---
_id: '17602'
abstract:
- lang: eng
  text: Motivated by the increasing number of detections of merging black holes by
    LIGO-VIRGO-KAGRA, black hole (BH) binary mergers in the discs of active galactic
    nuclei (AGNs) is investigated as a possible merger channel. In this pathway, BH
    encounters in the gas disc form mutually bound BH binary systems through interaction
    with the gas in the disc and subsequently inspiral through gravitational torques
    induced by the local gas. To determine the feasibility of this merger pathway,
    we present the first three-dimensional global hydrodynamic simulations of the
    formation and evolution of a stellar-mass BH binaries AGN discs with three different
    AGN disc masses and five different initial radial separations. These 15 simulations
    show binary capture of prograde and retrograde binaries can be successful in a
    range of disc densities including cases well below that of a standard radiatively
    efficient alpha disc, identifying that the majority of these captured binaries
    are then subsequently hardened by the surrounding gas. The eccentricity evolution
    depends strongly on the orbital rotation where prograde binaries are governed
    by gravitational torques form their circumbinary mini disc, with eccentricities
    being damped, while for retrograde binaries the eccentricities are excited to
    >∼ 0.9 by accretion torques. In two cases, retrograde binaries ultimately undergo
    a close periapsis passage which results in a merger via gravitational waves after
    only a few thousand binary orbits. Thus, the merger time-scale can be far shorter
    than the AGN disc lifetime. These simulations support an efficient AGN disc merger
    pathway for BHs.
article_processing_charge: No
article_type: original
author:
- first_name: Connar
  full_name: Rowan, Connar
  last_name: Rowan
- first_name: Tjarda
  full_name: Boekholt, Tjarda
  last_name: Boekholt
- first_name: Bence
  full_name: Kocsis, Bence
  last_name: Kocsis
- first_name: Zoltán
  full_name: Haiman, Zoltán
  id: 7c006e8c-cc0d-11ee-8322-cb904ef76f36
  last_name: Haiman
citation:
  ama: 'Rowan C, Boekholt T, Kocsis B, Haiman Z. Black hole binary formation in AGN
    discs: from isolation to merger. <i>Monthly Notices of the Royal Astronomical
    Society</i>. 2023;524(2):2770-2796. doi:<a href="https://doi.org/10.1093/mnras/stad1926">10.1093/mnras/stad1926</a>'
  apa: 'Rowan, C., Boekholt, T., Kocsis, B., &#38; Haiman, Z. (2023). Black hole binary
    formation in AGN discs: from isolation to merger. <i>Monthly Notices of the Royal
    Astronomical Society</i>. Oxford University Press. <a href="https://doi.org/10.1093/mnras/stad1926">https://doi.org/10.1093/mnras/stad1926</a>'
  chicago: 'Rowan, Connar, Tjarda Boekholt, Bence Kocsis, and Zoltán Haiman. “Black
    Hole Binary Formation in AGN Discs: From Isolation to Merger.” <i>Monthly Notices
    of the Royal Astronomical Society</i>. Oxford University Press, 2023. <a href="https://doi.org/10.1093/mnras/stad1926">https://doi.org/10.1093/mnras/stad1926</a>.'
  ieee: 'C. Rowan, T. Boekholt, B. Kocsis, and Z. Haiman, “Black hole binary formation
    in AGN discs: from isolation to merger,” <i>Monthly Notices of the Royal Astronomical
    Society</i>, vol. 524, no. 2. Oxford University Press, pp. 2770–2796, 2023.'
  ista: 'Rowan C, Boekholt T, Kocsis B, Haiman Z. 2023. Black hole binary formation
    in AGN discs: from isolation to merger. Monthly Notices of the Royal Astronomical
    Society. 524(2), 2770–2796.'
  mla: 'Rowan, Connar, et al. “Black Hole Binary Formation in AGN Discs: From Isolation
    to Merger.” <i>Monthly Notices of the Royal Astronomical Society</i>, vol. 524,
    no. 2, Oxford University Press, 2023, pp. 2770–96, doi:<a href="https://doi.org/10.1093/mnras/stad1926">10.1093/mnras/stad1926</a>.'
  short: C. Rowan, T. Boekholt, B. Kocsis, Z. Haiman, Monthly Notices of the Royal
    Astronomical Society 524 (2023) 2770–2796.
date_created: 2024-09-05T13:09:11Z
date_published: 2023-07-03T00:00:00Z
date_updated: 2024-09-23T13:42:19Z
day: '03'
doi: 10.1093/mnras/stad1926
extern: '1'
intvolume: '       524'
issue: '2'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://doi.org/10.1093/mnras/stad1926
month: '07'
oa: 1
oa_version: Published Version
page: 2770-2796
publication: Monthly Notices of the Royal Astronomical Society
publication_identifier:
  issn:
  - 0035-8711
  - 1365-2966
publication_status: published
publisher: Oxford University Press
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'Black hole binary formation in AGN discs: from isolation to merger'
type: journal_article
user_id: 317138e5-6ab7-11ef-aa6d-ffef3953e345
volume: 524
year: '2023'
...