标题： 多相星系际介质及其与星系的关系：观测视角 显示英文标题

标题： The multiphase circumgalactic medium and its relation to galaxies: an observational perspective

摘要： 星系际介质（CGM）是星系中的一个关键组成部分，因为它调节着星系活动所必需的重子循环。 由于温度、密度、金属丰度和电离状态的复杂分布，CGM也是一个多相介质，因此它本身也非常复杂。 因此，了解CGM需要结合多种观测技术。 本文首先回顾了吸收光谱学与电离条件建模相结合如何提供有关CGM基本物理属性的关键见解。 接下来，研究了快速发展的成像和积分场光谱学在使用氢和金属线作为示踪剂研究晕气方面的应用。 最后，通过考虑目前直接将星系与其晕气联系起来的研究，强调了CGM在星系演化中的重要作用。 还探讨了环境如何以新的维度影响CGM并改变星系的演化。 显示英文摘要

摘要： The circumgalactic medium (CGM) is a vital element in galaxies, as it mediates the baryon cycle essential for regulating galaxy activity. It is also highly complex due to the intricate distributions of temperature, density, metallicity, and ionization that make the CGM a multiphase medium. Therefore, learning about the CGM requires combining various observational techniques. This contribution starts by reviewing how absorption spectroscopy, together with modeling of the ionization conditions, yields critical insights into the underlying physical properties of the CGM. Next, the rapidly growing application of imaging and integral field spectroscopy for studying the halo gas in emission, using hydrogen and metal lines as tracers, is examined. Finally, the essential role of the CGM in galaxy evolution is highlighted by considering current studies that directly link galaxies to their halo gas. The novel dimension of how the environment affects the CGM and alters the evolution of galaxies is also investigated.