Dust Obscured Star Forming Galaxies in the Early Universe
  Motivated by recent observational constraints on dust reprocessed emission in
star forming galaxies at $z\sim 6$ and above we use the very-large cosmological
hydrodynamical simulation \bluetides\ to explore predictions for the amount of
dust obscured star formation in the early Universe ($z>8$). \bluetides\ matches
current observational constraints on both the UV luminosity function and galaxy
stellar mass function and predicts that approximately $90\%$ of the star
formation in high-mass ($M_{*}>10^{10}\,{\rm M_{\odot}}$) galaxies at $z=8$ is
already obscured by dust. The relationship between dust attenuation and stellar
mass predicted by \bluetides\ is consistent with that observed at lower
redshift. However, observations of several individual objects at $z>6$ are
discrepant with the predictions, though it is possible their uncertainties may
have been underestimated. We find that the predicted surface density of $z\ge
8$ sub-mm sources is below that accessible to current {\em Herschel}, SCUBA-2,
and ALMA sub-mm surveys. However, as ALMA continues to accrue additional
surface area the population of $z>8$ dust-obscured galaxies may become
accessible in the near future.
