Revealing Dust Obscured Star Formation in CLJ1449+0856, a Cluster at z=2
  We present SCUBA-2 450$\mu$m and 850$\mu$m data of the mature redshift 2
cluster CLJ1449. We combine this with archival Herschel data to explore the
star forming properties of CLJ1449. Using high resolution ALMA and JVLA data we
identify potentially confused galaxies, and use the Bayesian inference tool
XID+ to estimate fluxes for them. Using archival optical and near infrared data
with the energy-balance code CIGALE we calculate star formation rates, and
stellar masses for all our cluster members, and find the star formation rate
varies between 20-1600M$_{\odot}$yr$^{-1}$ over the entire 3Mpc radial range.
The central 0.5Mpc region itself has a total star formation rate of
800$\pm$200M$_{\odot}$yr$^{-1}$, which corresponds to a star formation rate
density of (1.2$\pm$0.3)$\times$10$^{4}$M$_{\odot}$yr$^{-1}$Mpc$^{-3}$, which
is approximately five orders of magnitude greater than expected field values.
When comparing this cluster to those at lower redshifts we find that there is
an increase in star formation rate per unit volume towards the centre of the
cluster. This indicates that there is indeed a reversal in the star
formation/density relation in CLJ1449. Based on the radial star-formation rate
density profile, we see evidence for an elevation in the star formation rate
density, even out to radii of 3Mpc. At these radii the elevation could be an
order of magnitude greater than field values, but the exact number cannot be
determined due to ambiguity in the redshift associations. If this is the case
it would imply that this cluster is still accreting material which is possibly
interacting and undergoing vigorous star-formation.
