On the nature of highly ionized gas in the circumgalactic environment of galaxies

深入了解星系外区高电离气体的分布和物理性质，对于表征星系内星际气体与星系际介质之间的物质交换具有至关重要的意义。在这个项目中，我们将使用来自所谓的压倒性大型模拟（owl）项目的高分辨率平滑粒子流体动力学（SPH）宇宙学模拟来研究低红移星系环星系环境中高电离气体的性质。我们将沿着穿越星系大尺度环境的视线生成OVI、neviii等高离子的合成吸收光谱，并研究其吸收特征、填充因素和环星系气体组分的物理条件。然后将合成光谱的统计特性与来自FUSE和HST的低红移OVI吸收器的类星体吸收线数据进行比较。我们的项目旨在更好地理解星系高度电离气体包层的物理性质，以及它们与多相、多尺度星际介质和宇宙网的联系。

A thorough understanding of the distribution and physical nature of highly-ionized gas in the outer regions of galaxies is of crucial importance to characterize the matter exchange between the interstellar gas in galaxies and the intergalactic medium. In this project, we will use high-resolution smoothed particle hydrodynamic (SPH) cosmological simulations from the so-called OverWhelmingly Large Simulations (OWLS) project to study the properties of highly-ionized gas in the circumgalactic environment of low-redshift galaxies. We will generate synthetic absorption spectra of high ions such as OVI, Ne VIII, and others along sightlines passing through the large-scale environment of galaxies and study the absorption characteristics, filling factors, and physical conditions in the circumgalactic gas component. The statistical properties of the synthetic spectra then will be compared to quasar absorption-line data of low-redshift OVI absorbers from FUSE and HST. Our project is aiming at a better understanding of the physical nature of the highly-ionized gaseous envelopes of galaxies and their connection to the multi-phase, multi-scale interstellar medium and the cosmic web.