The Topology of Large-Scale Structure in the 1.2 Jy IRAS Redshift Survey
The Topology of Large-Scale Structure in the 1.2 Jy IRAS Redshift Survey
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1.2 Jy IRAS 红移巡天大尺度结构拓扑
DOI：
10.1086/304803
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发表时间：
1997
期刊：
影响因子：
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通讯作者：
D. Weinberg
中科院分区：
文献类型：
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作者：
Zacharias A. M. Protogeros;D. Weinberg
我们在1.2Jy IRAS红移测量的体积限制子集中测量了等密度等高线曲面的拓扑(亏格)，其中平滑尺度λ=4、7和12h-1MPC。在12h~(-1)MPC时，观测到的亏格曲线具有类似于高斯随机场所预言的对称形式。在较短的平滑长度下，观察到的亏格曲线在孤立星团或“肉丸”拓扑的方向上有轻微的移动。我们使用从宇宙N体模拟中提取的模拟星表来调查在这种大小的样本中影响拓扑测量的系统偏差，并确定预期随机误差的完整协方差矩阵。我们将误差相关性纳入我们对理论模型的评估中，得到了对绝对拟合优度的频率评估和对模型相对概率的贝叶斯评估。我们将观测到的1.2Jy调查的拓扑结构与动态演化的、无偏的、具有高斯初始条件的引力不稳定模型的预测进行了比较。初始功率谱为n=-1的模型与实验数据的总体一致性最好，而具有低密度冷暗物质功率谱和n=0功率谱的模型也是一致的。观测到的拓扑与具有n=-2的初始高斯模型不一致，并且与具有非高斯气泡拓扑的Voronoi泡沫模型强烈不一致。
We measure the topology (genus) of isodensity contour surfaces in volume-limited subsets of the 1.2 Jy IRAS redshift survey, for smoothing scales λ = 4, 7, and 12 h-1 Mpc. At 12 h-1 Mpc, the observed genus curve has a symmetric form similar to that predicted for a Gaussian random field. At the shorter smoothing lengths, the observed genus curve shows a modest shift in the direction of an isolated cluster or "meatball" topology. We use mock catalogs drawn from cosmological N-body simulations to investigate the systematic biases that affect topology measurements in samples of this size and to determine the full covariance matrix of the expected random errors. We incorporate the error correlations into our evaluations of theoretical models, obtaining both frequentist assessments of absolute goodness of fit and Bayesian assessments of models' relative likelihoods. We compare the observed topology of the 1.2 Jy survey to the predictions of dynamically evolved, unbiased, gravitational instability models that have Gaussian initial conditions. The model with an n = -1 power-law initial power spectrum achieves the best overall agreement with the data, though models with a low-density cold dark matter power spectrum and an n = 0 power-law spectrum are also consistent. The observed topology is inconsistent with an initially Gaussian model that has n = -2, and it is strongly inconsistent with a Voronoi foam model, which has a non-Gaussian, bubble topology.