Combining cluster observables and stacked weak lensing to probe dark energy: Self-calibration of systematic uncertainties
Combining cluster observables and stacked weak lensing to probe dark energy: Self-calibration of systematic uncertainties
复制标题
结合簇可观测量和堆叠弱透镜来探测暗能量：系统不确定性的自校准
DOI：
10.1103/physrevd.83.023008
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发表时间：
2010
影响因子：
5
通讯作者：
M. Takada
中科院分区：
文献类型：
--
作者：
M. Oguri;M. Takada
我们开发了一种新的方法相结合的集群观测值（数量计数和集群集群相关函数）和堆叠的背景星系形状的弱透镜信号，这两者都是在宽视场光学成像调查。假设集群有安全的红移估计，我们表明，联合实验，使重要的系统误差，包括源红移的不确定性和集群质量可观测的关系，通过采用一个单一的人口的背景源星系的透镜分析的自校准。它使我们能够使用堆叠透镜信号在不同的集群红移的相对强度校准源红移的不确定性，这反过来又导致在每个箱中的平均集群质量的准确测量。此外，我们在傅立叶空间中的堆叠透镜信号的公式化简化了Fisher矩阵计算，以及集群偏心效应的边缘化，这是堆叠透镜中最重要的不确定性。我们表明，即将到来的宽场调查产生严格的约束宇宙学参数，包括暗能量参数，没有任何先验的滋扰参数模型系统的不确定性。具体来说，与单独来自集群观测值的暗能量相比，堆叠的透镜信息将暗能量FoM提高了4倍。原始非高斯参数也可以用f_NL~10的水平来约束。在该方法中，源的平均红移被很好地校准到0.1的红移精度，并且每个仓中的平均团簇质量被校准到5-10%的精度，这证明了来自联合实验的系统不确定性的自校准的成功。（节录）
We develop a new method of combining cluster observables (number counts and cluster-cluster correlation functions) and stacked weak lensing signals of background galaxy shapes, both of which are available in a wide-field optical imaging survey. Assuming that the clusters have secure redshift estimates, we show that the joint experiment enables a self-calibration of important systematic errors including the source redshift uncertainty and the cluster mass-observable relation, by adopting a single population of background source galaxies for the lensing analysis. It allows us to use the relative strengths of stacked lensing signals at different cluster redshifts for calibrating the source redshift uncertainty, which in turn leads to accurate measurements of the mean cluster mass in each bin. In addition, our formulation of stacked lensing signals in Fourier space simplifies the Fisher matrix calculations, as well as the marginalization over the cluster off-centering effect, the most significant uncertainty in stacked lensing. We show that upcoming wide-field surveys yield stringent constraints on cosmological parameters including dark energy parameters, without any priors on nuisance parameters that model systematic uncertainties. Specifically, the stacked lensing information improves the dark energy FoM by a factor of 4, compared to that from the cluster observables alone. The primordial non-Gaussianity parameter can also be constrained with a level of f_NL~10. In this method, the mean source redshift is well calibrated to an accuracy of 0.1 in redshift, and the mean cluster mass in each bin to 5-10% accuracies, which demonstrates the success of the self-calibration of systematic uncertainties from the joint experiment. (Abridged)