PSF Anisotropy and Systematic Errors in Weak Lensing Surveys

Abstract

Given the basic parameters of a cosmic shear weak lensing survey, how well can systematic errors due to anisotropy in the point spread function (PSF) be corrected? The largest source of error in this correction to date has been the interpolation of the PSF to the locations of the galaxies. To address this error, we separate the PSF patterns into components that recur in multiple exposures/pointings and those that vary randomly between different exposures (such as those due to the atmosphere). In an earlier study we developed a principal component approach to correct the recurring PSF patterns (Jarvis and Jain 2004). In this paper we show how randomly varying PSF patterns can also be circumvented in the measurement of shear correlations. For the two-point correlation function this is done by simply using pairs of galaxy shapes measured in different exposures. Combining the two techniques allows us to tackle generic combinations of PSF anisotropy patterns. The second goal of this paper is to give a formalism for quantifying residual systematic errors due to PSF patterns. We show how the main PSF corrections improve with increasing survey area (and thus can stay below the reduced statistical errors), and we identify the residual errors which do not scale with survey area. Our formalism can be applied both to planned lensing surveys to optimize instrumental and survey parameters and to actual lensing data to quantify residual errors.

arXiv comment18 pages, 1 figure; revised submission with minor edits

References in corpus (24)

• Stable clustering, the halo model and nonlinear cosmological power spectra
• A Method for Weak Lensing Observations
• Shapes and Shears, Stars and Smears: Optimal Measurements for Weak Lensing
• A new measure for cosmic shear
• Shear calibration biases in weak lensing surveys
• Cosmological parameters from lensing power spectrum and bispectrum tomography
• Systematic errors in weak lensing: application to SDSS galaxy-galaxy weak lensing
• Spin induced galaxy alignments and their implications for weak lensing measurements
• B-modes in cosmic shear from source redshift clustering
• Shapelets: II. A Method for Weak Lensing Measurements
• A New Shear Estimator for Weak Lensing Observations
• Baryons and weak lensing power spectra
• Effect of Hot Baryons on the Weak-Lensing Shear Power Spectrum
• Statistics of Dark Matter Halos from Gravitational Lensing
• The effect of imperfect corrections of PSF anisotropy on cosmic shear measurements
• Halo properties in models with dynamical Dark Energy
• Searching for dark matter halos in the Suprime-Cam 2 sq deg field
• Reducing the shear
• A New Strategy for Deep Wide-Field High Resolution Optical Imaging
• Implication of Omega_m through the Morphological Analysis of Weak Lensing Fields
• Large scale systematic signals in weak lensing surveys
• The Topology of Weak Lensing Fields
• Inhomogeneous systematic signals in cosmic shear observations
• The topology of weak lensing field in the neighborhood of MS1054-03

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• Origins of weak lensing systematics, and requirements on future instrumentation (or knowledge of instrumentation)
• PSF calibration requirements for dark energy from cosmic shear
• Catastrophic photometric redshift errors: weak lensing survey requirements
• Interpolating point spread function anisotropy
• Shears from shapelets
• Scientific Synergy Between LSST and Euclid
• Distance, Growth Factor, and Dark Energy Constraints from Photometric Baryon Acoustic Oscillation and Weak Lensing Measurements
• Shear Recovery Accuracy in Weak Lensing Analysis with Elliptical Gauss-Laguerre Method
• Cosmic tomographies: baryon acoustic oscillations and weak lensing
• Image Analysis for Cosmology: Results from the GREAT10 Star Challenge
• Cosmological Constraint Precision of the Photometric and Spectroscopic Multi-probe Surveys of China Space Station Telescope (CSST)
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• Spurious Shear in Weak Lensing with LSST
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• Forecast of Neutrino Cosmology from the CSST Photometric Galaxy Clustering and Cosmic Shear Surveys
• Sources of contamination to weak lensing tomography: redshift-dependent shear measurement bias
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• Diagnosing space telescope misalignment and jitter using stellar images
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