DECONSTRUCTING THE KINETIC SZ POWER SPECTRUM
DECONSTRUCTING THE KINETIC SZ POWER SPECTRUM
复制标题
DOI：
10.1088/0004-637x/756/1/15
复制
发表时间：
2011-09
期刊：
影响因子：
--
通讯作者：
L. Shaw;D. Rudd;D. Nagai
中科院分区：
文献类型：
--
作者：
L. Shaw;D. Rudd;D. Nagai
我们详细研究了天体物理过程对再电离后时期动力学SZ（kSZ）功率谱的形状和幅度的影响。这是通过构建一个新的kSZ功率谱模型来实现的，我们根据流体动力学模拟的结果对该模型进行了校准。通过构建该模型，我们的方法考虑了所有相关的密度和速度模式，因此不受模拟盒子尺寸有限的影响。我们发现，辐射冷却和恒星形成在ℓ = 3000时可使kSZ功率谱的幅度降低多达33%，即1 μK²。这是由于气体转化为恒星导致星系团和星系群中平均气体密度降低所驱动的。氦再电离发生的红移变化可使幅度产生类似比例的影响，而当前对宇宙学参数（即σ8）的限制使kSZ功率谱又产生了±15%的不确定性。我们展示了通过kSZ层析成像测量信号的红移依赖性，如何能够约束本文所提出的模型——从而降低kSZ信号的天体物理不确定性。最后，我们讨论了这项工作的结果如何通过对非均匀（或斑块状）再电离所产生的kSZ信号的测量来帮助约束再电离的持续时间。
We present a detailed investigation of the impact of astrophysical processes on the shape and amplitude of the kinetic SZ (kSZ) power spectrum from the post-reionization epoch. This is achieved by constructing a new model of the kSZ power spectrum which we calibrate to the results of hydrodynamic simulations. By construction, our method accounts for all relevant density and velocity modes and so is unaffected by the limited box size of our simulations. We find that radiative cooling and star formation can reduce the amplitude of the kSZ power spectrum by up to 33% or 1 μK2 at ℓ = 3000. This is driven by a decrease in the mean gas density in groups and clusters due to the conversion of gas into stars. Variations in the redshifts at which helium reionization occurs can effect the amplitude by a similar fraction, while current constraints on cosmological parameters (namely σ8) translate to a further ±15% uncertainty on the kSZ power spectrum. We demonstrate how the models presented in this work can be constrained—reducing the astrophysical uncertainty on the kSZ signal—by measuring the redshift dependence of the signal via kSZ tomography. Finally, we discuss how the results of this work can help constrain the duration of reionization via measurements of the kSZ signal sourced by inhomogeneous (or patchy) reionization.