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Arxiv: Constraints on Supermassive Black Hole Binaries from JWST and NANOGrav Published: 1/8/2024 9:00:00 PM Updated: 3/25/2024 7:04:58 PM

Paper abstract: We use the recent statistics of dual active galactic nuclei (AGN) in theJames \ Webb \ Space \ Telescope (JWST) data at z ~ 3.4 to address twoaspects of the feedback and evolution scenarios of supermassive black holebinaries (SMBHB). We find that the JWST data provide evidence for the membersof a binary black hole being 'lit' at the same time, rather than independently-- a scenario which is consistent with gas-rich mergers being responsible forconcurrent AGN activity. This conclusion is supported by the recent NANOGravPulsar Timing Array (PTA) measurements, whose upper limits on the stochasticgravitational wave strain amplitude lie below those expected from extrapolatingthe dual AGN fraction. The results indicate either a 'stalling' of the binariesat the separations probed by NANOGrav, or rapid gas-driven inspirals.