The distance duality relation and the temperature profile of galaxy clusters
The distance duality relation and the temperature profile of galaxy clusters
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DOI：
10.1007/s11433-011-4559-7
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发表时间：
2011-02
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影响因子：
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通讯作者：
Shuo Cao;Zong-hong Zhu
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文献类型：
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作者：
Shuo Cao;Zong-hong Zhu
距离对偶关系η =DL（z）（1 +z）−2/DA（z）= 1的有效性，是Etherington互易定理所要求的一个精确结果，其中DA（z）和DL（z）是角距离和光度距离，在宇宙学观测和模型约束中起着重要的作用。在本文中，我们通过假设η是常数或红移的函数来研究这种关系的一些结果。为了约束有关η的参数，我们考虑了Chandra观测到的52个X射线发光星系团的两组气体质量分数数据，它们的红移范围为0.3 - 1.273，温度范围Tgas> 4keV，并假设了两种不同的温度分布。我们发现，对于η的两种参数化，恒定温度分布相对较好地符合距离对偶关系，而具有温度梯度的温度分布（Vikhlinin等人的温度分布）似乎即使在99%CL下也不相容。
The validity of distance duality relation, η =DL(z)(1 +z)−2/DA(z) = 1, an exact result required by the Etherington reciprocity theorem, whereDA(z) andDL(z) are the angular and luminosity distances, plays an essential part in cosmological observations and model constraints. In this paper, we investigate some consequences of such a relation by assuming η a constant or a function of the redshift. In order to constrain the parameters concerning η, we consider two groups of cluster gas mass fraction data including 52 X-ray luminous galaxy clusters observed by Chandra in the redshift range from 0.3 to 1.273 and temperature rangeTgas> 4 keV, under the assumptions of two different temperature profiles. We find that the constant temperature profile is in relatively good agreement with no violation of the distance duality relation for both parameterizations of η, while the one with temperature gradient (the Vikhlinin et al. temperature profile) seems to be incompatible even at 99% CL.