Reionization on Large Scales. Iii. Predictions for Low-ℓ Cosmic Microwave Background Polarization and High-ℓ Kinetic Sunyaev-zel'dovich Observables

Abstract

We present new predictions for cosmic microwave background (CMB) temperature (on small angular scales) and polarization (on large angular scales) anisotropies induced during the epoch of reionization (EoR). Using a novel method calibrated from radiation-hydrodynamic simulations, we model the EoR in large volumes (L greater than or similar to 2Gpc h(-1)). We find that the EoR contribution to the kinetic Sunyaev-Zel'dovich power spectrum (patchy kSZ) ranges between similar to 0.6-2.8 mu K-2 at l = 3000 for the explored parameter space. For each model, the patchy kSZ power spectrum is calculated from three large 15 degrees x 15 degrees maps for better numerical convergence. Decreasing the size of these maps biases the overall patchy kSZ power to higher values. We find that the amplitude of the patchy kSZ power spectrum at l = 3000 follows simple scalings of D-l=3000(kSZ) alpha (z) over bar and D(l=3000)kSZ alpha Delta(0.51)(z) for the mean redshift ((z) over bar) and duration (Delta(z)) of reionization. Using the constraints on (z) over barz from the Wilkinson Microwave Anisotropy Probe seven year results and the lower limit on Delta(z) from EDGES, we find a lower limit of similar to 0.4 mu K-2 at l = 3000. Planck will infer the mean redshift from the Thomson optical depth imprinted in the low-l polarization power spectrum. Future measurements of the high-l CMB power spectrum from the Atacama Cosmology Telescope and South Pole Telescope should detect the patchy kSZ signal if the cross correlation between the thermal SZ effect and the cosmic infrared background is constrained. We show that the combination of temperature and polarization measurements constrains both (z) over bar and Delta(z). The patchy kSZ maps, power spectra templates, and the polarization power spectra will be publicly available.