Shear Recovery Accuracy in Weak-Lensing Analysis with the Elliptical Gauss-Laguerre Method

We implement the Elliptical Gauss-Laguerre (EGL) galaxy-shape measurementmethod proposed by Bernstein & Jarvis (2002) and quantify the shear recoveryaccuracy in weak lensing analysis. This method uses a deconvolution fittingscheme to remove the effects of the point-spread function (PSF). The testsimulates >10^7 noisy galaxy images convolved with anisotropic PSFs, andattempts to recover an input shear. The tests are designed to be immune toshape noise, selection biases, and crowding. The systematic error in shearrecovery is divided into two classes, calibration (multiplicative) andadditive, with the latter arising from PSF anisotropy. At S/N > 50, thedeconvolution method measures the galaxy shape and input shear to ~ 1%multiplicative accuracy, and suppresses > 99% of the PSF anisotropy. Thesesystematic errors increase to ~ 4% for the worst conditions, with poorlyresolved galaxies at S/N ~ 20. The EGL weak lensing analysis has the bestdemonstrated accuracy to date, sufficient for the next generation of weaklensing surveys.Comment: 22 pages, 14 figures, submitted to Astronomical Journa