kSZ效应的组分分析  

Different Gas Contribution to the Kinetic Sunyaev Zel'dovich Effect

作　　者：苗寒 

机构地区：[1]中国科学院上海天文台星系与宇宙学重点实验室,上海200030 [2]中国科学院大学,北京100049

出　　处：《天文学进展》2016年第1期111-119,共9页Progress In Astronomy

摘　　要：运动学Sunyaev Zel’dovich效应(kSZ效应)是探索失踪重子这一天体物理学核心问题的新兴手段。近期的一系列CMB实验正逐步实现对kSZ效应功率谱的测量,并将在可预见的未来实现精确测量。但是,kSZ功率谱中各气体组分的贡献还缺乏细致的研究,导致其探索失踪重子的能力缺乏量化。通过一组初始条件相同,气体物理不同的流体力学数值模拟,定量地分析了不同的气体组分对kSZ效应的贡献。其中,作为研究失踪重子的热门候选,温热星系际介质对于kSZ功率谱的贡献很大,因此k SZ功率谱是用于寻找宇宙中失踪重子很有效的方法之一。但由于星系团内热气体也贡献相当程度的kSZ功率谱,因此,用kSZ功率谱的观测作为探测和定量分析失踪重子方法,还需要更仔细的分析。The kinetic Sunyaev-Zel＇dovich （kSZ） effect is becoming a possible probe of the missing baryons, owing to the recent advance in CMB experiments and galaxy surveys. The kSZ power spectrum has been detected by various existing experiments, however significant improvement of accuracy is still required. Through a set of hydrodynamic simulations, we quantify the relative contribution of various gas components to the kSZ signals. We find that the warm-hot intergalactic medium （WHIM） contributes significantly to the kSZ power spectrum. This makes the kSZ power spectrum a promising probe of missing baryons. However, we find that contribution from the intracluster medium （ICM） is also significant. Therefore, apart from the difficulties in observational measurements, the interpretation of kSZ power spectrum requires careful investigation in order to reliably constrain the WHIM fraction.

关 键 词：宇宙学 CMB 大尺度结构 SZ效应 

分 类 号：P159[天文地球—天文学]