Noiseless Gravitational Lensing Simulations

Abstract

The microphysical properties of the DM particle can, in principle, be constrained by the properties and abundance of substructures in DM halos, as measured through strong gravitational lensing. Unfortunately, there is a lack of accurate theoretical predictions for the lensing signal of substructures, mainly because of the discreteness noise inherent to N-body simulations. Here we present Recursive-TCM, a method that is able to provide lensing predictions with an arbitrarily low discreteness noise, without any free parameters or smoothing scale. This solution is based on a novel way of interpreting the results of N-body simulations, where particles simply trace the evolution and distortion of Lagrangian phase-space volume elements. We discuss the advantages of this method over the widely used cloud-in-cells and adaptive-kernel smoothing density estimators. Applying the new method to a cluster-sized DM halo simulated in warm and cold DM scenarios, we show how the expected differences in their substructure population translate into differences in the convergence and magnification maps. We anticipate that our method will provide the high-precision theoretical predictions required to interpret and fully exploit strong gravitational lensing observations.

13 pages, 13 figures. Updated fig 12, references added

References in corpus (6)

• Environmental Dependence of Cold Dark Matter Halo Formation
• The assembly bias of dark matter haloes to higher orders
• Arc sensitivity to cluster ellipticity, asymmetries and substructures
• Substructure in lensing clusters and simulations
• Measuring primordial non-Gaussianity with weak-lensing surveys
• Smooth Particle Lensing

Cited by in corpus (14)

• Cosmology with cosmic shear observations: a review
• An adaptively refined phase-space element method for cosmological simulations and collisionless dynamics
• Earth-mass haloes and the emergence of NFW density profiles
• An exact general remeshing scheme applied to physically conservative voxelization
• The Persistent Percolation of Single-Stream Voids
• Voids in cosmological simulations over cosmic time
• The lensing properties of subhaloes in massive elliptical galaxies in sterile neutrino cosmologies
• Extending the halo mass resolution of $N$-body simulations
• Topology and geometry of the dark matter web: a multistream view
• Characterising Strong Lensing Galaxy Clusters using the Millennium-XXL and MOKA simulations
• Non-Halo Structures and their Effects on Gravitational Lensing
• Structure in the 3D Galaxy Distribution: II. Voids and Watersheds of Local Maxima and Minima
• Massively Parallel Computation of Accurate Densities for N-body Dark Matter Simulations using the Phase-Space-Element Method
• Collisionless Dynamics and the Cosmic Web