标题： LiteBIRD 科学目标和预测。 绘制宇宙中的热气体。 显示英文标题

标题： LiteBIRD Science Goals and Forecasts. Mapping the Hot Gas in the Universe

摘要： 我们评估LiteBIRD任务通过热Sunyaev-Zeldovich (SZ)效应绘制宇宙中热气体分布的能力。 我们的分析依赖于综合模拟，包括各种银河系和河外前景发射源，同时考虑了LiteBIRD的特定仪器特性，如探测器灵敏度、频率相关的光束卷积、不均匀的天空扫描和$1/f$噪声。 我们实施了一个定制的组分分离管道，以在98%的天空范围内绘制热SZ康普顿$y$参数。 尽管在星系团科学方面角分辨率较低，LiteBIRD提供了全天空覆盖，并且与普朗克卫星相比，具有更高的灵敏度以及更多的频率波段，从而能够构建一个全天空的$y$图，其在大和中等角尺度上的前景污染更少。 通过在组分分离管道中结合LiteBIRD和普朗克通道，我们获得了一个最优的$y$图，该图利用了两个实验的优势，普朗克通道的更高角分辨率使得能够恢复超出LiteBIRD光束限制的紧凑星系团，而众多敏感的LiteBIRD通道进一步减轻了前景污染。 通过检查地图、功率谱和各种天空成分的一点统计量，突出了LiteBIRD的附加值。 在组分分离之后，LiteBIRD的$1/f$噪声在所有多极数下都有效抑制，低于热SZ信号。 从LiteBIRD-普朗克组合的$y$图功率谱中获得的$S_8=\sigma_8\left(\Omega_{\rm m}/0.3\right)^{0.5}$宇宙学约束相比仅从普朗克获得的约束，不确定性减少了15%。 这种改进可以归因于LiteBIRD-Planck组合的$y$图中可用的未污染天空比例增加。 显示英文摘要

摘要： We assess the capabilities of the LiteBIRD mission to map the hot gas distribution in the Universe through the thermal Sunyaev-Zeldovich (SZ) effect. Our analysis relies on comprehensive simulations incorporating various sources of Galactic and extragalactic foreground emission, while accounting for specific instrumental characteristics of LiteBIRD, such as detector sensitivities, frequency-dependent beam convolution, inhomogeneous sky scanning, and $1/f$ noise. We implement a tailored component-separation pipeline to map the thermal SZ Compton $y$-parameter over 98% of the sky. Despite lower angular resolution for galaxy cluster science, LiteBIRD provides full-sky coverage and, compared to the Planck satellite, enhanced sensitivity, as well as more frequency bands to enable the construction of an all-sky $y$-map, with reduced foreground contamination at large and intermediate angular scales. By combining LiteBIRD and Planck channels in the component-separation pipeline, we obtain an optimal $y$-map that leverages the advantages of both experiments, with the higher angular resolution of the Planck channels enabling the recovery of compact clusters beyond the LiteBIRD beam limitations, and the numerous sensitive LiteBIRD channels further mitigating foregrounds. The added value of LiteBIRD is highlighted through the examination of maps, power spectra, and one-point statistics of the various sky components. After component separation, the $1/f$ noise from LiteBIRD is effectively mitigated below the thermal SZ signal at all multipoles. Cosmological constraints on $S_8=\sigma_8\left(\Omega_{\rm m}/0.3\right)^{0.5}$ obtained from the LiteBIRD-Planck combined $y$-map power spectrum exhibits a 15% reduction in uncertainty compared to constraints from Planck alone. This improvement can be attributed to the increased portion of uncontaminated sky available in the LiteBIRD-Planck combined $y$-map.