The shape of dark matter haloes: results from weak lensing in the Ultraviolet Near-Infrared Optical Northern Survey (UNIONS)
ArXiv 2209.09088 (2022)
Measurement and modelling of the chromatic dependence of a reflected wavefront on the Euclid space telescope dichroic mirror
Proceedings of SPIE--the International Society for Optical Engineering SPIE, the international society for optics and photonics 12180 (2022) 121804v-121804v-12
On cosmological bias due to the magnification of shear and position samples in modern weak lensing analyses
Monthly Notices of the Royal Astronomical Society Oxford University Press 515:1 (2022) 1130-1145
Abstract:
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 “3x2pt” analyses, due to sample selection. In this paper, we emulate the magnification contribution to all three observables utilising 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 3x2pt analyses. Significant cosmological biases exist in the 3x2pt 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.Euclid preparation
Astronomy & Astrophysics EDP Sciences 662 (2022) a112
ShapePipe: a new shape measurement pipeline and weak-lensing application to UNIONS/CFIS data
ArXiv 2204.04798 (2022)