| Abstract : | Mergers are known to drive gas infall to the centers of galaxies and trigger star formation. This results in the growth of bulges and often triggers active galactic nuclear (AGN) activity. As the galaxies merge and the nuclei come closer, they can form dual or even multiple AGN systems. The supermassive black holes (SMBHs) associated with the AGN will give out gravitational waves at pc scale separations and finally coalesce, leading to the growth of more massive SMBHs. Although galaxy mergers are common, the detection of dual AGN is rare. Their detection is very important as they help us understand the the formation of SMBH binaries, SMBH growth and AGN feedback effects in multiple nuclei systems. There is thus a need for a systematic survey of existing imaging data for the discovery of double nuclei galaxies and dual AGN. Using the Sloan digital sky survey (SDSS) as the target catalog, we have used a novel algorithm called GOTHIC—Graph-bOosTed iterated HIllClimbing — that detects whether a given image of a galaxy has two or more closely separated nuclei. We have tested the algorithm on a sample a million galaxies from the Stripe 82 region in SDSS. We have detected several quasar pairs and a few dual AGN. We discuss the early results of our survey and its implications. |
