Measuring the mass distribution of voids with stacked weak lensing

Abstract

We study the prospects for measuring the dark matter distribution of voids with stacked weak lensing. We select voids from a large set of N-body simulations and explore their lensing signals with the full ray-tracing simulations including the effect of the large-scale structure along the line of sight. The lensing signals are compared with simple void model predictionsto infer the three-dimensional mass distribution of voids.We show that the stacked weak lensing signals are detected at a significant level (S/N ≥ 5) for a 5000 degree2 survey area, for a wide range of void radii up to ~50 Mpc. The error from the galaxy shape noise little affects lensing signals at large scale. It is also found that dense ridges around voids have a great impact onthe weak lensing signals, suggesting that proper modelling of the void density profile including surrounding ridges is essential for extracting the average total underdense mass of voids. © 2013 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society.