Shear Measurement with Poorly Resolved Images

Abstract

Weak lensing studies typically require excellent seeing conditions for the purpose of maximizing the number density of well-resolved galaxy images. It is interesting to ask to what extent the seeing size limits the usefulness of the astronomical images in weak lensing. In this work, we study this issue with the data of the DECam Legacy Survey (DECaLS), which is a part of the target selection program for the Dark Energy Spectroscopic Instrument (DESI). Using the Fourier Quad shear measurement pipeline, we demonstrate that images with relatively poor seeing conditions (around 1.5 arcsec) can still yield accurate shear estimators. We do not find any correlation between systematic shear error and the image resolution.

13 pages, 19 figures, submitted

References in corpus (6)

• Dark Energy Survey Year 3 Results: Cosmological Constraints from Galaxy Clustering and Weak Lensing
• Dark Energy Survey Year 3 Results: Cosmology from Cosmic Shear and Robustness to Data Calibration
• A discriminating probe of gravity at cosmological scales
• Constraining $f(R)$ Gravity Theory Using Weak Lensing Peak Statistics from the Canada-France-Hawaii-Telescope Lensing Survey
• Dark Energy Survey Year 3 Results: Point-Spread Function Modeling
• Characterization and correction of charge-induced pixel shifts in DECam

Cited by in corpus (6)

• DESI Legacy Imaging Surveys Data Release 9: Cosmological Constraints from Galaxy Clustering and Weak Lensing using the Minimal Bias Model
• Dark against luminous matter around isolated central galaxies: a comparative study between modern surveys and Illustris-TNG
• Tele-Correlation: Calibrating Shear-Shear Correlation with Real Data
• Quasi-2D Weak Lensing Cosmological Constraints Using the PDF-SYM method
• Satellite Content and Halo Mass of Galaxy Clusters: Comparison between Red-Sequence and Halo-based Optical Cluster Finders
• Ellipticities of Galaxy Cluster Halos from Halo-Shear-Shear Correlations