  We present the results of a panoramic (15 Mpc-scale) survey of the Cl0016+16
supercluster (z=0.55) using Spitzer Space Telescope MIPS 24um and Galaxy
Evolution Explorer near-UV (2500A; NUV) imaging. The supercluster regions
probed are characterised by several dense nodes connected by a pronounced
intermediate-density filamentary structure. We have studied the mid-IR and NUV
properties of potential cluster members within a Dz=0.1 photometric redshift
slice, compared to an identical blank field selection. We have two main
findings: (a) the star-formation rates of individual star-forming galaxies
throughout the cluster are not significantly different to identically selected
field galaxies, and (b) the cluster harbours pockets of 'accelerated' activity
where galaxies have an enhanced probability of undergoing star formation. This
observation could be explained in a simple model of 'pre-processing' of
galaxies during cluster infall: galaxies in satellite groups have an increased
chance of having star-formation triggered via gravitational tidal interactions
compared to their counterparts in the field, but there is no environmental
mechanism boosting the individual star-formation rates of galaxies. We estimate
a lower-limit for the total star-formation rate of galaxies in the supercluster
as ~850 Msun/yr (field corrected). If this rate is maintained over the typical
infall time of a few Gyr, then the infall population could contribute
~1-2x10^12 Msun of stellar mass to the structure.
