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تسجيل مستخدم جديدConstraining the ionized gas evolution with CMB-spectroscopic survey cross-correlation
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Yin-Zhe Ma
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We forecast the prospective constraints on the ionized gas model $f_{rm gas}(z)$ at different evolutionary epochs via the tomographic cross-correlation between kinetic Sunyaev-Zeldovich (kSZ) effect and the reconstructed momentum field at different redshifts. The experiments we consider are the Planck and CMB Stage-4 survey for CMB and the SDSS-III for the galaxy spectroscopic survey. We calculate the tomographic cross-correlation power spectrum, and use the Fisher matrix to forecast the detectability of different $f_{rm gas}(z)$ models. We find that for constant $f_{rm gas}$ model, Planck can constrain the error of $f_{rm gas}$ ($sigma_{f_{rm gas}}$) at each redshift bin to $sim 0.2$, whereas four cases of CMB-S4 can achieve $sigma_{f_{rm gas}} sim 10^{-3}$. For $f_{rm gas}(z)=f_{rm gas,0}/(1+z)$ model the error budget will be slightly broadened. We also investigate the model $f_{rm gas}(z)=f_{rm gas,0}/(1+z)^{alpha}$. Planck is unable to constrain the index of redshift evolution, but the CMB-S4 experiments can constrain the index $alpha$ to the level of $sigma_{alpha} sim 0.01$--$0.1$. The tomographic cross-correlation method will provide an accurate measurement of the ionized gas evolution at different epochs of the Universe.
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