期刊
ASTROPHYSICAL JOURNAL
卷 618, 期 1, 页码 L1-L4出版社
UNIV CHICAGO PRESS
DOI: 10.1086/427554
关键词
cosmological parameters; cosmology : theory; dark matter; galaxies : clusters : general; X-rays : galaxies
The thermal properties of hydrodynamical simulations of galaxy clusters are usually compared to observations by relying on the emission-weighted temperature T-ew instead of on the spectroscopic X-ray temperature T-spec, which is obtained by actual observational data. In a recent paper, Mazzotta et al. show that if the intracluster medium is thermally complex, T-ew fails at reproducing T-spec. They propose a new formula, the spectroscopic-like temperature, T-sl, which approximates T-spec better than a few percent. By analyzing a set of hydrodynamical simulations of galaxy clusters, we find that T-sl is lower than T-ew by 20%-30%. as a consequence, the normalization of the M-T-sl relation from the simulations is larger than the observed one by about 50%. If masses in simulated clusters are estimated by following the same assumptions of hydrostatic equilibrium and beta-model gas density profile, as is often done for observed clusters, then the M-T relation decreases by about 40% and significantly amplitude of the power spectrum from the X-ray temperature function could bias low sigma(s) by 10%-20%. This may alleviate the tension between the value of sigma(s) inferred from the cluster number density and those from the cosmic microwave background and large-scale structure.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据