场最初是如何形成的，以及它是如何演变的。

Magnetic fields are one of the four primary components of the interstellar medium (ISM), or, 'the stuff between the stars'. The other components are gas, dust, and cosmic rays (highly energetic charged particles). Magnetic fields are believed to be important in galactic pressure balance, star formation, and perhaps even in the formation of galaxies themselves. Understanding the structure of magnetic fields within our Galaxy (and others) provides us with important constraints on models addressing how the Galactic magnetic field originally formed and how it is evolving.