Volume 561, January 2014
|Number of page(s)||26|
|Section||Cosmology (including clusters of galaxies)|
|Published online||23 December 2013|
Source-lens clustering and intrinsic-alignment bias of weak-lensing estimators⋆
Institut de Physique Théorique, CEA Saclay, CNRS, URA 2306, 91191 Gif-sur-Yvette Cedex, France
Received: 26 June 2013
Accepted: 11 October 2013
Aims. We estimate the amplitude of the source-lens clustering bias and of the intrinsic-alignment bias of weak-lensing estimators of the two-point and three-point convergence and cosmic-shear correlation functions.
Methods. We use a linear galaxy bias model for the galaxy-density correlations, as well as a linear intrinsic-alignment model. 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.
Results. 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 very low-redshift galaxy (z2 ≲ 0.05) with a higher redshift galaxy (z1 ≳ 0.5), where it can reach 10% of the signal for the shear. For three-point statistics, the source-lens clustering bias is typically on the order of 10% of the signal, as soon as the three galaxy source redshifts are not identical. The intrinsic-alignment bias is typically about 10% of the signal for both two-point and three-point statistics. Thus, both source-lens clustering bias and intrinsic-alignment bias must be taken into account for three-point estimators aiming at a better than 10% accuracy.
Key words: gravitational lensing: weak / large-scale structure of Universe
Appendices are available in electronic form at http://www.aanda.org
© ESO, 2013
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