Program: GS-2016A-Q-56

Hydrodynamical simulations of a binary supermassive black hole system show that mass accretion onto the circumbinary disk could be strongly modulated due to the binary’s orbital motion, or could be susceptible to relativistic Doppler effects, both of which would result in periodic variability in luminous quasars. Motivated by the science goal of searching for such variability signatures and to continue our approved Gemini 2015A and 2015B programs, we selected 1 more periodically variable quasar candidates in the Pan-STARRS1 (PS1) Medium Deep (MD) 04 field, which do not have archival spectra. Spectra are a critical component of our study, because they are necessary to constrain the total black hole mass of the binary candidate systems, thereby allowing us to translate orbital periods to orbital separations, and to determine the strength of their gravitational wave signal.