The Sunyaev-Zel'dovich angular power spectrum as a probe of cosmological parameters
The Sunyaev-Zel'dovich angular power spectrum as a probe of cosmological parameters
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DOI：
10.1046/j.1365-8711.2002.05889.x
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发表时间：
2002-05
影响因子：
4.8
通讯作者：
E. Komatsu;U. Seljak
中科院分区：
文献类型：
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作者：
E. Komatsu;U. Seljak
Sunyaev-Zel'dovich（SZ）效应的角功率谱是宇宙学的一个强有力的探测器。它比现场的单个集群更容易检测，对观测选择效应不敏感，并且不需要在集群质量和流量之间进行校准，减少了主导集群计数约束的系统误差。它收到的主要贡献维里化集群区域维里半径的20%和40%之间，因此是相对不敏感的知之甚少的气体物理在集群中心，如冷却或（预）加热。在本文中，我们推导出一个精细的解析预测SZ角功率谱使用的通用气体密度和温度分布和暗物质晕质量函数。预测的功率谱没有自由参数，并且对于2000 < l < 10 000，拟合所有已发表的流体动力学模拟结果以优于2的因子。我们发现角功率谱Cl的标度为Cl <$σ78（Ωbh）2，并且几乎不依赖于其它所有的宇宙学参数。这与局部星系团丰度研究不同，后者给出了σ8和Ωm之间的关系。我们还计算了协方差矩阵的Cl使用晕模型，并找到一个很好的协议相对于模拟。我们认为，SZ功率谱的最佳约束来自l的大质量星团主导，对于这些星团来说，冷却、加热和星星形成的细节并不是很重要。我们估计了用抽样方差有限的观测值确定σ8（Ωbh）2/7的能力，发现对于一个具有arcmin分辨率的几平方度的测量，应该能够确定σ8到百分之几以内，其余的不确定性由理论模型决定。如果最近由宇宙背景成像仪（CBI）和伯克利伊利诺斯州马里兰州协会（比马）的实验报告的小尺度上宇宙微波背景功率的过度是由于SZ效应，那么我们发现σ8（Ωbh/0.035）0.29= 1.04 ± 0.12在95%的置信水平（统计）和剩余的10%的系统（理论）不确定性。
The angular power spectrum of the Sunyaev–Zel'dovich (SZ) effect is a powerful probe of cosmology. It is easier to detect than individual clusters in the field, is insensitive to observational selection effects and does not require a calibration between cluster mass and flux, reducing the systematic errors that dominate the cluster-counting constraints. It receives a dominant contribution from virialized cluster region between 20 and 40 per cent of the virial radius and is thus relatively insensitive to the poorly known gas physics in the cluster centre, such as cooling or (pre)heating. In this paper we derive a refined analytic prediction for the SZ angular power spectrum using the universal gas density and temperature profile and the dark matter halo mass function. The predicted power spectrum has no free parameters and fits all of the published hydrodynamic simulation results to better than a factor of 2 for 2000 < l < 10 000. We find that the angular power spectrum Cl scales as Cl∝σ78(Ωbh)2 and is almost independent of all of the other cosmological parameters. This differs from the local cluster abundance studies, which give a relation between σ8 and Ωm. We also compute the covariance matrix of Cl using the halo model and find a good agreement relative to the simulations. We argue that the best constraint from the SZ power spectrum comes from l∼ 3000, where the sampling variance is sufficiently small and the spectrum is dominated by massive clusters above 1014h−1 M⊙ for which cooling, heating and details of star formation are not very important. We estimate how well we can determine σ8(Ωbh)2/7 with sampling-variance-limited observations and find that for a several-square-degree survey with arcmin resolution one should be able to determine σ8 to within a few per cent, with the remaining uncertainty dominated by theoretical modelling. If the recent excess of the cosmic microwave background power on small scales reported by Cosmic Background Imager (CBI) and Berkeley Illinois Maryland Association (BIMA) experiments is due to the SZ effect, then we find σ8(Ωbh/0.035)0.29= 1.04 ± 0.12 at 95 per cent confidence level (statistical) and with a residual 10 per cent systematic (theoretical) uncertainty.