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Lookup NU author(s): Dr Joachim Harnois-DerapsORCiD
This is the final published version of an article that has been published in its final definitive form by Oxford University Press, 2022.
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© 2022 The Author(s).The magnification of galaxies in modern galaxy surveys induces additional correlations in the cosmic shear, galaxy-galaxy lensing, and clustering observables used in modern lensing '3 × 2 pt' analyses, due to sample selection. In this paper, we emulate the magnification contribution to all three observables utilizing the SLICS simulations suite, and test the sensitivity of the cosmological model, galaxy bias, and redshift distribution calibration to un-modelled magnification in a Stage-IV-like survey using Monte Carlo sampling. We find that magnification cannot be ignored in any single or combined observable, with magnification inducing >1σ biases in the w0-σ8 plane, including for cosmic shear and 3 × 2 pt analyses. Significant cosmological biases exist in the 3 × 2 pt and cosmic shear from magnification of the shear sample alone. We show that magnification induces significant biases in the mean of the redshift distribution where a position sample is analysed, which may potentially be used to identify contamination by magnification.
Author(s): Duncan CAJ, Harnois-Deraps J, Miller L, Langedijk A
Publication type: Article
Publication status: Published
Journal: Monthly Notices of the Royal Astronomical Society
Year: 2022
Volume: 515
Issue: 1
Pages: 1130-1145
Print publication date: 01/09/2022
Online publication date: 30/06/2022
Acceptance date: 21/06/2022
Date deposited: 15/09/2022
ISSN (print): 0035-8711
ISSN (electronic): 1365-2966
Publisher: Oxford University Press
URL: https://doi.org/10.1093/mnras/stac1809
DOI: 10.1093/mnras/stac1809
ePrints DOI: 10.57711/ag72-mp72
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