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arXiv 1010.2291astro-ph.CO
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精华模型中的簇数计数

Cluster number counts in quintessence models

Seokcheon Lee, Kin-Wang Ng

摘要:

尽管星系团的丰度和演化已经被用来研究宇宙学参数,包括暗能量的性质,因为它们纯粹依赖于宇宙的几何形状和功率谱,但有必要特别注意暗能量对分析的影响。我们得到了显式的暗能量依赖的{ \it rms}线性质量涨落$σ_8$,这是符合CMB归一化小于$2$ %的误差一般恒定的暗能量状态方程,$\oQ$。因此,我们在$σ_8$和物质能量密度对比度$\Omo$之间没有任何简并。当我们将最近获得的临界密度阈值$δ_{c} = 1.58$的正确值\cite{09090826, 09100126}用于Press-Schechter(PS)形式体系中的簇数密度$n$计算时,与通过使用$δ_{c} = 1.69$获得的簇数密度相比,$n$分别在$z = 0$、$0.5$和$1$处增加约$60$、$80$和$110$ %。因此,PS形式主义预测的集群数与模拟和观察到的数据在高质量区域。我们还介绍了Sheth-Tormen(ST)形式主义,这是最近建议的质量函数\cite{10052239}一致的改进系数。我们发现,由$Δ\oQ = -0.1$改变$\oQ$从$\oQ = -1.0$导致$M = 10^{16} h^{-1} M_{\odot}$的高质量团簇的共动数目的改变,分别约为$z = 0$和$1$的$40$ %。

英文摘要:

Even though the abundance and evolution of clusters have been used to study the cosmological parameters including the properties of dark energy owing to their pure dependence on the geometry of the Universe and the power spectrum, it is necessary to pay particular attention to the effects of dark energy on the analysis. We obtain the explicit dark energy dependent {\it rms} linear mass fluctuation $σ_8$ which is consistent with the CMB normalization with less than $2$ % errors for general constant dark energy equation of state, $\oQ$. Thus, we do not have any degeneracy between $σ_8$ and the matter energy density contrast $\Omo$. When we use the correct value of the critical density threshold $δ_{c} = 1.58$ obtained recently \cite{09090826, 09100126} into the cluster number density $n$ calculation in the Press-Schechter (PS) formalism, $n$ increases as compared to the one obtained by using $δ_{c} = 1.69$ by about $60$, $80$, and $110$ % at $z = 0$, $0.5$, and $1$, respectively. Thus, PS formalism predicts the cluster number consistent with both simulation and observed data at the high mass region. We also introduce the improved coefficients of Sheth-Tormen (ST) formalism, which is consistent with the recently suggested mass function \cite{10052239}. We found that changing $\oQ$ by $Δ\oQ = -0.1$ from $\oQ = -1.0$ causes the changing of the comoving numbers of high mass clusters of $M = 10^{16} h^{-1} M_{\odot}$ by about $20$ and $40$ % at $z = 0$ and $1$, respectively.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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