Prospects for cosmic magnification measurements using H I intensity mapping

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Date

2020

Journal Title

Journal ISSN

Volume Title

Publisher

Oxford University Press

Abstract

We investigate the prospects of measuring the cosmic magnification effect by cross-correlating neutral hydrogen intensity mapping (H I IM) maps with background optical galaxies. We forecast the signal-to-noise ratio for H i IM data from SKA1-MID and HIRAX, combined with LSST photometric galaxy samples. We find that, thanks to their different resolutions, SKA1-MID and HIRAX are highly complementary in such an analysis. We predict that SKA1-MID can achieve a detection with a signal-to-noise ratio of ∼15 on a multipole range of ℓ ≲ 200, while HIRAX can reach a signal-to-noise ratio of ∼50 on 200 < ℓ < 2000. We conclude that measurements of the cosmic magnification signal will be possible on a wide redshift range with foreground H I intensity maps up to z ≲ 2, while optimal results are obtained when 0.6 ≲ z ≲ 1.3.

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Keywords

Gravitational lensing: weak, Large-scale structure of Universe, H I intensity mapping, Cosmic magnification, Radio galaxy surveys

Citation

Witzemann, A. et al. (2020). Prospects for cosmic magnification measurements using H I intensity mapping. Monthly Notices of the Royal Astronomical Society, 496( 2), 1959–1966