Precision era of the kinetic Sunyaev-Zeldovich effect: simulations, analytical models and observations and the power to constrain reionization

The kinetic SZ effect, which is the dominant CMB source at arc-minute scale and ν ∼ 217 Ghz, probes the ionized gas peculiar momentum up to the epoch of reionization and is a sensitive measure of the reionization history. We ran high resolution self-similar and ΛCDM hydro simulations and built an analytical model to study this effect. Our model reproduces the ΛCDM simulation results to several percent accuracy. We tested our model against self-similar simulations, and found a wider range of applicability than all previous analytical models. Our model in its continuous version is free of simulation limitations such as finite simulation box and finite resolution and allows an accurate prediction of the kinetic SZ power spectrum Cl. For the WMAP cosmology (Spergel et al. 2003), we find lCl/(2π) ≃ 0.91 × 10 [(1 + zreion)/10] (l/5000)reion for the reionization redshift zreion ∈ [6, 20] and l ∈ [3000, 9000]. The corresponding temperature fluctuation is several μK at these ranges. The dependence of Cl on the reionization history allows an accurate measurement of the reionization epoch. For the Atacama cosmology telescope experiment, Cl can be measured with better than 1% accuracy. This precision measurement of the kinetic SZ effect will constrain zreion with better than 3% accuracy. Complicated reionization scenarios degenerated in the primary CMB temperature measurement can be distinguished with ∼ 10σ confidence depending on the detail of the reionization history.