Core Mass Estimates in Strong Lensing Galaxy Clusters: a Comparison Between Masses Obtained from Detailed Lens Models, Single-Halo Lens Models, and Einstein Radii

Abstract

The core mass of galaxy clusters is both an important anchor of the radial mass distribution profile and probe of structure formation. With thousands of strong lensing galaxy clusters being discovered by current and upcoming surveys, timely, efficient, and accurate core mass estimates are needed. We assess the results of two efficient methods to estimate the core mass of strong lensing clusters: the mass enclosed by the Einstein radius ($M_{corr}(<θ_E)$ where $θ_{\rm E}$ is approximated from arc positions; Remolina González et al. 2020), and single-halo lens model ($M_{\rm{SHM}}(<\rm{e}θ_{\rm{E}})$; Remolina González et al. 2021), against measurements from publicly available detailed lens models ($M_{\rm{DLM}}$) of the same clusters. We use data from the Sloan Giant Arc Survey, the Reionization Lensing Cluster Survey, the \Hubble\ Frontier Fields, and the Cluster Lensing and Supernova Survey with \Hubble. We find a scatter of $18.3\%$ ($8.4\%$) with a bias of $-7.5\%$ ($0.4\%$) between $M_{corr}(<θ_E)$ ($M_{\rm{SHM}}(<\rm{e}θ_{\rm{E}})$) and $M_{\rm{DLM}}$. Last, we compare the statistical uncertainties measured in this work to those from simulations. This work demonstrates the successful application of these methods to observational data. As the effort to efficiently model the mass distribution of strong lensing galaxy clusters continues, we need fast, reliable methods to advance the field.