Three Dusty Star Forming Galaxies at $z\sim1.5$: Mergers and Disks on
  the Main Sequence
  The main sequence of galaxies, a correlation between the star formation rates
and stellar masses of galaxies, has been observed out to $z\sim4$. Galaxies
within the scatter of the correlation are typically interpreted to be secularly
evolving while galaxies with star formation rates elevated above the main
sequence are interpreted to be undergoing interactions or to be Toomre-unstable
disks with starbursting clumps. In this paper we investigate the recent merger
histories of three dusty star forming galaxies, identified by their bright
submillimeter emission at $z\sim1.5$. We analyze rest-frame optical and UV
imaging, rest-frame optical emission line kinematics using slit spectra
obtained with MOSFIRE on Keck I, and calculate Gini and M$_{20}$ statistics for
each galaxy and conclude two are merger-driven while the third is an isolated
disk galaxy. The disk galaxy lies $\sim$4$\times$ above the main sequence, one
merger lies within the scatter of the main sequence, and one merger lies
$\sim$4$\times$ below the main sequence. This hints that the location of a
galaxy with respect to the main sequence may not be a useful discriminator of
the recent star formation history of high-M$_{\star}$ galaxies at $z\sim1$.
