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arXiv 0802.4462astro-ph
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XMM集群调查:预测宇宙学和集群标度关系参数约束

The XMM Cluster Survey: Forecasting cosmological and cluster scaling-relation parameter constraints

Martin Sahlén, Pedro T. P. Viana, Andrew R. Liddle, A. Kathy Romer, Michael Davidson, Mark Hosmer, Ed Lloyd-Davies, Kivanc Sabirli, Chris A. Collins, Peter E. F… 展开作者

Martin Sahlén, Pedro T. P. Viana, Andrew R. Liddle, A. Kathy Romer, Michael Davidson, Mark Hosmer, Ed Lloyd-Davies, Kivanc Sabirli, Chris A. Collins, Peter E. Freeman, Matt Hilton, Ben Hoyle, Scott T. Kay, Robert G. Mann, Nicola Mehrtens, Christopher J. Miller, Robert C. Nichol, S. Adam Stanford, Michael J. West

摘要:

我们预测的限制值的sigma_8,Omega_m,和集群标度关系参数,我们希望得到的XMM集群调查(XCS)。我们假设一个平坦的Lambda-CDM宇宙,并考虑到一个详细的模拟选择函数的星系团的数量密度的演变进行蒙特卡罗马尔可夫链分析。比较我们目前观察到的集群数量与预测吻合得很好。我们确定预期的退化的约束作为自校准的亮度-温度关系(与散射),包括温度测量误差,并依赖于测光方法估计的星系团红移的结果。我们研究了尺度关系和测量误差假设中的系统误差的影响。仅使用(T,z)自校准,我们期望测量Omega_m到+-0.03(和Omega_Lambda到相同的精度,假设平坦度),以及sigma_8到+-0.05,在该过程中还将亮度-温度关系的归一化和斜率分别限制为+-6%和+-13%(在1 sigma处)。自定标不能联合约束的散射和红移演化的光度-温度关系显着。更多的存档和/或随访数据将改善这一点。我们不希望测量误差或不完善的知识,他们的分布,以降低约束显着。标度关系系统学很容易导致宇宙学约束2 σ或更远离基准模型。我们的治疗是第一个确切的治疗,这种程度的细节,并引入了一个新的“平滑ML”的预期约束的估计。

英文摘要:

We forecast the constraints on the values of sigma_8, Omega_m, and cluster scaling relation parameters which we expect to obtain from the XMM Cluster Survey (XCS). We assume a flat Lambda-CDM Universe and perform a Monte Carlo Markov Chain analysis of the evolution of the number density of galaxy clusters that takes into account a detailed simulated selection function. Comparing our current observed number of clusters shows good agreement with predictions. We determine the expected degradation of the constraints as a result of self-calibrating the luminosity-temperature relation (with scatter), including temperature measurement errors, and relying on photometric methods for the estimation of galaxy cluster redshifts. We examine the effects of systematic errors in scaling relation and measurement error assumptions. Using only (T,z) self-calibration, we expect to measure Omega_m to +-0.03 (and Omega_Lambda to the same accuracy assuming flatness), and sigma_8 to +-0.05, also constraining the normalization and slope of the luminosity-temperature relation to +-6 and +-13 per cent (at 1sigma) respectively in the process. Self-calibration fails to jointly constrain the scatter and redshift evolution of the luminosity-temperature relation significantly. Additional archival and/or follow-up data will improve on this. We do not expect measurement errors or imperfect knowledge of their distribution to degrade constraints significantly. Scaling-relation systematics can easily lead to cosmological constraints 2sigma or more away from the fiducial model. Our treatment is the first exact treatment to this level of detail, and introduces a new `smoothed ML' estimate of expected constraints.

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