The Intracluster Gas Fraction in X-ray Clusters : Constraints on the Clustered Mass Density
The Intracluster Gas Fraction in X-ray Clusters : Constraints on the Clustered Mass Density
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X射线团簇中的团簇内气体分数:对团簇质量密度的约束
DOI：
10.1093/mnras/292.2.289
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发表时间：
1997
影响因子：
4.8
通讯作者：
A. Evrard
中科院分区：
文献类型：
--
作者：
A. Evrard
根据大卫、琼斯和福尔曼以及白色和费边最近的观测资料，导出了X射线星团在其流体静力区内的平均团内气体分数。在包含平均密度500倍临界值的半径处，单个样品双权重平均值存在中度（2.4er）差异;使用通过数值模拟校准的维里关系修正结合质量可消除差异，并产生合并的样品平均值和标准误差！气体（rsoo）=（0.060 ± 0.003）h-312。对于具有极端物理假设以最大化团簇气体含量的等级聚类模型，该值限制了总的团簇质量与重子质量的普适比率~/~：;23.1 h3/Z。将其与原始核合成的~的最大值相结合，得到~ h 1/Z < 0.76。一个物理上更合理的方法是基于类星体吸收光谱的低氘丰度推断，并考虑到星系团中的重子，得出的估计值为~ hZ/ 3 = 0.30 ± 0.07，推导过程中涉及的系统误差来源提供了大约30%的额外不确定性。其他的影响，可以提高爱因斯坦-德西特的情况下的Om = 1的可能性，并讨论其可观察到的签名。
The mean intracluster gas fraction of X-ray clusters within their hydrostatic regions is derived from recent observational compilations of David, Jones & Forman and White & Fabian. At radii encompassing a mean density 500 times the critical value, the individual sample bi-weight means are moderately (2.4er) discrepant; revising binding masses with a virial relation calibrated by numerical simulations removes the discrepancy and results in a combined sample mean and standard error !gas(rsoo) = (0.060 ± 0.003) h -312. For hierarchical clustering models with an extreme physical assumption to maximize cluster gas content, this value constrains the universal ratio of total, clustered-to-baryonic mass ~/~ :::;;23.1 h3/Z. Combining this with a maximal value of ~ from primordial nucleosynthesis results in ~ h 1/Z < 0.76. A more physically plausible approach based on low deuterium abundance inferences from quasar absorption spectra and accounting for baryons within cluster galaxies yields an estimate of ~ hZ/ 3 = 0.30 ± 0.07, with sources of systematic error involved in the derivation providing approximately 30 per cent additional uncertainty. Other effects which could enhance the likelihood of the Einstein-de Sitter case Om = 1 are presented, and their observable signatures discussed.