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arXiv 2004.09979astro-ph.COgr-qchep-phhep-th
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利用类星体X射线和UV通量测量约束宇宙学模型参数

Using quasar X-ray and UV flux measurements to constrain cosmological model parameters

Narayan Khadka, Bharat Ratra

备注：
16 pages, 14 figures. arXiv admin note: text overlap with arXiv:1909.01400, MNRAS in press
发表信息：
MNRAS, 497, 2020, 263
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摘要：

Risaliti和Lusso汇编了1598个红移范围为$0.036 \leq z \leq 5.1003$的类星体（QSO）的X射线和紫外线通量测量结果，其中一部分，$z \sim 2.4 - 5.1$，在宇宙学上基本上是未探测的。在本文中，我们使用这些类星体测量，单独和结合重子声振荡（BAO）和哈勃参数[ $H(z)$ ]测量，约束宇宙学参数在六个不同的宇宙学模型，每个有两个不同的哈勃常数先验。在大多数模型中，考虑到较大的不确定性，类星体宇宙学参数约束大多与$H(z)$ + BAO数据一致。一个重要的例外是非相对论性物质密度参数$Ω_{m0}$，在大多数模型中，类星体数据支持$Ω_{m0} \sim 0.5 - 0.6$。因此，在对类星体数据与$H(z)$ + BAO数据的联合分析中，一维$Ω_{m0}$分布略微向较大值移动。对类星体+ $H(z)$ + BAO数据的联合分析与目前的标准模型，空间平坦的$Λ$ CDM是一致的，但稍微倾向于封闭的空间超曲面和动力学暗能量。由于类星体数据支持的较高$Ω_{m0}$值似乎与这些数据的$z \sim 2 - 5$部分有关，并且与大多数$z < 2.5$数据以及$z \sim 1100$的宇宙微波背景各向异性数据对$Ω_{m0} \sim 0.3$的强烈指示有些冲突，在大多数模型中，较大的类星体数据$Ω_{m0}$可能更能说明$z \sim 2 - 5$类星体数据的问题，而不是标准的平面$Λ$ CDM模型的不足。

英文摘要：

Risaliti and Lusso have compiled X-ray and UV flux measurements of 1598 quasars (QSOs) in the redshift range $0.036 \leq z \leq 5.1003$, part of which, $z \sim 2.4 - 5.1$, is largely cosmologically unprobed. In this paper we use these QSO measurements, alone and in conjunction with baryon acoustic oscillation (BAO) and Hubble parameter [$H(z)$] measurements, to constrain cosmological parameters in six different cosmological models, each with two different Hubble constant priors. In most of these models, given the larger uncertainties, the QSO cosmological parameter constraints are mostly consistent with those from the $H(z)$ + BAO data. A somewhat significant exception is the non-relativistic matter density parameter $Ω_{m0}$ where the QSO data favors $Ω_{m0} \sim 0.5 - 0.6$ in most models. Consequently in joint analyses of QSO data with $H(z)$ + BAO data the one-dimensional $Ω_{m0}$ distributions shift slightly toward larger values. A joint analysis of the QSO + $H(z)$ + BAO data is consistent with the current standard model, spatially-flat $Λ$CDM, but mildly favors closed spatial hypersurfaces and dynamical dark energy. Since the higher $Ω_{m0}$ values favored by the QSO data appear to be associated with the $z \sim 2 - 5$ part of these data, and conflict somewhat with strong indications for $Ω_{m0} \sim 0.3$ from most $z < 2.5$ data as well as from the cosmic microwave background anisotropy data at $z \sim 1100$, in most models, the larger QSO data $Ω_{m0}$ is possibly more indicative of an issue with the $z \sim 2 - 5$ QSO data than of an inadequacy of the standard flat $Λ$CDM model.

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