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arXiv · 1811.05012

The Cross-correlation of KSZ Effect and 21 cm Intensity Mapping with Tidal Reconstruction

Dongzi Li·Hong-Ming Zhu·Ue-Li Pen
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Abstract

We discuss the possibility of studying diffuse baryon distributions with kinematic Sunyaev-Zel'dovich (kSZ) effect by correlating cosmic microwave background (CMB) temperature fluctuations with density fluctuations from 21\,cm intensity mapping (IM). The biggest challenge for the cross-correlation is the loss of large-scale information in IM, due to foregrounds and the zero spacing problem of interferometers. We apply the tidal reconstruction algorithm to restore the lost large-scale modes, which increases the correlation by more than a factor of three. With the predicted foreground level, we expect a $\sim20\,σ$ detection of kSZ signal for $0.8\lesssim z\lesssim2.5$ with CHIME and Planck, and a $\sim40\, σ$ detection with HIRAX and Planck. The significance can be greatly increased with next-generation facilities of higher spatial resolutions.

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Dongzi Li, Hong-Ming Zhu, Ue-Li Pen. 2018-11-12. The Cross-correlation of KSZ Effect and 21 cm Intensity Mapping with Tidal Reconstruction. https://doi.org/10.1103/physrevd.100.023517

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