The ROSAT-ESO Flux-Limited X-Ray (REFLEX) Galaxy Cluster Survey VI: Constraints on the cosmic matter density from the KL power spectrum
The ROSAT-ESO Flux-Limited X-Ray (REFLEX) Galaxy Cluster Survey VI: Constraints on the cosmic matter density from the KL power spectrum
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ROSAT-ESO 通量限制 X 射线 (REFLEX) 星系团巡天 VI：KL 功率谱对宇宙物质密度的约束
DOI：
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发表时间：
2002
期刊：
影响因子：
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通讯作者：
H. Boehringer
中科院分区：
文献类型：
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作者：
P. Schuecker;L. Guzzo;C. Collins;H. Boehringer
利用样本相关矩阵的KL特征向量和特征值分析了反射型星系团的空间涨落。该方法避免了相关功率谱密度对GPC尺度上所有先前的星团测量的干扰影响。综合测试使用从哈勃体积模拟中提取的一大组独立的类似反射的模拟簇样本。研究发现，利用反射数据在GPC标尺上进行无偏测量是可能的。在93.4%的置信度水平上，KL本征值的分布与高斯随机场一致。假定冷暗物质模型是空间平坦的，对不同样本体积、基准宇宙学、质量-X射线光度关系和重子密度的似然等值线的边际化，给出了0.03lt；Ωmh2；0.19物质密度的95.4%的可信区间。N体模拟表明，宇宙变化虽然难以估计，但预计将使可信区间增加约50%。
The Karhunen-Loeve (KL) eigenvectors and eigenvalues of the sample correlation matrix are used to analyse the spatial fluctuations of the REFLEX clusters of galaxies. The method avoids the disturbing effects of correlated power spectral densities that affect all previous cluster measurements on Gpc scales. Comprehensive tests use a large set of independent REFLEX-like mock cluster samples extracted from the Hubble Volume Simulation. It is found that unbiased measurements on Gpc scales are possible with the REFLEX data. The distribution of the KL eigenvalues is consistent with a Gaussian random field on the 93.4 per cent confidence level. Assuming spatially flat cold dark matter models, the marginalization of the likelihood contours over different sample volumes, fiducial cosmologies, mass-X-ray luminosity relations and baryon densities, yields a 95.4 per cent confidence interval for the matter density of 0.03 < Ω m h 2 < 0.19. The N-body simulations show that cosmic variance, although difficult to estimate, is expected to increase the confidence intervals by about 50 per cent.