Pixel Noise Effect and its Correction method by ERA Method for Precise Weak Gravitational Lensing Shear Measurement

Abstract

Highly precise weak lensing shear measurement is required for statistical weak gravitational lensing analysis such as cosmic shear measurement to achieve severe constrain on the cosmological parameters. For this purpose any systematic error in the measurement should be corrected. One of the main systematic error comes from Pixel noise which is Poisson noise of flux from atmosphere. We investigate how the pixel noise makes systematic error in shear measurement based on ERA method and develop the correction method. This method is tested by simulations with various conditions and it is confirmed that the correction method can correct $80 \sim 90\%$ of the systematic error except very low signal to noise ratio galaxies.