文章基本信息

标题：Improved constraints on reionisation from CMB observations: A parameterisation of the kSZ effect
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作者：A. Gorce ; S. Ilić ; M. Douspis 等
期刊名称：Astronomy & Astrophysics
印刷版ISSN：0004-6361
电子版ISSN：1432-0746
出版年度：2020
卷号：640
页码：1-14
DOI：10.1051/0004-6361/202038170
语种：English
出版社：EDP Sciences
摘要：We show that, in the context of patchy reionisation, an accurate description of the angular power spectrum of the kinetic Sunyaev–Zel’dovich (kSZ) effect is not possible with simple scaling relations between the amplitude of the spectrum and global parameters, such as the reionisation midpoint and its duration. We introduce a new parameterisation of this spectrum, based on a novel description of the power spectrum of the free electrons density contrastPee(k, z) in terms of the reionisation global history and morphology. We directly relate features of the spectrum to the typical ionised bubble size at different stages in the process and, subsequently, to the angular scale at which the patchy kSZ power spectrum reaches its maximum. We successfully calibrated our results on a custom set of advanced radiative hydrodynamical simulations and later found our parameterisation to be a valid description of a wide range of other simulations and, therefore, reionisation physics. In the end, and as long as the global reionisation history is known, two parameters are sufficient to derive the angular power spectrum. Such an innovative framework applied to cosmic microwave background data and combined with 21 cm intensity mapping will allow a first consistent detection of the amplitude and shape of the patchy kSZ signal, giving in turn access to the physics of early light sources.
关键词：enmethods: analyticalcosmic background radiationdark agesreionizationfirst stars