[CII] and 12CO(1-0) Emission Maps in HLSJ091828.6+514223: A Strongly
  Lensed Interacting System at z=5.24
  We present Submillimeter Array (SMA) [CII] 158um and Jansky Very Large Array
(JVLA) $^{12}$CO(1-0) line emission maps for the bright, lensed, submillimeter
source at $z=5.2430$ behind Abell 773: HLSJ091828.6+514223 (HLS0918). We
combine these measurements with previously reported line profiles, including
multiple $^{12}$CO rotational transitions, [CI], water and [NII], providing
some of the best constraints on the properties of the interstellar medium (ISM)
in a galaxy at $z>5$. HLS0918 has a total far-infrared (FIR) luminosity
L_FIR(8-1000um) = (1.6$\pm$0.1)x10^14 L_sun/mu, where the total magnification
mu_total = 8.9$\pm$1.9, via a new lens model from the [CII] and continuum maps.
Despite a HyLIRG luminosity, the FIR continuum shape resembles that of a local
LIRG. We simultaneously fit all of the observed spectral line profiles, finding
four components which correspond cleanly to discrete spatial structures
identified in the maps. The two most redshifted spectral components occupy the
nucleus of a massive galaxy, with a source plane separation <1 kpc. The reddest
dominates the continuum map (de-magnified L_FIR = (1.1$\pm$0.2)x10^13 L_sun),
and excites strong water emission in both nuclear components via a powerful FIR
radiation field from the intense star formation. A third star-forming component
is most likely a region of a merging companion (dV ~ 500 km/s) exhibiting
generally similar gas properties. The bluest component originates from a
spatially distinct region, and photo-dissociation region (PDR) analysis
suggests that it is lower density, cooler and forming stars less vigorously
than the other components. Strikingly, it has very strong [NII] emission which
may suggest an ionized, molecular outflow. This comprehensive view of gas
properties and morphology in HLS0918 previews the science possible for a large
sample of high-redshift galaxies once ALMA attains full sensitivity.
