Forecasting the success of the WEAVE Wide-Field Cluster Survey on the extraction of the cosmic web filaments around galaxy clusters

TL;DR

This study evaluates the ability of upcoming wide-field spectroscopic surveys, specifically WWFCS, to reliably detect cosmic web filaments around galaxy clusters using simulated data and considers observational constraints.

Contribution

It demonstrates that the WWFCS can effectively extract cosmic web filaments around galaxy clusters despite observational limitations and sampling challenges.

Findings

81.7% target allocation success rate in cluster outskirts

Median filament position offset of 0.13 Mpc, smaller than filament radius

Reliable filament detection around massive clusters is feasible

Abstract

Next-generation wide-field spectroscopic surveys will observe the infall regions around large numbers of galaxy clusters with high sampling rates for the first time. Here we assess the feasibility of extracting the large-scale cosmic web around clusters using forthcoming observations, given realistic observational constraints. We use a sample of 324 hydrodynamic zoom-in simulations of massive galaxy clusters from TheThreeHundred project to create a mock-observational catalogue spanning $5R_{200}$ around 160 analogue clusters. These analogues are matched in mass to the 16 clusters targetted by the forthcoming WEAVE Wide-Field Cluster Survey (WWFCS). We consider the effects of the fibre allocation algorithm on our sampling completeness and find that we successfully allocate targets to 81.7 $\% \pm$ 1.3 of the members in the cluster outskirts. We next test the robustness of the filament extraction algorithm by using a metric, $D_{\text{skel}}$, which quantifies the distance to the filament spine. We find that the median positional offset between reference and recovered filament networks is $D_{\text{skel}} = 0.13 \pm 0.02$ Mpc, much smaller than the typical filament radius of $\sim$ 1 Mpc. Cluster connectivity of the recovered network is not substantially affected. Our findings give confidence that the WWFCS will be able to reliably trace cosmic web filaments in the vicinity around massive clusters, forming the basis of environmental studies into the effects of pre-processing on galaxy evolution.