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.

5 pages and 4 figures. Replaced to match journal version

References in corpus (1)

• Potential sources of contamination to weak lensing measurements: constraints from N-body simulations

Cited by in corpus (4)

• Dark energy constraints from cosmic shear power spectra: impact of intrinsic alignments on photometric redshift requirements
• Angular momentum-Large-scale structure alignments in LCDM models and the SDSS
• The removal of shear-ellipticity correlations from the cosmic shear signal via nulling techniques
• Cosmological Systematics Beyond Nuisance Parameters : Form Filling Functions