SZ星系团巡天及其宇宙学意义
张宇颖
(中国科学院国家天文台 北京 100012)
摘 要
存在于星系团电离气体中的大量高温电子会对宇宙微波背景的光子产生逆康普顿散射,引起所谓的Sunyaev-Zel'
dovich (SZ)效应。SZ效应是研究星系团的一种非常有效的手段,特别是SZ效应只与星系团的内禀性质有关,而与所处的位置无关,这有利于发现高红移的星系团,因此对星系团的演化有着极其重要的意义。正在建造中的SZ巡天望远镜,将提供一条全新的确定宇宙参数的有效途径,如物质密度参量(ΩM)、真空能密度参量(ΩΛ)和8h-1Mpc尺度内的质量涨落均方差(σ8
)。SZ星系团巡天确定宇宙参数,特别是定量分析利用SZ星系团巡天确定宇宙参数中可能存在的所有不确定因素,可以更好地限制宇宙学模型。在SZ星系团巡天完成之前,人们必须对这些不确定因素有清楚的了解,以便能利用未来的SZ星系团巡天结果有效地测量宇宙参数。
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The
Sunyaev-Zel'dovich Effect Cluster Surveys
and Their Cosmological Significance
Zhang Yuying
(National Astronomical Observatories, Chinese Academy of Sciences, Beijing
100012)
Abstract
Electrons in clusters of galaxies interact the passing photons of the
cosmic microwave background radiation field through the inverse
Compton scattering, which is called the Sunyaev-Zel'dovich (SZ)
Effect. As it is redshift-independent and insensitive to detailed
structure, it provides a powerful probe for studies of distant
clusters of galaxies and their evolution. The under-constructed
no-target SZ effect cluster
surveys will best constrain cosmological primary parameters.
Summarizing the SZ effect and quantitatively analyzing all kinds of
uncertainties in the theoretical
prediction of the SZ cluster counts are very important for precisely
determination of cosmological parameters. It is crucial to evaluate the
uncertainties in current theoretical prediction before applying it into
future SZ surveys.
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