Cosmic Shear from STIS Pure Parallels: Analysis

Abstract

The measurement of cosmic shear requires deep imaging with high image quality on many lines of sight to sample the statistics of large-scale structure. The expected distortion of galaxy images by cosmic shear on the STIS angular scale is a few percent, therefore the PSF anisotropy has to be understood and controlled to an accuracy better than 1%. In this poster we present the analysis of the PSF of STIS and a preliminary cosmic shear measurement using archival data from the STIS pure parallel program to show that the STIS camera on-board HST is well suited for our project. The data reduction and catalog production are described in an accompanying paper (astro-ph/0102330).

4 pages, 5 figures, to appear in the proceedings of the STScI 2001 spring symposium "The Dark Universe: Matter, Energy and Gravity" Baltimore April 2-5 2001, acknowledgements added