We present a spectroscopic catalogue of 40 luminous starburst galaxies at z=0.7–1.7 ( median z=1.3 ) .
19 of these are submillimetre galaxies ( SMGs ) and 21 are submillimetre-faint radio galaxies ( SFRGs ) .
This sample helps to fill in the redshift desert at z=1.2–1.7 in previous studies as well as probing a lower luminosity population of galaxies .
Radio fluxes are used to determine star-formation rates for our sample which range from around 50 to 500 M _ { \odot } yr ^ { -1 } and are generally lower than those in z \sim 2 SMGs .
We identify nebular [ OII ] 3727 emission in the rest-UV spectra and use the linewidths to show that SMGs and SFRGs in our sample have larger linewidths and therefore dynamical masses than optically selected star-forming galaxies at similar redshifts .
The linewidths are indistinguishable from those measured in the z \sim 2 SMG populations suggesting little evolution in the dynamical masses of the galaxies between redshift 1–2 .
[ NeV ] and [ NeIII ] emission lines are identified in a subset of the spectra indicating the presence of an active galactic nucleus ( AGN ) .
In addition , a host of interstellar absorption lines corresponding to transitions of MgII and FeII ions are also detected .
These features show up prominently in composite spectra and we use these composites to demonstrate that the absorption lines are present at an average blueshift of - 240 \pm 50 kms ^ { -1 } relative to the systemic velocities of the galaxies derived from [ OII ] .
This indicates the presence of large-scale outflowing interstellar gas in these systems .
We do not find any evidence for differences in outflow velocities between SMGs and SFRGs of similar infra-red luminosities .
We find that the outflow velocities of z \sim 1.3 SMGs and SFRGs are consistent with the V \propto SFR ^ { 0.3 } local envelope seen in lower redshift Ultra-luminous Infra-red Galaxies ( ULIRGs ) .
These observations are well explained by a momentum-driven wind model .