• Finner, Kyle
;
• Jee, M. James
;
• Golovich, Nathan
;
• Wittman, David
;
• Dawson, William
;
• Gruen, Daniel
;
• Koekemoer, Anton M.
;
• Lemaux, Brian C.
;
• Seitz, Stella

Abstract

The second most significant detection of the Planck Sunyaev-Zel’dovich survey, PLCK G287.0+32.9 (z = 0.385), boasts two similarly bright radio relics and a radio halo. One radio relic is located ∼ 400 {kpc} NW of the X-ray peak and the other ∼ 2.8 Mpc to the SE. This large difference suggests that a complex merging scenario is required. A key missing puzzle for the merging scenario reconstruction is the underlying dark matter distribution in high resolution. We present a joint Subaru Telescope and Hubble Space Telescope weak-lensing analysis of the cluster. Our analysis shows that the mass distribution features four significant substructures. Of the substructures, a primary cluster of mass {M}_200{{c}}={1.59}_-0.22^+0.25×ばつ {10}¹⁵ {h}₇₀^-1 {M}_☉ dominates the weak-lensing signal. This cluster is likely to be undergoing a merger with one (or more) subcluster whose mass is approximately a factor of 10 lower. One candidate is the subcluster of mass {M}_200{{c}}={1.16}_-0.13^+0.15×ばつ {10}¹⁴ {h}₇₀^-1 {M}_☉ located ∼ 400 {kpc} to the SE. The location of this subcluster suggests that its interaction with the primary cluster could be the source of the NW radio relic. Another subcluster is detected ∼ 2 Mpc to the SE of the X-ray peak with mass {M}_200{{c}}={1.68}_-0.20^+0.22×ばつ {10}¹⁴ {h}₇₀^-1 {M}_☉ . This SE subcluster is in the vicinity of the SE radio relic and may have created the SE radio relic during a past merger with the primary cluster. The fourth subcluster, {M}_200{{c}}={1.87}_-0.22^+0.24×ばつ {10}¹⁴ {h}₇₀^-1 {M}_☉ , is NW of the X-ray peak and beyond the NW radio relic.