A Measurement of Large-Scale Peculiar Velocities of Clusters of Galaxies: Results and Cosmological Implications
A Measurement of Large-Scale Peculiar Velocities of Clusters of Galaxies: Results and Cosmological Implications
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DOI：
10.1086/592947
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发表时间：
2008-09
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影响因子：
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通讯作者：
A. Kashlinsky;F. Atrio-Barandela;D. Kocevski;H. Ebeling
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文献类型：
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作者：
A. Kashlinsky;F. Atrio-Barandela;D. Kocevski;H. Ebeling
通过研究星系团内部的热X射线气体散射微波光子而产生的宇宙微波背景(CMB)的涨落，可以测量星系团的特殊速度。虽然对于单个星团，这样的测量会导致很大的误差，但大的星团统计样本允许人们研究由样本的整体整体流动主导的累积量，并向下积分统计误差。我们使用迄今为止最大的全天X射线星系团星表和3年的WMAP CMB数据给出了这样的测量结果。我们发现在至少≳300h−1Mpc的尺度上有一个强烈而连贯的块状流，这是我们目录的极限。这种流动很难用协调的Λ清洁发展机制模型框架内的引力演化来解释，而且可能表明遥远的通货膨胀前的不均质性在整个当前地平线上造成的倾斜。
Peculiar velocities of clusters of galaxies can be measured by studying the fluctuations in the cosmic microwave background (CMB) generated by the scattering of the microwave photons by the hot X-ray-emitting gas inside clusters. While for individual clusters such measurements result in large errors, a large statistical sample of clusters allows one to study cumulative quantities dominated by the overall bulk flow of the sample with the statistical errors integrating down. We present results from such a measurement using the largest all-sky X-ray cluster catalog combined to date and the 3 yr WMAP CMB data. We find a strong and coherent bulk flow on scales out to at least ≳300 h−1 Mpc, the limit of our catalog. This flow is difficult to explain by gravitational evolution within the framework of the concordance ΛCDM model and may be indicative of the tilt exerted across the entire current horizon by far-away pre-inflationary inhomogeneities.