Unveiling Sub-pc Supermassive Black Hole Binary Candidates in Active Galactic Nuclei

  title={Unveiling Sub-pc Supermassive Black Hole Binary Candidates in Active Galactic Nuclei},
  author={Roberto Serafinelli and Paola Severgnini and Valentina Braito and Roberto Della Ceca and Cristian Vignali and Filippo Ambrosino and Claudia Cicone and Alessandra Zaino and Massimo Dotti and Alberto Sesana and Vittoria E. Gianolli and Lucia Ballo and Valentina La Parola and Gabriele A. Matzeu},
  journal={The Astrophysical Journal},
The elusive supermassive black hole binaries (SMBHBs) are thought to be the penultimate stage of galaxy mergers, preceding a final coalescence phase. SMBHBs are sources of continuous gravitational waves, possibly detectable by pulsar timing arrays; the identification of candidates could help in performing targeted gravitational wave searches. Due to SMBHBs’ origin in the innermost parts of active galactic nuclei (AGN), X-rays are a promising tool for unveiling their presence, by means of either… 

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