Program: GN-2010A-Q-103

We propose to use GMOS-N to obtain longslit spectra of three quasars, SDSS J0927+2943, J1050+3456 and E1821+643 which have recently been identified as candidates for gravitational recoil of a supermassive black hole (SMBH), following the coalescence of a progenitor binary SMBH. We will use the data to make spectroastrometric measurements that will allow us to study the spatial structure of the nuclear emission line regions on scales <10 mas, corresponding to linear scales ~10 pc. Measurements of the relative positions of the broad and narrow line velocity systems will provide important insights into these extreme systems and strongly constrain possible models. In particular, we aim to confirm or exclude the presence of a recoiling SMBH and thus settle the question of whether or not these systems do indeed represent the first detections of this phenomenon.