Princeton graduate student Wendy Ju has searched through repeat observations of SDSS quasars looking for radial velocity shifts indicating sub-pc--scale black hole binaries. We have seven candidates that Princeton undergraduate Eric Bolton is following up now...
Do supermassive black holes stall at ~1 pc? Or do they merge in a Hubble time? We are searching for sub-pc binaries in the SDSS to try and answer this question empirically at z~1-2, the peak of quasar activity.
BLACK HOLE BINARIES