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arXiv 0906.3867astro-ph.CO
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用团簇质量函数约束宇宙学参数

Constraints on the Cosmological parameters by means of the clusters mass function

A. Del Popolo

摘要:

我们提出的限制值的$Ω_m$,$n$,$σ_8$,从测量的星系团的X射线光度函数编译EMSS,RDCS和BCS星系团样本。用$Ω_m=0.25^{+0.15}_{-0.05}$、$n=-1^{+0.05}_{-0.05}$和$σ_8=0.8^{+0.1}_{-0.1}$得到的数值与WMAP数据一致。然后,我们把约束引用的参数和暗能量状态方程参数,$w$,使用钱德拉观测的37个集群$<z>$ =0.55来自400度$^2$ ROSAT偶然调查和49个最亮的$z \simeq 0.05$集群中检测到的全天调查。在$Λ$ CDM模型的情况下,我们得到$Ω_m=0.25^{+0.1}_{-0.08}$和$σ_8=0.75^{+0.08}_{-0.05}$,而在$w$ CDM模型的情况下,我们得到$Ω_m=0.28^{+0.10}_{-0.10}$,$w=-1.25^{+0.30}_{-0.35}$和$σ_8=0.8^{+0.09}_{-0.09}$。我们的结果是一致的,从最近的分析Ia型超新星,宇宙微波背景各向异性,X射线气体质量分数的放松星系团,重子声振荡和宇宙剪切。从EMSS、RDCS和BCS到Chandra观测的数据质量的改善导致约束的改善,即使不是数据改善的同一实体。

英文摘要:

We present constraints on the values of $Ω_m$, $n$, $σ_8$, obtained from measurements of the X-ray luminosity function of galaxy clusters as compiled in EMSS, RDCS and BCS galaxy cluster samples. The values obtained $Ω_m=0.25^{+0.15}_{-0.05}$, $n=-1^{+0.05}_{-0.05}$, and $σ_8=0.8^{+0.1}_{-0.1}$ are in agreement with WMAP data. We then put constraints on the quoted parameters and the dark-energy equation-of-state parameter, $w$, using Chandra observations of 37 clusters with $<z>$=0.55 derived from 400 deg$^2$ ROSAT serendipitous survey and 49 brightest $z \simeq 0.05$ clusters detected in the All-Sky Survey. In the case of $Λ$CDM model, we get $Ω_m=0.25^{+0.1}_{-0.08}$ and $σ_8=0.75^{+0.08}_{-0.05}$, while in the case of the $w$CDM model, we get $Ω_m=0.28^{+0.10}_{-0.10}$, $w=-1.25^{+0.30}_{-0.35}$, and $σ_8=0.8^{+0.09}_{-0.09}$. Our results are consistent with those from recent analyses of type Ia supernovae, cosmic microwave background anisotropies, the X-ray gas mass fraction of relaxed galaxy clusters, baryon acoustic oscillations and cosmic shear. The improvement in data quality from EMSS, RDCS, and BCS to Chandra observations leads to an improvement in the constraints even if not of the same entity of the improvement in data.

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