[{"DOAJ_listed":"1","year":"2026","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","publisher":"IOP Publishing","title":"Properties of black hole mergers in disks of active galactic nuclei","citation":{"ama":"Tagawa H, Haiman Z, Kocsis B. Properties of black hole mergers in disks of active galactic nuclei. <i>The Astrophysical Journal</i>. 2026;1007(1). doi:<a href=\"https://doi.org/10.3847/1538-4357/ae8760\">10.3847/1538-4357/ae8760</a>","chicago":"Tagawa, Hiromichi, Zoltán Haiman, and Bence Kocsis. “Properties of Black Hole Mergers in Disks of Active Galactic Nuclei.” <i>The Astrophysical Journal</i>. IOP Publishing, 2026. <a href=\"https://doi.org/10.3847/1538-4357/ae8760\">https://doi.org/10.3847/1538-4357/ae8760</a>.","apa":"Tagawa, H., Haiman, Z., &#38; Kocsis, B. (2026). Properties of black hole mergers in disks of active galactic nuclei. <i>The Astrophysical Journal</i>. IOP Publishing. <a href=\"https://doi.org/10.3847/1538-4357/ae8760\">https://doi.org/10.3847/1538-4357/ae8760</a>","short":"H. Tagawa, Z. Haiman, B. Kocsis, The Astrophysical Journal 1007 (2026).","ieee":"H. Tagawa, Z. Haiman, and B. Kocsis, “Properties of black hole mergers in disks of active galactic nuclei,” <i>The Astrophysical Journal</i>, vol. 1007, no. 1. IOP Publishing, 2026.","mla":"Tagawa, Hiromichi, et al. “Properties of Black Hole Mergers in Disks of Active Galactic Nuclei.” <i>The Astrophysical Journal</i>, vol. 1007, no. 1, 67, IOP Publishing, 2026, doi:<a href=\"https://doi.org/10.3847/1538-4357/ae8760\">10.3847/1538-4357/ae8760</a>.","ista":"Tagawa H, Haiman Z, Kocsis B. 2026. Properties of black hole mergers in disks of active galactic nuclei. The Astrophysical Journal. 1007(1), 67."},"publication_identifier":{"issn":["000-4637X"],"eissn":["1538-4357"]},"date_updated":"2026-08-18T09:05:25Z","_id":"22713","publication":"The Astrophysical Journal","volume":1007,"abstract":[{"lang":"eng","text":"Ground-based gravitational-wave (GW) observatories have detected approximately 200 binary black hole (BH) mergers. The astrophysical origin of these events is debated, with evidence suggesting that at least a subset originated from dynamic environments characterized by frequent close encounters. Accretion disks in active galactic nuclei (AGNs) are of particular interest, as certain observed features could be more readily produced within such environments. In this paper, we investigate the expected properties of mergers in these environments, and their dependence on various parameters, using 1D N-body simulations combined with a comprehensive semianalytical model. In our fiducial model, the distributions of masses (m1 and m2) and mass ratios (q ≡ m2/m1 ≤ 1) are similar to those observed. However, they depend strongly on the lifetime and density of the AGN disk and on the number and accretion efficiency of BHs, with higher masses predicted as these quantities increase. The most massive mergers, such as GW231123, can be produced either by efficient gas accretion or by hierarchical mergers among ≥3 generations of BHs. The observed negative correlation between q and the average effective spin (χeff), along with the positive correlation between χeff and the chirp mass (Mchirp), can be explained by a combination of efficient gas accretion, which promotes spin alignment, and hierarchical mergers, which produce high-∣χeff∣ and low-q binaries. Hierarchical mergers can also explain the negative correlation between q and the dispersion of χeff, as well as the positive correlation between ∣χeff∣and Mchirp. We present a comprehensive study on how the expected distribution of each of these quantities depends on model parameters and assumptions, which will aid the interpretation of observed GW population properties."}],"publication_status":"published","article_type":"original","article_number":"67","ddc":["520"],"file":[{"access_level":"open_access","file_size":2246236,"relation":"main_file","success":1,"checksum":"1531fd5997b054d26e99d44ccc7f8ff5","file_name":"2026_AstrophysicalJour_Tagawa.pdf","file_id":"22731","creator":"dernst","date_updated":"2026-08-18T09:01:50Z","date_created":"2026-08-18T09:01:50Z","content_type":"application/pdf"}],"tmp":{"short":"CC BY (4.0)","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","image":"/images/cc_by.png"},"date_created":"2026-08-16T22:01:43Z","type":"journal_article","das_tickbox":"0","doi":"10.3847/1538-4357/ae8760","PlanS_conform":"1","file_date_updated":"2026-08-18T09:01:50Z","month":"08","article_processing_charge":"Yes","language":[{"iso":"eng"}],"scopus_import":"1","researchdata_availability":"no","day":"10","has_accepted_license":"1","issue":"1","OA_place":"publisher","external_id":{"arxiv":["2604.25994"]},"date_published":"2026-08-10T00:00:00Z","oa":1,"OA_type":"gold","department":[{"_id":"ZoHa"}],"oa_version":"Published Version","status":"public","quality_controlled":"1","author":[{"full_name":"Tagawa, Hiromichi","last_name":"Tagawa","first_name":"Hiromichi"},{"first_name":"Zoltán","orcid":"0000-0003-3633-5403","full_name":"Haiman, Zoltán","last_name":"Haiman","id":"7c006e8c-cc0d-11ee-8322-cb904ef76f36"},{"first_name":"Bence","full_name":"Kocsis, Bence","last_name":"Kocsis"}],"supplementarymaterial":"no","acknowledgement":"H.T. is supported by the National Science and Technology Major Project of China (No. 2024ZD1100601) and the National Key R&D Program of China (grant No.2024YFC2207700). Z.H. was supported by NASA grants 80NSSC22K0822 and 80NSSC24K0440. B.K. is supported by the Science and Technology Facilities Council grant No. ST/W000903/1. Simulations were carried out on Cray XD2000 at the Center for Computational Astrophysics, National Astronomical Observatory of Japan.","arxiv":1,"intvolume":"      1007"}]