A Multi-wavelength Mass Analysis of RCS2 J232727.6-020437, A ~3 × 10^(15) M_⊙ Galaxy Cluster at z = 0.7

We present an initial study of the mass and evolutionary state of a massive and distant cluster, RCS2 J232727.6-020437. This cluster, at z = 0.6986, is the richest cluster discovered in the RCS2 project. The mass measurements presented in this paper are derived from all possible mass proxies: X-ray measurements, weak-lensing shear, strong lensing, Sunyaev–Zel'dovich effect decrement, the velocity distribution of cluster member galaxies, and galaxy richness. While each of these observables probe the mass of the cluster at a different radius, they all indicate that RCS2 J232727.6−020437 is among the most massive clusters at this redshift, with an estimated mass of M_(200) ~ 3 x 10^(15)h_(70)^(-1) M_☉. In this paper, we demonstrate that the various observables are all reasonably consistent with each other to within their uncertainties. RCS2 J232727.6−020437 appears to be well relaxed—with circular and concentric X-ray isophotes, with a cool core, and no indication of significant substructure in extensive galaxy velocity data.