The Infrared Properties of Super Star Clusters: Predictions from
  Three-Dimensional Radiative Transfer Models
  With high-resolution infrared data becoming available that can probe the
formation of high-mass stellar clusters for the first time, models that make
testable predictions of these objects are necessary. We utilize a
three-dimensional radiative transfer code, including a hierarchically clumped
medium, to study the earliest stages of super star cluster evolution. We
explore a range of parameter space in geometric sequences that mimic the
evolution of an embedded super star cluster. The inclusion of a hierarchically
clumped medium can make the envelope porous, in accordance with previous models
and supporting observational evidence. The infrared luminosity inferred from
observations can differ by a factor of two from the true value in the clumpiest
envelopes depending on the viewing angle. The infrared spectral energy
distribution also varies with viewing angle for clumpy envelopes, creating a
range in possible observable infrared colors and magnitudes, silicate feature
depths and dust continua. General observable features of cluster evolution
differ between envelopes that are relatively opaque or transparent to
mid-infrared photons. The [70]-[160] color can be used to determine star
formation efficiency; the Spitzer IRAC/MIPS [8.0]-[24] color is able to
constrain Rin and Rout values; and the IRAC [3.6]-[5.8] color is sensitive to
the fraction of the dust distributed in clumps. Finally, in a comparison of
these models to data of ultracompact HII regions, we find good agreement,
suggesting that these models are physically relevant, and will provide useful
diagnostic ability for datasets of resolved, embedded SSCs with the advent of
high-resolution infrared telescopes like JWST.
