论文标题
宇宙空隙中的HST /COS Lyman-Alpha吸收器
HST /COS Lyman-alpha Absorbers in Cosmic Voids
论文作者
论文摘要
我们研究了宇宙空隙中Lyman-$α$（LY $α$）的空间分布。我们在Sloan数字天空调查数据版本7（SDSS DR7）中创建了一个宇宙空隙目录，并使用Void Analysis Software Toolkit（vast）的无效芬德算法（SDSS DR7）。迄今为止，使用最大的低红移（Z $ \ leq $ 0.75）Igm吸收器目录，我们确定了392 ly $α$吸收器内部的吸收室。在空隙内（65％）的LY $α$吸收器的比例与空隙的体积填充分数（68％）相当（68％），并且明显大于空隙内的星系比例（21％）。在空隙内，LY $α$吸收器的空间分布与星系的空间分布明显不同。星系密度在空隙边缘附近急剧上升，而Ly $α$吸收器密度相对均匀。 ly $α$吸收器的径向分布与随机分布有很大的不同。我们发现，比更高的色谱柱密度LY $α$吸收器相比，较低的色谱柱密度LY $α$吸收器在空隙内的集中集中。这些结果表明存在两个LY $α$吸收器的种群：低柱密度系统几乎均匀分布在空隙边缘处与星系相关的空隙和系统的内部。
We investigate the spatial distribution of Lyman-$α$ (Ly $α$) absorbers within cosmic voids. We create a catalogue of cosmic voids in Sloan Digital Sky Survey Data Release 7 (SDSS DR7) with the VoidFinder algorithm of the Void Analysis Software Toolkit (VAST). Using the largest catalogue of low-redshift (z $\leq$ 0.75) IGM absorbers to date, we identify 392 Ly $α$ absorbers inside voids. The fraction of Ly $α$ absorbers inside voids (65 per cent) is comparable to the volume filling fraction of voids (68 per cent), and significantly greater than the fraction of galaxies inside voids (21 per cent). Inside voids, the spatial distribution of Ly $α$ absorbers differs markedly from that of galaxies. Galaxy density rises sharply near void edges, while Ly $α$ absorber density is relatively uniform. The radial distribution of Ly $α$ absorbers inside voids differs marginally from a random distribution. We find that lower column density Ly $α$ absorbers are more centrally concentrated inside voids than higher column density Ly $α$ absorbers. These results suggest the presence of two populations of Ly $α$ absorbers: low column density systems that are nearly uniformly distributed in the interiors of voids and systems associated with galaxies at the edges of voids.
