论文标题
使用HAROS之外的暗物质分布重建HI功率谱，并使用最小参数
Reconstructing HI power spectrum with minimal parameters using the dark matter distribution beyond halos
论文作者
论文摘要
通过几个射电望远镜实验对21 cm线的强度映射将探测在重新电位时期的宇宙大规模结构。它需要一个中性氢（HI）聚类的理论框架，例如Baryon声学振荡（BAO）分析的HI功率谱进行建模。我们提出了一种使用N体模拟从暗物质分布中重建HI MAP的新方法。一些研究试图通过将HI气体粘贴到暗物质晕中心，以使用N体仿真来计算HI功率谱，假设Halo和HI质量之间的关系。另一方面，本文提出的方法从晕圈中心的特定尺度上截断了模拟的暗物质分布的HI功率谱。使用此方法，HI功率谱的斜率在BAO尺度上很好地复制了，$ k <1 h/{\ rm mpc} $。此外，我们发现自旋温度的波动（通常在重新电位时期被忽略），在功率谱中最多将亮度温度的功率谱最多调高。最后，我们通过比较暗物质周围的HI和暗物质的密度曲线来讨论我们的方法的工作原理。
Intensity mapping of 21-cm line by several radio telescope experiments will probe the large-scale structure of the Universe in the post-reionization epoch. It requires a theoretical framework of neutral hydrogen (HI) clustering, such as modelling of HI power spectrum for Baryon Acoustic Oscillations (BAO) analysis. We propose a new method for reconstructing the HI map from dark matter distribution using N-body simulations. Several studies attempt to compute the HI power spectrum with N-body simulations by pasting HI gas at the dark matter halo centre, assuming the relation between the halo and HI masses. On the other hand, the method proposed in this paper reproduces the HI power spectrum from simulated dark matter distribution truncated at specific scales from the halo centre. With this method, the slope of HI power spectrum is reproduced well at the BAO scales, $k<1 h/{\rm Mpc}$. Furthermore, we find the fluctuation of spin temperature, which is often ignored at the post-reionization epoch, alters the power spectrum of brightness temperature by at most 8% in the power spectrum. Finally, we discuss how our method works by comparing the density profiles of HI and dark matter around the dark matter halos.
