Probing dark matter caustics with weak lensing

¹ Laboratoire d'Astrophysique, UMR 5572 CNRS & Université Paul Sabatier, 14 Av. Edouard Belin, 31400 Toulouse, France e-mail: rgavazzi@ast.obs-mip.fr
² Oxford University, Astrophysics, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH, UK
³ Institut d'Astrophysique de Paris, UMR 7095 CNRS & Université Pierre & Marie Curie, 98bis Bd. Arago, 75014 Paris, France

Abstract

We correct two errors that were present in the former version of this paper. First, a factor  was missing in the expression of the smooth density profile of the dark matter halo (Eq. (1)) that propagates into the expression of the projected smooth density profile (Eq. (9)). Second, the numerical integration of the caustics' density profile also misses a factor of 2, although the equations are correct. The former error has no effect on the analysis but the latter makes the weak lensing signal twice stronger than previously published. Therefore, the detection of dark matter caustics through weak lensing is made easier. Instead of a superposition of about 200 cluster-size halos, one would require only ∼100 such systems for the caustics to show up in ground-based observations. Similarly, space-based weak lensing data would achieve the same detection threshold with ∼30 galaxy clusters.