Talk Details

Wednesday, September 29, 2010 - 3:15pm

Zhuoyi Huang (INAF-OAC):

"Cluster weak lensing in catalog space and detection with filtering techniques."

Abstract. I will introduce the simulation program `Shuff' that I developed to simulate the weaklensing of galaxy clusters, and noises in cluster shear. It is a catalog space simulation, in which the lensing effect is applied to an input galaxy catalog and outputs a catalog of lensed galaxies. The clusters are modeled with triaxial halos at different redshift, and source galaxies are continuously distributed in redshift, with all properties of lenses and sources controlled by the user. The measurement error in galaxy shapes can be tested by producing images from Shuff output catalog, adding realistic noise as expected for real astronomical images. The cosmic shear and intrinsic alignment effects as shear noise, simulated from their power spectra, are used to construct an optimal filter for cluster detection. This filtering technique, originally suggested in Maturi et.al. 2005, is further developed with configurations of the properties of source and shear noise in specific observation, in order to optimize the limit of cluster detection with weak lensing. It is tested with the lensed galaxy catalog from Shuff simulation, and its primary application on observational images is shown.