发表机构
Université Paris-Saclay, CNRS, Institut d’Astrophysique Spatiale（巴黎萨克雷大学、法国国家科学研究中心、天体物理研究所）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究提出基于流体动力学模拟校准的解析模型，推导再电离时期CMB三种可观测量的自谱，可被下一代CMB实验探测，其联合分析可约束再电离历史与形态。
AI 中文摘要
再电离时期通过两种效应将其历史与形态印记在宇宙微波背景（CMB）的温度与偏振各向异性上：运动学Sunyaev-Zel'dovich（kSZ）效应与汤姆孙散射。为对这些可观测量进行联合分析并对再电离历史与形态施加严格约束，需要一个通用的再电离模型。我们提出一种快速、物理上精确的解析方法，用于自洽推导三种主要印记的角功率谱：汤姆孙光学深度的空间涨落、 patchy kSZ效应以及散射与屏蔽B模。该方法与现有解析模型不同，它基于高分辨率流体动力学模拟校准，并依赖于再电离的物理参数。我们预测的功率谱与宇宙学模拟得到的结果一致，同时包含更多物理信息，如电离气泡的典型尺寸和再电离的持续时间。我们提供了更新后的可探测性评估，表明类似CMB Stage 4的实验可测量$C_\tau^\tau$，而类似CMB-HD的实验可测量$C_\text{BB}^\text{BB}$。我们展示了三种可观测量在约束再电离历史与形态方面的互补性，并说明它们的联合分析有望获得再电离的全局图景。该解析模型将成为分析即将到来的CMB数据的有力工具，可单独使用或与高红移21cm信号测量等独立数据集结合使用。推导这些功率谱的代码作为preion Python包在网上公开可用。
英文摘要
The Epoch of Reionisation imprints its history and morphology on the Cosmic Microwave Background temperature and polarisation anisotropies through two effects: The kinetic Sunyaev Zel'dovich (kSZ) effect and Thomson scattering. To perform joint analyses of these observables and put tight constraints on the reionisation history and morphology, a common reionisation model is necessary. We present a quick, physically-accurate analytical approach to derive consistently the angular power spectra of the three main resulting imprints that are the spatial fluctuations of the Thomson optical depth, the patchy kSZ effect, and the scattering and screening B-modes. The approach differs from existing analytical models, as it is calibrated on high-resolution hydrodynamical simulations and depends on physical parameters of reionisation. Our predicted power spectra are consistent with the ones derived from cosmological simulations, whilst including more physical information -- such as the typical size of ionised bubbles and the duration of reionisation. We provide an updated detectability assessment and show that both $C_\ell^{ττ}$ and $C_\ell^{BB}$ could be measured by experiments similar to CMB Stage 4 and CMB-HD, respectively. We show the complementarity of the three observables in constraining reionisation history and morphology, and illustrate the potential of their joint analysis to get a global picture of reionisation. This analytical model will be a powerful tool in the analysis of upcoming CMB data, either alone or in combination with independent datasets such as measurements of the high-redshift 21cm signal. The code to derive these spectra is publicly available online as the preion Python package.
Comments11 pages, 6 figures, code available at https://github.com/adeliegorce/preion, comments welcome
