Measuring the mass distribution of voids with stacked weak lensing

TL;DR

This paper investigates the potential of stacked weak lensing to measure the dark matter distribution of cosmic voids, demonstrating significant detection prospects and emphasizing the importance of modeling surrounding ridges.

Contribution

It provides a detailed analysis of weak lensing signals around voids using simulations, highlighting the impact of void ridges and the feasibility for large-area surveys.

Findings

Weak lensing signals detectable at S/N ≥ 5 for 5000 deg² surveys.

Galaxy shape noise minimally affects large-scale lensing measurements.

Ridges around voids significantly influence the lensing signals.

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 predictions to infer the three-dimensional mass distribution of voids. We show that the stacked weak lensing signals are detected at significant level (S/N$\geq5$) for a 5000 degree$^2$ survey area, for a wide range of void radii up to $\sim50$ 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 on the weak lensing signals, suggesting that proper modeling of the void density profile including surrounding ridges is essential for extracting the average total underdens mass of voids.