论文标题
欧几里得准备。 xxvii。星系簇的2点相关函数的协方差模型验证
Euclid preparation. XXVII. Covariance model validation for the 2-point correlation function of galaxy clusters
论文作者
论文摘要
目标。我们验证了一个半分析模型，以实现星系簇的真实空间2分相关函数的协方差。方法。使用1000个pinocchio光锥模仿星系簇的预期欧几里得样品，我们校准了一个简单的模型，以准确描述聚类协方差。然后，我们使用这样的模型来量化对协方差变化的可能性分析响应，并研究依赖宇宙学矩阵的影响，这是对星系簇的欧几里得调查的统计水平的影响。结果。我们发现，具有泊松射击的高斯模型无法正确预测星系簇的2分相关函数的协方差。通过引入模拟中拟合的几个其他参数，提出的模型以10％的精度再现了数值协方差，在宇宙学参数的功绩$ω__{\ rm m} $和$σ_8$上的差异约为5％。此外，我们发现协方差的宇宙学依赖性增加了平均值中未包含的有价值的信息，从而显着提高了群集聚类的约束能力。最后，我们发现，可以考虑大量框架来进一步提高宇宙学的功绩。我们的结果对来自星系簇的欧几里得调查的两点聚类统计数据的宇宙学约束具有重要意义。
Aims. We validate a semi-analytical model for the covariance of real-space 2-point correlation function of galaxy clusters. Methods. Using 1000 PINOCCHIO light cones mimicking the expected Euclid sample of galaxy clusters, we calibrate a simple model to accurately describe the clustering covariance. Then, we use such a model to quantify the likelihood analysis response to variations of the covariance, and investigate the impact of a cosmology-dependent matrix at the level of statistics expected for the Euclid survey of galaxy clusters. Results. We find that a Gaussian model with Poissonian shot-noise does not correctly predict the covariance of the 2-point correlation function of galaxy clusters. By introducing few additional parameters fitted from simulations, the proposed model reproduces the numerical covariance with 10 per cent accuracy, with differences of about 5 per cent on the figure of merit of the cosmological parameters $Ω_{\rm m}$ and $σ_8$. Also, we find that the cosmology-dependence of the covariance adds valuable information that is not contained in the mean value, significantly improving the constraining power of cluster clustering. Finally, we find that the cosmological figure of merit can be further improved by taking mass binning into account. Our results have significant implications for the derivation of cosmological constraints from the 2-point clustering statistics of the Euclid survey of galaxy clusters.
