We present a detailed, multi-wavelength study of star formation (SF) and active galactic nucleus (AGN) activity in 11 near-infrared (IR) selected, spectroscopically confirmed massive (>~10^14^M_{sun}) galaxy clusters at 1<z~1.4 is largely consistent with field galaxies at similar epochs, indicating an era before significant quenching in the cluster cores (r<0.5Mpc). This is followed by a transition to lower SF activity as environmental quenching dominates by z~1. Enhanced SFRs are found in lower mass (10.1<logM*/M{sun}_~1, suggesting environmental triggering of AGNs during this epoch. We argue that our results --a transition from field-like to quenched SF, enhanced SF in lower mass galaxies in the cluster cores, and excess AGNs-- are consistent with a co-evolution between SF and AGNs in clusters and an increased merger rate in massive halos at high redshift.

Cone search capability for table J/ApJ/825/72/table3 (Photometry of PACS 100um detected cluster members)

Cone search capability for table J/ApJ/825/72/table1 (Cluster with deep Herschel/PACS imaging)