Impact of Point Spread Function Higher Moments Error on Weak Gravitational Lensing II: A Comprehensive Study

Abstract

Weak gravitational lensing, or weak lensing, is one of the most powerful probes for dark matter and dark energy science, although it faces increasing challenges in controlling systematic uncertainties as \edit{the statistical errors become smaller}. The Point Spread Function (PSF) needs to be precisely modeled to avoid systematic error on the weak lensing measurements. The weak lensing biases induced by errors in the PSF model second moments, i.e., its size and shape, are well-studied. However, Zhang et al. (2021) showed that errors in the higher moments of the PSF may also be a significant source of systematics for upcoming weak lensing surveys. Therefore, the goal of this work is to comprehensively investigate the modeling quality of PSF moments from the $3^{\text{rd}}$ to $6^{\text{th}}$ order, and estimate their impact on cosmological parameter inference. We propagate the \textsc{PSFEx} higher moments modeling error in the HSC survey dataset to the weak lensing \edit{shear-shear correlation functions} and their cosmological analyses. We find that the overall multiplicative shear bias associated with errors in PSF higher moments can cause a $\sim 0.1\sigma$ shift on the cosmological parameters for LSST Y10. PSF higher moment errors also cause additive biases in the weak lensing shear, which, if not accounted for in the cosmological parameter analysis, can induce cosmological parameter biases comparable to their $1\sigma$ uncertainties for LSST Y10. We compare the \textsc{PSFEx} model with PSF in Full FOV (\textsc{Piff}), and find similar performance in modeling the PSF higher moments. We conclude that PSF higher moment errors of the future PSF models should be reduced from those in current methods to avoid a need to explicitly model these effects in the weak lensing analysis.

24 pages, 17 figures, 3 tables; Accepted by MNRAS; Comments welcome!

References in corpus (16)

• Wide-Field InfrarRed Survey Telescope-Astrophysics Focused Telescope Assets WFIRST-AFTA 2015 Report
• Dark Energy Survey Year 3 Results: Cosmology from Cosmic Shear and Robustness to Data Calibration
• The Shear TEsting Programme 2: Factors affecting high precision weak lensing analyses
• Third Data Release of the Hyper Suprime-Cam Subaru Strategic Program
• The Intrinsic Alignment of Galaxies and its Impact on Weak Gravitational Lensing in an Era of Precision Cosmology
• The Wide Field Infrared Survey Telescope: 100 Hubbles for the 2020s
• PSF calibration requirements for dark energy from cosmic shear
• DES Y3 results: Blending shear and redshift biases in image simulations
• Metacalibration: Direct Self-Calibration of Biases in Shear Measurement
• The three-year shear catalog of the Subaru Hyper Suprime-Cam SSP Survey
• Dark Energy Survey Year 3 Results: Point-Spread Function Modeling
• Weak gravitational shear and flexion with polar shapelets
• PSF modelling for very wide-field CCD astronomy
• Validating Synthetic Galaxy Catalogs for Dark Energy Science in the LSST Era
• Fisher Matrix Stability
• Propagating residual biases in masked cosmic shear power spectra

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• A General Framework for Removing Point Spread Function Additive Systematics in Cosmological Weak Lensing Analysis
• The Vera C. Rubin Observatory Data Preview 1
• Dark Energy Survey Year 6 Results: Cell-based Coadds and Metadetection Weak Lensing Shape Catalogue
• Simulating image coaddition with the Nancy Grace Roman Space Telescope: II. Analysis of the simulated images and implications for weak lensing
• Simulating image coaddition with the Nancy Grace Roman Space Telescope: III. Software improvements and new linear algebra strategies
• The chromatic Point Spread Function of weak lensing measurement in Chinese Space Station survey Telescope