The galaxy-galaxy lensing contribution to the cosmic shear two point function
Abstract
We note that galaxy-galaxy lensing by non-spherical galaxy halos produces a net anti-correlation between the shear of background galaxies and the ellipticity of foreground galaxies. This anti-correlation would contaminate the tomographic cosmic shear two point function if the effect were not taken into account. We compare the size of the galaxy-galaxy lensing contribution to the change in the cosmic shear two-point correlation function due to a change in the dark energy equation of state w of 1%. We find them comparable on scales <~5 arcmin for NFW galaxy profiles, and out to much larger scales for SIE profiles. However the galaxy-galaxy lensing signal has a characteristic spatial and redshift pattern which should allow it to be removed.
Cite
@article{arxiv.astro-ph/0608002,
title = {The galaxy-galaxy lensing contribution to the cosmic shear two point function},
author = {Sarah Bridle and Filipe B. Abdalla},
journal= {arXiv preprint arXiv:astro-ph/0608002},
year = {2009}
}
Comments
5 pages and 4 figures. Replaced to match journal version