Figure 9

Figure 9: Temperature fluctuations ( $ΔT ∕T$ ) in the CMBR due to the primary Sachs–Wolfe (SW) effect and secondary integrated SW, Doppler, and Thomson scattering effects in a critically closed model. The top two plates are results with no reionization and baryon fractions 0.02 (plate 1, $∘ ∘ 4 × 4$ , $−5 ΔT ∕T|rms = 2.8 × 10$ ), and 0.2 (plate 2, $∘ ∘ 8 × 8$ , $−5 ΔT ∕T |rms = 3.4 × 10$ ). The bottom two plates are results from an “early and gradual” reionization scenario of decaying neutrinos with baryon fraction 0.02 (plate 3, $4∘ × 4∘$ , $ΔT ∕T |rms = 1.3 × 10−5$ ; and plate 4, $8∘ × 8∘$ , $ΔT ∕T |rms = 1.4 × 10−5$ ). If reionization occurs, the scattering probability increases and anisotropies are damped with each scattering event. At the same time, matter structures develop large bulk motions relative to the comoving background and induce Doppler shifts on the CMB. The imprint of this effect from last scattering can be a significant fraction of primary anisotropies.