The influence of large-scale structures on halo shapes and alignments
The influence of large-scale structures on halo shapes and alignments
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DOI：
10.1111/j.1365-2966.2006.10555.x
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发表时间：
2006-05
影响因子：
4.8
通讯作者：
G. Altay;J. Colberg;R. Croft
中科院分区：
文献类型：
--
作者：
G. Altay;J. Colberg;R. Croft
星系团的排列（宾格里效应）以及星系本身的排列长期以来一直在观测和理论上进行研究。在这里，我们测试的影响，大规模的结构和潮汐场的形状和排列的集群大小和星系大小的暗物质晕。我们使用一个高分辨率的N-体模拟的冷暗物质（ACDM）宇宙，连同科尔伯格，克鲁格霍夫和康诺利，谁确定了细丝连接对集群的结果。我们发现，集群对连接的灯丝是强烈的集群集群轴对齐，而不连接的。对于较小的星系大小的晕，也有一个对齐信号，但其强度与晕是否是明显的大尺度结构的一部分无关。此外，我们发现没有可测量的依赖星系晕形状的成员资格的灯丝。我们还量化了潮汐场的影响，并发现这些确实与晕的排列密切相关。因此，大多数晕的排列是由潮汐场引起的，而星团大小的晕则是通过物质从细丝中流入的额外机制而强烈排列的。
Alignments of galaxy clusters (the Binggeli effect), as well as of galaxies themselves have long been studied both observationally and theoretically. Here, we test the influence of large-scale structures and tidal fields on the shapes and alignments of cluster-size and galaxy-size dark matter haloes. We use a high-resolution N-body simulation of a A cold dark matter (ACDM) universe, together with the results of Colberg, Krughoff & Connolly, who identified filaments connecting pairs of clusters. We find that cluster pairs connected by a filament are strongly aligned with the cluster-cluster axis, whereas unconnected ones are not. For smaller, galaxy-size haloes, there also is an alignment signal, but its strength is independent of whether the halo is part of an obvious large-scale structure. Additionally, we find no measurable dependence of galaxy halo shape on membership of a filament. We also quantify the influence of tidal fields and find that these do correlate strongly with alignments of haloes. The alignments of most haloes are thus caused by tidal fields, with cluster-size haloes being strongly aligned through the added mechanism of infall of matter from filaments.