Toward understanding the anisotropic point spread function of Suprime-Cam and its impact on cosmic shear measurement

Understand

We examined the anisotropic point spread function (PSF) of Suprime-Cam data utilizing dense star field data.

• We decomposed the PSF ellipticities into three components, the optical aberration, atmospheric turbulence, and chip-misalignment in an empirical manner, and evaluated the amplitude of each component.
• We found that, for long-exposure data, the optical aberration has the largest contribution to the PSF ellipticities, which could be modeled well by a simple analytic function based on the lowest-order aberration theory.
• The statistical properties of PSF ellipticities resulting from the atmospheric turbulence were investigated by using the numerical simulations.