2016ApJ...817...24M

We present a weak-lensing analysis of the merging Frontier Fields (FF) cluster Abell 2744 using new Subaru/Suprime-Cam imaging. The wide-field lensing mass distribution reveals this cluster is comprised of four distinct substructures. Simultaneously modeling the two-dimensional reduced shear field using a combination of a Navarro-Frenk-White (NFW) model for the main core and truncated NFW models for the subhalos, we determine their masses and locations. The total mass of the system is constrained as M_200c = (2.06 ± 0.42) x 10¹⁵M_☉ The most massive clump is the southern component with M_200c = (7.7 ± 3.4) x 10¹⁴ M_☉ followed by the western substructure (M_200c = (4.5 ± 2.0) x 10¹⁴M_☉) and two smaller substructures to the northeast ( M_200c = (2.8 +/1.6) x 10¹⁴ M_☉) and northwest ( M_200c = (1.9 +/1.2) x 10¹⁴ M_☉). The presence of the four substructures supports the picture of multiple mergers. Using a composite of hydrodynamical binary simulations we explain this complicated system without the need for a ''slingshot'' effect to produce the northwest X-ray interloper, as previously proposed. The locations of the substructures appear to be offset from both the gas (87_–28⁺³⁴ arcsec, 90% CL) and the galaxies (72₅₃⁺³⁴ arcsec, 90% CL) in the case of the northwestern and western subhalos. To confirm or refute these findings, high resolution space-based observations extending beyond the current FF limited coverage to the west and northwestern area are essential.