The Galaxy-galaxy Lensing Contribution to the Cosmic Shear Two Point Function
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چکیده
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 cosmological weak lensing 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 5%. We find them comparable on scales ∼< 10 . However the galaxy-galaxy lensing signal has a characteristic spatial and redshift pattern which should allow it to be removed. Subject headings: cosmology – gravitational lensing, large-scale structure of the universe
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تاریخ انتشار 2006