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arXiv 1409.0880astro-ph.CO
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Laniakea超星系团

The Laniakea supercluster of galaxies

R. Brent Tully, Helene Courtois, Yehuda Hoffman, Daniel Pomarède

摘要:

半导体聚集成簇并沿着细丝聚集,并且在称为空隙的大区域中缺失。这些结构可以在光谱测量的地图上看到,这些地图揭示了相互连接的结构网络,没有明确的边界。星系高度密集的扩展区域被称为“超星系团”,尽管这个术语并不精确。然而,还有另一种方法来分析结构。如果直接测量从地球到每个星系的距离,那么可以从观测到的速度中减去平均宇宙膨胀,即距离乘以哈勃常数的乘积,从而得出奇特的速度。奇特速度是从宇宙膨胀的视线偏离,由引力摄动产生;奇特速度的地图可以转化为物质分布的地图。在这里,我们报告了一个结构图,使用一个目录的特殊速度。我们找到了特殊速度流分叉的位置,就像水在分水岭上分叉一样,我们追踪了我们周围分叉点的表面。在这个表面所包围的体积内,星系的运动在除去平均宇宙膨胀和长程流之后是向内的。我们将超星系团定义为这样一个表面内的体积,因此我们定义了我们的家庭超星系团的范围,我们称之为Laniakea。本文的一个关键组成部分是一个附带的电影,可以在http://irfu.cea.fr/laniakea或http://vimeo.com/pomarede/laniakea上观看(也是3D)和下载

英文摘要:

Galaxies congregate in clusters and along filaments, and are missing from large regions referred to as voids. These structures are seen in maps derived from spectroscopic surveys that reveal networks of structure that are interconnected with no clear boundaries. Extended regions with a high concentration of galaxies are called 'superclusters', although this term is not precise. There is, however, another way to analyse the structure. If the distance to each galaxy from Earth is directly measured, then the peculiar velocity can be derived from the subtraction of the mean cosmic expansion, the product of distance times the Hubble constant, from observed velocity. The peculiar velocity is the line-of-sight departure from the cosmic expansion and arises from gravitational perturbations; a map of peculiar velocities can be translated into a map of the distribution of matter. Here we report a map of structure made using a catalogue of peculiar velocities. We find locations where peculiar velocity flows diverge, as water does at watershed divides, and we trace the surface of divergent points that surrounds us. Within the volume enclosed by this surface, the motions of galaxies are inward after removal of the mean cosmic expansion and long range flows. We define a supercluster to be the volume within such a surface, and so we are defining the extent of our home supercluster, which we call Laniakea. A key component of this paper is an accompanying movie that can be viewed (also in 3D) and downloaded at http://irfu.cea.fr/laniakea or http://vimeo.com/pomarede/laniakea

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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