---
_id: '17685'
abstract:
- lang: eng
  text: We propose an observational test for gravitationally recoiling supermassive
    black holes (BHs) in active galactic nuclei, based on a correlation between the
    velocities of BHs relative to their host galaxies, |\Delta v|, and their obscuring
    dust column densities, \Sigma_{dust} (both measured along the line of sight).
    We use toy models for the distribution of recoil velocities, BH trajectories,
    and the geometry of obscuring dust tori in galactic centres, to simulate 2.5x10^5
    random observations of recoiling quasars. BHs with recoil velocities comparable
    to the escape velocity from the galactic centre remain bound to the nucleus, and
    do not fully settle back to the centre of the torus due to dynamical friction
    in a typical quasar lifetime. We find that |\Delta v| and \Sigma_ {dust} for these
    BHs are positively correlated. For obscured (\Sigma_{dust}>0) and for partially
    obscured (0<\Sigma_{dust}<~2.3 g/m^2) quasars with |\Delta v|>=45 km/s, the sample
    correlation coefficient between log10(|\Delta v|) and \Sigma_{dust} is r_{45}
    = 0.28+/-0.02 and r_{45} = 0.13+/-0.02, respectively. Allowing for random +/-100
    km/s errors in |\Delta v| unrelated to the recoil dilutes the correlation for
    the partially obscured quasars to r_{45} = 0.026+/-0.004 measured between |\Delta
    v| and \Sigma_{dust}. A random sample of >~3,500 obscured quasars with |\Delta
    v|>=45 km/s would allow rejection of the no-correlation hypothesis with 3 sigma
    significance 95% of the time. Finally, we find that the fraction of obscured quasars,
    F_{obs}(|\Delta v|), decreases with |\Delta v| from F_{obs}(<10 km/s)>~0.8 to
    F_{obs}(>10^3 km/s)<~0.4. This predicted trend can be compared to the observed
    fraction of type II quasars, and can further test combinations of recoil, trajectory,
    and dust torus models.
article_processing_charge: No
article_type: original
author:
- first_name: P.
  full_name: Raffai, P.
  last_name: Raffai
- first_name: Zoltán
  full_name: Haiman, Zoltán
  id: 7c006e8c-cc0d-11ee-8322-cb904ef76f36
  last_name: Haiman
- first_name: Z.
  full_name: Frei, Z.
  last_name: Frei
citation:
  ama: Raffai P, Haiman Z, Frei Z. A statistical method to search for recoiling supermassive
    black holes in active galactic nuclei. <i>Monthly Notices of the Royal Astronomical
    Society</i>. 2015;455(1):484-492. doi:<a href="https://doi.org/10.1093/mnras/stv2371">10.1093/mnras/stv2371</a>
  apa: Raffai, P., Haiman, Z., &#38; Frei, Z. (2015). A statistical method to search
    for recoiling supermassive black holes in active galactic nuclei. <i>Monthly Notices
    of the Royal Astronomical Society</i>. Oxford University Press. <a href="https://doi.org/10.1093/mnras/stv2371">https://doi.org/10.1093/mnras/stv2371</a>
  chicago: Raffai, P., Zoltán Haiman, and Z. Frei. “A Statistical Method to Search
    for Recoiling Supermassive Black Holes in Active Galactic Nuclei.” <i>Monthly
    Notices of the Royal Astronomical Society</i>. Oxford University Press, 2015.
    <a href="https://doi.org/10.1093/mnras/stv2371">https://doi.org/10.1093/mnras/stv2371</a>.
  ieee: P. Raffai, Z. Haiman, and Z. Frei, “A statistical method to search for recoiling
    supermassive black holes in active galactic nuclei,” <i>Monthly Notices of the
    Royal Astronomical Society</i>, vol. 455, no. 1. Oxford University Press, pp.
    484–492, 2015.
  ista: Raffai P, Haiman Z, Frei Z. 2015. A statistical method to search for recoiling
    supermassive black holes in active galactic nuclei. Monthly Notices of the Royal
    Astronomical Society. 455(1), 484–492.
  mla: Raffai, P., et al. “A Statistical Method to Search for Recoiling Supermassive
    Black Holes in Active Galactic Nuclei.” <i>Monthly Notices of the Royal Astronomical
    Society</i>, vol. 455, no. 1, Oxford University Press, 2015, pp. 484–92, doi:<a
    href="https://doi.org/10.1093/mnras/stv2371">10.1093/mnras/stv2371</a>.
  short: P. Raffai, Z. Haiman, Z. Frei, Monthly Notices of the Royal Astronomical
    Society 455 (2015) 484–492.
date_created: 2024-09-06T08:20:30Z
date_published: 2015-11-02T00:00:00Z
date_updated: 2024-09-25T09:18:47Z
day: '02'
doi: 10.1093/mnras/stv2371
extern: '1'
intvolume: '       455'
issue: '1'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://doi.org/10.1093/mnras/stv2371
month: '11'
oa: 1
oa_version: Published Version
page: 484-492
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: A statistical method to search for recoiling supermassive black holes in active
  galactic nuclei
type: journal_article
user_id: 317138e5-6ab7-11ef-aa6d-ffef3953e345
volume: 455
year: '2015'
...