Selection and Mid-infrared Spectroscopy of Ultraluminous Star-Forming
  Galaxies at z~2
  Starting from a sample of 24 \micron\ sources in the Extended Groth Strip, we
use 3.6 to 8 \micron\ color criteria to select ultraluminous infrared galaxies
(ULIRGs) at $z\sim2$. Spectroscopy from 20-38 \micron\ of 14 objects verifies
their nature and gives their redshifts. Multi-wavelength data for these objects
imply stellar masses ${>}10^{11}$ \Msun\ and star formation rates $\ge$410
\Msun yr$^{-1}$. Four objects of this sample observed at 1.6 \micron\
(rest-frame visible) with {\it HST}/WFC3 show diverse morphologies, suggesting
that multiple formation processes create ULIRGs. Four of the 14 objects show
signs of active galactic nuclei, but the luminosity appears to be dominated by
star formation in all cases.
