We present high-resolution (∼50−100 pc) Atacama Large Millimeter Array (ALMA) observations of 12CO(2-1) or 12CO(1-0) emission in seven local (z≲ 0.05) major mergers -- five of which are dual active galactic nuclei (AGN) systems, and two of which are single AGN systems. We model the molecular gas kinematics through rotating disk profiles using a Bayesian Markov chain Monte Carlo approach. The residuals were then used to isolate non-rotating components of the molecular gas -- the most likely contributor to future SMBH growth. We find that more massive SMBHs have higher surface densities of non-rotating molecular gas within their sphere of influence. This potential molecular gas supply, however, does not correlate with the current accretion efficiency of the SMBHs, suggesting that only a fraction of the observed non-rotating gas is currently reaching the SMBH. Finally, we tentatively find no significant differences in the nuclear molecular gas masses of single AGN and dual AGN hosts, both within the SMBH sphere of influence and within the central kiloparsec. Our results indicate that the probability of occurrence of the dual AGN phenomenon is likely dependent on AGN variability and/or obscuration rather than the availability of molecular gas in the nuclear regions.
@article{arxiv.2510.23742,
title = {Molecular Gas in Major Mergers Hosting Dual and Single AGN at <10 kpc Nuclear Separations},
author = {Makoto A. Johnstone and Ezequiel Treister and Franz E. Bauer and Chin-Shin Chang and Claudia Cicone and Michael J. Koss and Ignacio del Moral-Castro and Francisco Muller-Sanchez and George C. Privon and Claudio Ricci and Nick Scoville and Giacomo Venturi and Loreto Barcos-Muñoz and Lee Armus and Laura Blecha and Caitlin Casey and Julia Comerford and Aaron Evans and Taiki Kawamuro and Anne M. Medling and Hugo Messias and Neil Nagar and Alejandra Rojas and David Sanders and Benny Trakhtenbrot and Vivian U and Meg Urry},
journal= {arXiv preprint arXiv:2510.23742},
year = {2025}
}