Metadetection Weak Lensing for the Vera C. Rubin Observatory

Abstract

Forthcoming astronomical imaging surveys will use weak gravitational lensing shear as a primary probe to study dark energy, with accuracy requirements at the 0.1% level. We present an implementation of the Metadetection shear measurement algorithm for use with the Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST). This new code works with the data products produced by the LSST Science Pipelines, and uses the pipeline algorithms when possible. We tested the code using a new set of simulations designed to mimic LSST imaging data. The simulated images contained semi-realistic galaxies, stars with representative distributions of magnitudes and galactic spatial density, cosmic rays, bad CCD columns and spatially variable point spread functions. Bright stars were saturated and simulated ``bleed trails'' were drawn. Problem areas were interpolated, and the images were coadded into small cells, excluding images not fully covering the cell to guarantee a continuous point spread function. In all our tests the measured shear was accurate within the LSST requirements.

arXiv comment10 pages, 5 figures; minor text updates and additional references

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Cited by in corpus (8)

• Simulating image coaddition with the Nancy Grace Roman Space Telescope: I. Simulation methodology and general results
• A Differentiable Perturbation-based Weak Lensing Shear Estimator
• Dark Energy Survey Year 6 Results: Cell-based Coadds and Metadetection Weak Lensing Shape Catalogue
• Analytical Noise Bias Correction for Precise Weak Lensing Shear Inference
• Intrinsic alignment from multiple shear estimates: A first application to data and forecasts for Stage IV
• Weak Gravitational Lensing
• Spot-Based Measurement of the Brighter-Fatter Effect on a Roman Space Telescope H4RG Detector and Comparison with Flat-Field Data
• D${}_4$CNN$\times$AnaCal: Physics-Informed Machine Learning for Accurate and Precise Weak Lensing Shear Estimation