Spectroscopy of Seyfert Nuclei and Quasar Absorption Lines

在类星体光谱中观测到的吸收谱线已被用于研究星际气体和星系在直接可观测到的距离之外的群集，从而得出关于星系演化和宇宙大尺度结构在宇宙时间内演化的重要结论。为了研究原始气体云的组成和星系组成的早期演化，这些观测将被扩展。在附近的501个星系中心，将完成一项搜索，寻找类似类星体的微弱活动证据。最终目的是阐明在遥远的过去，大多数星系是否都是发光的类星体，以及它们是否包含不活跃的黑洞，而这些黑洞现在正以坠落的恒星或星际气体的形式缺乏燃料。

The absorption lines observed in the spectra of quasars have been used to study the interstellar gas and the clustering of galaxies at distances beyond where they are observable directly, thus leading to important conclusions about the evolution of galaxies and the evolution of the large-scale structure of the Universe in cosmic time. These observations are to be extended in order to study the composition of primordial gas clouds and the early evolution of the compositions of galaxies. A search is to be completed for evidence of weak quasar-like activity in the centers of 501 nearby galaxies. The ultimate aim is to cast light on whether the majority of galaxies were luminous quasars in the remote past and if they contain inactive black holes which are now starved of fuel in the form of infalling stars or interstellar gas.