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arXiv 1809.09560astro-ph.CO
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利用星系团的普朗克和XMM-牛顿观测推导哈勃常数

Deriving the Hubble constant using Planck and XMM-Newton observations of galaxy clusters

Arpine Kozmanyan, Hervé Bourdin, Pasquale Mazzotta, Elena Rasia, Mauro Sereno

摘要:

通过Sunyaev Zeldovich(SZ)效应在X射线和微波波长下观测星系团,确定哈勃常数的值的可能性早已为人所知。以前的测量一直受到观测数据中相对较大的误差和严重偏差的困扰,例如,由集群三轴性和块状。\textit{Planck}的出现使我们能够映射康普顿参数y,即SZ效应的幅度,在中间星团中心半径处具有前所未有的精度,这反过来又允许与X射线测量进行详细的空间分辨比较。鉴于这种更高质量的观测数据,我们开发了一种贝叶斯方法,该方法结合了从大规模集群的流体动力学模拟中获得的集群内介质物理学的先验知识,具有测量不确定性。我们将我们的方法应用到61个红移z < 0.5的星系团的样本中,用普朗克和XMM-牛顿观测,发现H_0=67 \pm 3 km s^{-1} Mpc^{-1}。

英文摘要:

The possibility of determining the value of the Hubble constant using observations of galaxy clusters in X-ray and microwave wavelengths through the Sunyaev Zeldovich (SZ) effect has long been known. Previous measurements have been plagued by relatively large errors in the observational data and severe biases induced, for example, by cluster triaxiality and clumpiness. The advent of \textit{Planck} allows us to map the Compton parameter y, that is, the amplitude of the SZ effect, with unprecedented accuracy at intermediate cluster-centric radii, which in turn allows performing a detailed spatially resolved comparison with X-ray measurements. Given such higher quality observational data, we developed a Bayesian approach that combines informed priors on the physics of the intracluster medium obtained from hydrodynamical simulations of massive clusters with measurement uncertainties. We apply our method to a sample of 61 galaxy clusters with redshifts up to z < 0.5 observed with Planck and XMM-Newton observations and find H_0=67 \pm 3 km s^{-1} Mpc^{-1}.

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