Astrophysics Luncheon Seminar Quasars with Periodic Variability as Sub-parsec Supermassive Black Hole Binary Candidates Presented by Maria Charisi California Institute of Technology Monday, March 19, 2018 12:00 noon in 169-336 and on Webex Abstract Supermassive Black Hole Binaries (SMBHBs) are expected to form frequently in galactic nuclei as a result of galaxy mergers. However, the observational evidence for such systems, especially for binaries at sub-parsec separations, remains sparse. Hydrodynamical simulations predict that SMBHBs produce quasar-like luminosities, with variability periodically modulated at the orbital period of the binary. I will present a systematic search for quasars with periodic variability in the Palomar Transient Factory and the detection of a population of candidate SMBHBs. Moreover, I will also discuss follow-up work to uncover additional evidence for the binary nature of the identified candidates, such as relativistic Doppler boost. JPL Contact: Joe Lazio (4-4198)   Site Manager: Webmaster: CL 08-3220