It is widely appreciated that galaxies are built up
hierarchically via mergers. Since most, if not all, massive
galaxies are believed to harbor a central super-massive
black hole (SMBH), galaxy mergers will result in the formation of binary SMBHs. However, despite decades of searching and strong theoretical reasons to believe they exist, merging binary SMBHs remain extremely difficult to find. I will describe recent efforts by our group to search for such merging binary SMBHs , highlighting new discoveries of kiloparsec-scale binaries. The increasing statistics of binary SMBHs will help us understand the role of mergers in AGN fueling and the interplay between the BH and its host galaxy, and to constrain the predictions for future low-frequency gravitational wave detections from close SMBH binaries and BH coalescence. |
