Special Seminar

Speaker: Chihway Chang (Stanford)
Title: Drawing Photons from the Future -- the LSST Photon Simulator and Shear Systematics Studies
Date (JST): Tue, Jul 31, 2012, 14:00 - 15:00
Place: Seminar Room B
Abstract: The Large Synoptic Survey Telescope (LSST) is one of the most ambitious ground based weak lensing survey telescope in the upcoming decade. To take full advantage of the unprecedented statistical power of LSST survey, systematic errors in shear measurements need to be controlled to exquisite levels. In order to quantitatively understand these systematics, we are investigating a series of issues associated with weak lensing measurements by invoking the LSST Photon Simulator -- a high-fidelity Monte Carlo photon raytracing code that captures all the major physical effects in the system from the top of the atmosphere down through the detectors.
In this talk I will present some results from these studies including quantifying the impact on shear measurement from different physical effects in the system, understanding the characteristics of the Point Spread Function (PSF) for LSST, estimating the additive spurious shear in cosmic shear measurements and developing new algorithms for weak lensing measurements that are optimized for the expected data from LSST.