Program: GN-2021A-Q-121

We propose to use Gemini/GMOS-N to spectroscopically confirm the nature of a statistical sample of dual quasar candidates having a projected separation between 7-20 kpc, a rare population. With the Hyper Suprime-Cam (HSC) Subaru Strategic Program, we have identified a population of SDSS quasars as having two components with flux ratios within a factor of 10:1. GMOS-N in queue mode is needed to acquire spectra of each component for those with projected separations between 1-3.5". With a final sample of 20 spectroscopically-confirmed close dual quasars, we will measure their frequency and evolution of such systems up to z~4 with a comparison to predictions from recent hydrodynamic cosmological simulations. These results will place important constraints on merger simulations of galaxies and their supermassive black holes that are input to an estimate of gravitational wave events to be detected by LISA. Furthermore, there is great scientific potential to develop this technique to find dual SMBHs with statistical samples given future wide-area imaging with LSST, Euclid and WFIRST.