NOEMA Redshift Measurements of Extremely Bright Submillimeter Galaxies
  Near the GOODS-N
  We report spectroscopic redshift measurements for three bright submillimeter
galaxies (SMGs) near the GOODS-N field, each with SCUBA-2 850 micron fluxes >
10 mJy, using the Northern Extended Millimeter Array (NOEMA). Our molecular
linescan observations of these sources, which occupy a ~7 arcmin$^2$ area
outside of the HST coverage of the field, reveal that two lie at $z \sim$ 3.14.
In the remaining object, we detect line emission consistent with CO(7-6), [C
I], and H2O at $z$ = 4.42. The far-infrared spectral energy distributions of
these galaxies, constrained by SCUBA-2, NOEMA, and Herschel/SPIRE, indicate
instantaneous SFRs $\sim4000 ~{\rm M_{\odot}~yr^{-1}}$ in the $z$ = 4.42 galaxy
and $\sim 2500~{\rm M_{\odot}~yr^{-1}}$ in the two $z \sim$ 3.14 galaxies.
Based on our sources' CO line luminosities, we estimate $M_{{\rm
gas}}\sim10^{11} M_{\odot}$ and find gas depletion timescales of $\tau_{{\rm
depl}}\sim 50$ Myr, consistent with findings in other high-redshift SMGs.
Finally, we show that the two $z \sim$ 3.14 sources, which alone occupy a
volume $\sim$10 Mpc$^3$, very likely mark the location of a protocluster of
bright SMGs and less dusty optical sources.
