NIFS observations of high-redshift ULIRGs (submm and radio selected): a detailed comparison of cold and hot-dust z 2 ULIRGs with hydrodynamical simulations

We propose NIFS observations to map the gas velocity and metallicity fields of a demographically complete sample of 8 high-z ULIRGs, including both submm-selected galaxies (SMGs - cold dust) and submm-faint radio galaxies (SFRGs - hot dust), at z 2. Our team includes hydrodynamical simulators from two groups who have independently identified candidate hot and cold-dust ULIRGs at high-z in their models, and we have explicitly run simulations of the expected properties observable with SINFONI. Our target ULIRGs have z's chosen to lie between sky lines, with detections already of H-alpha from our ISAAC slit observations, and where both Hapha/NII and OII/NeIII suggest a broad intrinsic spread in metallicity. The observations will allow us to address why high-redshift ULIRGs lie above the high redshift blue main-sequence of star forming galaxies (SFR versus stellar mass), and whether or not they represent the merger of two blue sequence galaxies.