1306.6151 (Patrick Valageas)

Source-lens clustering bias of weak-lensing estimators    [PDF]

Patrick Valageas

We estimate the amplitude of the source-lens clustering bias of weak lensing estimators of the two-point and three-point convergence and cosmic shear correlation functions. We use a linear galaxy bias model for the galaxy-density correlations. For the three-point and four-point density correlations we use analytical or semi-analytical models, based on a hierarchical ansatz or a combination of one-loop perturbation theory with a halo model. For two-point statistics, we find that the source-lens clustering bias is typically several orders of magnitude below the weak lensing signal, except when we correlate a low-redshift galaxy ($z_2 \la 0.05$) with a higher redshift galaxy ($z_1 \ga 0.5$), where it can reach 10% of the signal for the shear. For three-point statistics, the source-lens clustering bias is typically of order 10% of the signal, as soon as the three galaxy source redshifts are not identical.

View original: http://arxiv.org/abs/1306.6151