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 the specific instrumental characteristics of the LiteBIRDmission, 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 Plancksatellite, enhanced sensitivity, as well as more frequency bands to enable the construction of an all-sky thermal SZ y-map, with reduced foreground contamination at large and intermediate angular scales. By combining LiteBIRD and Planck channels in the component-separation pipeline, we also 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 ofLiteBIRD 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 fromLiteBIRD's intensity channels is effectively mitigated below the level of the thermal SZ signal at all multipoles. Cosmological constraints on S8 = σ8 (Ωm/0.3)0.5 obtained from the LiteBIRD-Planck combined y-map power spectrum exhibits a 15 % reduction in uncertainty compared to constraints derived fromPlanck alone. This improvement can be attributed to the increased portion of uncontaminated sky available in the LiteBIRD-Planck combined y-map.

中文翻译：

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LiteBIRD 科学目标和预测。绘制宇宙中的热气体


我们评估了 LiteBIRD 任务的能力，即通过热 Sunyaev-Zeldovich （SZ） 效应绘制宇宙中热气体分布图。我们的分析依赖于综合模拟，其中包含各种银河系和星系外前景发射源，同时考虑了 LiteBIRD 任务的特定仪器特性，例如探测器灵敏度、频率相关光束卷积、非均匀天空扫描和 1/f 噪声。我们实施了定制的组件分离管道，以绘制 98% 天空的热 SZ Compton y 参数。尽管星系团科学的角度分辨率较低，但 LiteBIRD 提供了全天空覆盖，并且与普朗克卫星相比，灵敏度更高，以及更多的频段，从而能够构建全天空热 SZ y 图，减少大和中角度尺度的前景污染。通过在组件分离管道中结合 LiteBIRD 和 Planck 通道，我们还获得了一个最佳的 y 映射，该映射利用了这两个实验的优势，Planck 通道的更高角度分辨率能够在 LiteBIRD 光束限制之外恢复紧凑的团簇，而众多敏感的 LiteBIRD 通道进一步减轻了前景。通过检查地图、功率谱和各种天空分量的单点统计数据，突出了 LiteBIRD 的附加值。元件分离后，来自LiteBIRD强度通道的1/f噪声在所有多极点的热SZ信号水平以下得到有效缓解。S8 = σ8 （Ωm/0.3）0 的宇宙学约束。5 从 LiteBIRD-Planck 组合 y 图功率谱中获得的 5 与单独来自普朗克的约束相比，不确定性降低了 15%。这种改进可归因于 LiteBIRD-Planck 组合 y 地图中可用的未受污染天空部分的增加。