2014MNRAS.441.1601P

Recent simulations of the densest portion of the Corona Borealis supercluster (A2061, A2065, A2067, and A2089) have shown virtually no possibility of extended gravitationally bound structure without inter-cluster matter. In contrast, recent analyses of the dynamics found that the clusters had significant peculiar velocities towards the supercluster centroid. In this paper we present the results of a thorough investigation of the CSC: we determine redshifts and virial masses for all eight clusters associated with the CSC; repeat the analysis of Batiste & Batuski with the inclusion of A2056 and CL1529+29; estimate the mass of the supercluster by applying the virial theorem on the supercluster scale, the caustics method, and a new procedure using the spherical collapse model (SCM) with the results of the dynamical analysis (SCM+FP); and perform a series of simulations to assess the likelihood of the CSC being a gravitationally bound supercluster. We find that the mass of the CSC is between 0.6 and 12x10¹⁶h-1M_☉. The dynamical analysis, caustics method and the SCM+FP indicate that the structure is collapsing, with the latter two both indicating a turn around radius of ∼ 12.5h-1Mpc. Lastly, the simulations show that with a reasonable amount of inter-cluster mass, there is likely extended bound structure in the CSC. Our results suggest that A2056, A2061, A2065, A2067, and A2089 form a gravitationally bound supercluster.