H i IM correlation function from UNIT simulations: BAO and observationally induced anisotropy
H i IM correlation function from UNIT simulations: BAO and observationally induced anisotropy
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UNIT 模拟中的 Hi IM 相关函数：BAO 和观测引起的各向异性
DOI：
10.1093/mnras/stab3406
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发表时间：
2022
影响因子：
4.8
通讯作者：
Avila S
中科院分区：
文献类型：
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作者：
Avila S
我们研究了由模拟产生的高强度图（IM）的聚类，重点是重子声学振荡（BAOs）和望远镜光束平滑和前景清洗引起的影响。我们首先基于应用于UNIT模拟的半解析星系演化（SAGE）模型创建了一个Hicatalogue atz= 1.321。利用这一目录，我们研究了模型H与暗物质晕之间的关系，并研究了该模型预测的Hi， $\Omega _\rm{H \ \small {\rm I}}$的丰度。然后，我们使用最近网格点方法创建合成HiIM。为了模拟望远镜光束效应，在垂直于视线的平面上进行高斯平滑。通过在径向方向上指数阻尼最大波长傅里叶模式来模拟前景去除方法的效果。我们研究了各向异性2点相关函数(2PCF) ξ(r⊥,r∥)以及它如何受到上述观测效应的影响。为了更好地隔离BAO信号，我们研究了几种针对系统效应而定制的2pcf μ楔（具有受限的方向μ范围），并将它们与径向2pcf的不同定义进行了比较。最后，我们在类似ska调查的背景下讨论了我们的发现，在这里提出的大多数估计器中发现了明确的BAO信号。
We study the clustering of Hiintensity maps (IM) produced from simulations with a focus on baryonic acoustic oscillations (BAOs) and the effects induced by telescope beam smoothing and foreground cleaning. We start by creating an Hicatalogue atz= 1.321 based on the Semi-Analytic Galaxy Evolution (SAGE) model applied to the UNIT simulations. With this catalogue, we investigate the relation between model Hiand the dark matter haloes and we also study the abundance of Hi, $\Omega _\rm{H \small {\rm I}}$, predicted by this model. We then create synthetic HiIM with a nearest-grid-point approach. In order to simulate the telescope beam effect, a Gaussian smoothing is applied on the plane perpendicular to the line of sight. The effect of foreground removal methods is simulated by exponentially damping the largest wavelength Fourier modes on the radial direction. We study the anisotropic 2-point correlation function (2PCF) ξ(r⊥,r∥) and how it is affected by the aforementioned observational effects. In order to better isolate the BAO signal, we study several 2PCFμ-wedges (with a restricted range of orientationsμ) tailored to address the systematics effects and we compare them with different definitions of radial 2PCFs. Finally, we discuss our findings in the context of an SKA-like survey, finding a clear BAO signal in most of the estimators here proposed.