https://hal-cea.archives-ouvertes.fr/cea-01162321Valageas, PatrickPatrickValageasIPHT - Institut de Physique Théorique - UMR CNRS 3681 - CEA - Commissariat à l'énergie atomique et aux énergies alternatives - Université Paris-Saclay - CNRS - Centre National de la Recherche ScientifiqueSource-lens clustering and intrinsic-alignment bias of weak-lensing estimatorsHAL CCSD2014gravitational lensing: weaklarge-scale structure of Universe[PHYS.ASTR] Physics [physics]/Astrophysics [astro-ph]Sciences, EDP2015-06-10 11:06:022023-02-09 04:53:222015-06-12 10:47:16enJournal articleshttps://hal-cea.archives-ouvertes.fr/cea-01162321/document10.1051/0004-6361/201322146application/pdf1Aims. 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.