filtering) model and its step function approximation with τ ≃ 0.1017 (resp. The relative difference between the results based on the suppression (resp. In the bottom panel we show also δ SH,F H computed by replacing the two considered models with those obtained assuming the simple step function implemented in the public CMBFAST code for the reionization history (thin solid lines) for the corresponding values of optical depth. In the top panel we report also for comparison the APS from a potential residual foreground (dot-dashes) corresponding to different values of f : 0.1 (dashed line), 0.03 (dots-dashed line), 0.01 (three dots-dashed line), and 0.003 (long dashes). 2 (thick solid lines) compared with the cosmic and sampling variance limitation corresponding to a sky coverage of ≃ 74 per cent (region between the dotted lines). Relative difference, δ S,F, between the (EE mode) APS of CMB anisotropies for the suppression and filtering models reported in Fig. The main limitations come from foreground contamination: it should be subtracted at per cent level in terms of APS, a result potentially achievable by novel component separation techniques and mapping of Galactic foreground. For the EE mode the differences between these models are significantly larger than the cosmic and sampling variance over the multipole range l = 5-15, leaving a good chance of discriminating between these feedback mechanisms with forthcoming/future CMB polarization experiments. Through the dedicated Boltzmann code CMBFAST, modified to include the above ionization histories, we compute the CMB angular power spectrum (APS) of the TT, TE, and EE modes. However, the value of u = 1.69 * 10^-7 (9.65 * 10^-8) for the suppression (filtering) model is in the detectability range of the next generation of CMB spectrum experiments. The derived Comptonization, u, and free-free distortion, y_B, parameters are below current observational limits for both models. The models imply different ionization and thermal histories and 21 cm background signals. We compute the imprints left on the CMB by two cosmic reionization models consistent with current observations but characterized by alternative radiative feedback prescriptions (suppression and filtering) resulting in a different suppression of star formation in low-mass halos.
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