Characterizing the WISE-selected heavily obscured quasar population with optical spectroscopy from the Southern African Large Telescope

James O. Freedman Presidential Scholars Program; Dartmouth E.E. Just Program; National Science Foundation [1515364]; Faculty Early Career Development Program [1554584]; National Aeronautics and Space Administration [NNX16AN48G, NNX15AP24G]; National Aeronautics and Space Administration; Alfred P. Sloan Foundation; National Science Foundation; U.S. Department of Energy Office of Science