Cluster mass profile reconstruction with size and flux magnification on
  the HST STAGES survey
  We present the first measurement of individual cluster mass estimates using
weak lensing size and flux magnification. Using data from the HST-STAGES survey
of the A901/902 supercluster we detect the four known groups in the
supercluster at high significance using magnification alone. We discuss the
application of a fully Bayesian inference analysis, and investigate a broad
range of potential systematics in the application of the method. We compare our
results to a previous weak lensing shear analysis of the same field finding the
recovered signal-to-noise of our magnification-only analysis to range from 45%
to 110% of the signal-to-noise in the shear-only analysis. On a case-by-case
basis we find consistent magnification and shear constraints on cluster virial
radius, and finding that for the full sample, magnification constraints to be a
factor $0.77 \pm 0.18$ lower than the shear measurements.
