Constraints on O m and s 8 from the potential-based cluster temperature function
Constraints on O m and s 8 from the potential-based cluster temperature function
复制标题
基于势的团簇温度函数对 O m 和 s 8 的约束
DOI：
10.1093/mnras/stv2043
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发表时间：
2015
影响因子：
4.8
通讯作者：
Angrick C
中科院分区：
文献类型：
--
作者：
Angrick C
星系团的丰度原则上是一个强有力的工具来约束宇宙学参数，特别是Ω和σ8，由于指数依赖于高质量的制度。虽然最好的观测数据是X射线温度和光度，但星系团的丰度通常被预测为质量的函数。因此，内在的散射和质量与温度或光度之间的标度关系的不确定性降低了星系团约束宇宙学参数的可靠性。在这篇文章中，我们进一步完善了星系团的X射线温度函数，该模型基于宇宙引力势扰动的统计数据，并建议通过包括一个改进的分析合并模型来取代经典的基于质量的温度函数，并将理论预测与宇宙学流体动力学模拟的结果进行比较。虽然我们已经找到了一个很好的协议，如果我们比较基于质量加权温度的集群温度函数，包括红移依赖的标度之间的质量和光谱温度产生更好的协议之间的理论模型和数值结果。作为概念的证明，将这种额外的标度纳入我们的模型中，我们从星系团的X射线样本中约束宇宙学参数Ω和σ 8，并在1σ水平上尝试性地发现与最近的普朗克任务的宇宙微波背景的结果相一致。
The abundance of galaxy clusters is in principle a powerful tool to constrain cosmological parameters, especially Ωmand σ8, due to the exponential dependence in the high-mass regime. While the best observables are the X-ray temperature and luminosity, the abundance of galaxy clusters, however, is conventionally predicted as a function of mass. Hence, the intrinsic scatter and the uncertainties in the scaling relations between mass and either temperature or luminosity lower the reliability of galaxy clusters to constrain cosmological parameters. In this article, we further refine the X-ray temperature function for galaxy clusters by Angrick et al., which is based on the statistics of perturbations in the cosmic gravitational potential and proposed to replace the classical mass-based temperature function, by including a refined analytic merger model and compare the theoretical prediction to results from a cosmological hydrodynamical simulation. Although we find already a good agreement if we compare with a cluster temperature function based on the mass-weighted temperature, including a redshift-dependent scaling between mass-based and spectroscopic temperature yields even better agreement between theoretical model and numerical results. As a proof of concept, incorporating this additional scaling in our model, we constrain the cosmological parameters Ωmand σ8from an X-ray sample of galaxy clusters and tentatively find agreement with the recent cosmic microwave background based results from thePlanckmission at 1σ-level.