Cosmological Constraints from the ROSAT Deep Cluster Survey
Cosmological Constraints from the ROSAT Deep Cluster Survey
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ROSAT 深星团巡天的宇宙学约束
DOI：
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发表时间：
1999
期刊：
影响因子：
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通讯作者：
C. Norman
中科院分区：
文献类型：
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作者：
S. Borgani;P. Rosati;P. Tozzi;C. Norman
ROSAT深星系团巡天（RDCS）提供了一个新的X射线选择星系团的大型深样本。这里使用通量计数n（S）、红移分布n（z）和大红移基线（z 0.8）上的X射线光度函数（XLF）等可观测量来约束宇宙学模型。我们的分析是基于Press-Schechter方法，其可靠性进行了测试，对N体模拟。遵循唯象的方法，没有假设是由一个先验的集群质量和观测到的X射线光度之间的关系。作为第一步，我们使用来自RDCS的局部XLF，沿着使用来自Brilliant星团巡天的XLF提供的高光度扩展，以限制功率谱的幅度σ8和局部光度-温度关系的形状Lbol-T。在90%置信水平下，我们得到了平坦模型（ΩΛ=1-Ω0）的σ8=（0.58 ± 0.06）× Ω0-0.47+0.16Ω，开放模型（ΩΛ=0）的σ8=（0.58 ± 0.06）× Ω0-0.53+0.27Ω，几乎与Lbol-T形状无关。密度参数Ω0和Lbol-T关系的演化受z>0时的RDCS XLF和z =0.33时的EMSS XLF以及RDCS n（S）和n（z）分布的约束。通过将Lbol-T关系的振幅演化建模为（1+z）A，在90%的置信水平下，Ω0=1模型可以适应XLF的演化，其中1 <$A <$3，而Ω0=0.4+0.3−0.2和Ω0 <$0.6分别由开放和平坦模型的非演化Lbol-T（A=0）暗示。
The ROSAT Deep Cluster Survey (RDCS) has provided a new large deep sample of X-ray selected galaxy clusters. Observables such as the flux number counts n(S), the redshift distribution n(z), and the X-ray luminosity function (XLF) over a large redshift baseline (z≲0.8) are used here in order to constrain cosmological models. Our analysis is based on the Press-Schechter approach, whose reliability is tested against N-body simulations. Following a phenomenological approach, no assumption is made a priori on the relation between cluster masses and observed X-ray luminosities. As a first step, we use the local XLF from RDCS, along with the high-luminosity extension provided by the XLF from the Brightest Cluster Survey, in order to constrain the amplitude of the power spectrum, σ8, and the shape of the local luminosity-temperature, Lbol-T, relation. We obtain σ8=(0.58 ± 0.06) × Ω0-0.47+0.16Ω for flat models (ΩΛ=1-Ω0) and σ8=(0.58 ± 0.06) × Ω0-0.53+0.27Ω for open models (ΩΛ=0) at a 90% confidence level, almost independent of the Lbol-T shape. The density parameter Ω0 and the evolution of the Lbol-T relation are constrained by the RDCS XLF at z>0 and the EMSS XLF at z̄=0.33, and by the RDCS n(S) and n(z) distributions. By modeling the evolution for the amplitude of the Lbol-T relation as (1+z)A, an Ω0=1 model can be accommodated for the evolution of the XLF with 1≲A≲3 at a 90% confidence level, while Ω0=0.4+0.3−0.2 and Ω0≲0.6 are implied by a nonevolving Lbol-T (A=0) for open and flat models, respectively.