http://arxiv.org/abs/2301.04445
Neutral hydrogen (HI) intensity mapping (IM) survey is generally regarded as a promising tool to explore the expansion history of the universe. In this work, we investigate the capability of MeerKAT HI IM observation in interferometric mode to estimate the power spectrum and constrain cosmological parameters in typical dark energy models. Besides, a novel approach of delay spectrum is employed, which can achieve separating the weak HI signal from the foreground in the frequency space. We find that the different survey fields have a great influence on the fractional errors on power spectrum $\Delta P/P$ in a limited observational time of 10 h. With the integration time increasing from 10 h to 10000 h, $\Delta P/P$ becomes distinctly smaller until the cosmic variance begins to dominate. In the total 10000 h observation, the lower $\Delta P/P$ in low $k$ can be achieved when tracking 100 points for MeerKAT L-band and 10 points for MeerKAT UHF-band. Through simulating 10000 h HI IM survey, we obtain $\sigma(\Omega_{\rm m})=0.044$ and $\sigma(H_0)=2.8~{\rm km\ s^{-1}\ Mpc^{-1}}$ with MeerKAT L-band, which are worse than the results of $\sigma(\Omega_{\rm m})=0.028$ and $\sigma(H_0)=2.0~{\rm km\ s^{-1}\ Mpc^{-1}}$ with MeerKAT UHF-band in the $\Lambda$CDM model. However, in the $w$CDM and CPL models, MeerKAT shows a limited capability of constraining dark-energy equation of state, even though combined with Planck data. Our analysis is shown to be a useful guide for the near future MeerKAT observations in HI IM survey.
M. Zhang, Y. Li, J. Zhang, et. al.
Thu, 12 Jan 23
37/68
Comments: 10 pages, 10 figures
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