Probing Satellite Halos with Weak Gravitational Lensing

TL;DR

This paper explores the potential of using weak gravitational lensing to detect tidal stripping of dark matter subhalos in galaxy groups through simulations, forecasting observable signals and methodological approaches.

Contribution

It introduces simulation-based forecasts for detecting dark matter stripping in galaxy groups using weak lensing, addressing challenges in identifying group centers.

Findings

Detection of stripping possible in groups with mass 10^12--10^15 Msun.

Mock catalogues demonstrate the lensing signals around satellites.

Two methods tested for isolating satellite lensing signals.

Abstract

We demonstrate the possibility of detecting tidal stripping of dark matter subhalos within galaxy groups using weak gravitational lensing. We have run ray-tracing simulations on galaxy catalogues from the Millennium Simulation to generate mock shape catalogues. The ray-tracing catalogues assume a halo model for galaxies and groups, using various models with different distributions of mass between galaxy and group halos to simulate different stages of group evolution. Using these mock catalogues, we forecast the lensing signals that will be detected around galaxy groups and satellite galaxies, as well as test two different methods for isolating the satellites' lensing signals. A key challenge is to determine the accuracy to which group centres can be identified. We show that with current and ongoing surveys, it will possible to detect stripping in groups of mass 10^12--10^15 Msun.