Comparison of hydrostatic and lensing cluster mass estimates: A pilot study in MACS J0647.7+7015

The detailed characterization of scaling laws relating the observables of a cluster of galaxies to their mass is crucial for obtaining accurate cosmological constraints with clusters. In this paper, we present a comparison between the hydrostatic and lensing mass profiles of the cluster MACS J0647.7+7015 at z'='0.59. The hydrostatic mass profile is obtained from the combination of high resolution NIKA2 thermal Sunyaev-Zel'dovich and XMM-Newton X-ray observations of the cluster. The lensing mass profile, on the other hand, is obtained from an analysis of the CLASH lensing data based on the lensing convergence map. We find significant variation in the cluster mass estimate depending on the observable, the modeling of the data, and the knowledge of the cluster's dynamical state. This might lead to significant systematic effects on cluster cosmological analyses for which only a single observable is generally used. From this pilot study, we conclude that the combination of high resolution Sunyaev-Zel'dovich, X-ray, and lensing data could allow us to identify and correct for these systematic effects. This would constitute a very interesting extension of the NIKA2 SZ Large Program.