2015ApJ...809..173W

We have discovered an optically rich galaxy cluster at z = 1.7089 with star formation occurring in close proximity to the central galaxy. The system, SpARCS104922.6+564032.5, was detected within the Spitzer Adaptation of the red-sequence Cluster Survey, and confirmed through Keck-MOSFIRE spectroscopy. The rest-frame optical richness of N_gal(500 kpc) = 30±8 implies a total halo mass, within 500 kpc, of ∼3.8±1.2x10¹⁴ M_☉, comparable to other clusters at or above this redshift. There is a wealth of ancillary data available, including Canada-France-Hawaii Telescope optical, UKIRT-K, Spitzer-IRAC/MIPS, and Herschel-SPIRE. This work adds submillimeter imaging with the SCUBA2 camera on the James Clerk Maxwell Telescope and near-infrared imaging with the Hubble Space Telescope. The mid/far-infrared (M/FIR) data detect an Ultra-luminous Infrared Galaxy spatially coincident with the central galaxy, with L_IR= 6.2±0.9x10¹² L_☉. The detection of polycyclic aromatic hydrocarbons at