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arXiv 1911.03097astro-ph.CO
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用$Planck$ tSZ功率谱修正的星系团压力剖面的宇宙学意义

Cosmological implications of a modified galaxy cluster pressure profile using the $Planck$ tSZ power spectrum

F. Ruppin, F. Mayet, J. F. Macías-Pérez, L. Perotto

摘要:

星系团的平均压力分布是基于通过Sunyaev-Zel'dovich(SZ)效应观测到的星系团的宇宙学分析中的一个关键要素。这一配置文件的形状和幅度的变化可以解释目前观察到的宇宙学约束之间的差异的一部分,从分析的CMB主要各向异性和那些从集群丰度在SZ调查的固定质量偏置参数。通过对$Planck$测量的SZ功率谱的分析,我们研究了平均压力剖面修正的宇宙学意义。我们定义了两个平均压力分布两侧的$Planck$的观测附近的集群。这些配置文件的参数的选择,以确保其兼容性的压力和气体质量分数的分布在低红移观察到的配置文件。我们发现显着的差异,通过使用这两个配置文件,以适应$Planck$ SZ功率谱和以前的分析中发现的宇宙学参数。我们得出结论,平均归一化压力曲线的幅度的${\sim}15\%$减小足以减轻从CMB和聚类分析中观察到的$σ_8$和$Ω_m$的约束之间的差异。

英文摘要:

The mean pressure profile of the cluster population is a key element in cosmological analyses based on surveys of galaxy clusters observed through the Sunyaev-Zel'dovich (SZ) effect. A variation of both the shape and the amplitude of this profile could explain part of the discrepancy currently observed between the cosmological constraints obtained from the analyses of the CMB primary anisotropies and those from cluster abundance in SZ surveys for a fixed mass bias parameter. We study the cosmological implications of a modification of the mean pressure profile through the analysis of the SZ power spectrum measured by $Planck$. We define two mean pressure profiles on either side of the one obtained from the observation of nearby clusters by $Planck$. The parameters of these profiles are chosen to ensure their compatibility with the distributions of pressure and gas mass fraction profiles observed at low redshift. We find significant differences between the cosmological parameters obtained by using these two profiles to fit the $Planck$ SZ power spectrum and those found in previous analyses. We conclude that a ${\sim}15\%$ decrease of the amplitude of the mean normalized pressure profile is sufficient to alleviate the discrepancy observed between the constraints of $σ_8$ and $Ω_m$ from the CMB and cluster analyses.

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