Pairs of Supermassive Black Holes

Supermassive black holes, once thought to be theoretical novelties, are now considered to play a major role in many astrophysical┬áphenomena including galaxy evolution. Now that we live in the era of gravitational wave observations, it is interesting to look forward┬áto a time when we can detect gravitational waves from supermassive black hole coalescence. A major question remains: Do┬ásupermassive black holes merge? ┬áI will review the case for supermassive black holes as active players in the universe, focusing on┬áblack hole outflows. Then I will concentrate on my groupÔÇÖs recent work searching for dual and binary supermassive black holes along┬áwith recent developments: (1) closer inspection of time-domain-identified binary candidates; (2) a Bayesian framework for determining┬áduality in a Chandra observation; and (3) spectroscopic and time-domain identification of low-mass-ratio binaries.