CaltechAUTHORS
Published July 2022 | Version Published + Accepted Version
Journal Article Open

BASS. XXX. Distribution Functions of DR2 Eddington Ratios, Black Hole Masses, and X-Ray Luminosities

Creators

  • 1. ROR icon Dartmouth College
  • 2. ROR icon Tel Aviv University
  • 3. ROR icon Eureka Scientific
  • 4. ROR icon Space Science Institute
  • 5. ROR icon Yale University
  • 6. ROR icon Diego Portales University
  • 7. ROR icon Peking University
  • 8. ROR icon Pontificia Universidad Católica de Chile
  • 9. ROR icon Millennium Institute of Astrophysics
  • 10. ROR icon Kyoto University
  • 11. ROR icon University of Maryland, College Park
  • 12. ROR icon University of Bologna
  • 13. ROR icon Korea Astronomy and Space Science Institute
  • 14. ROR icon European Southern Observatory
  • 15. ROR icon University of Bonn
  • 16. ROR icon Jet Propulsion Lab
  • 17. ROR icon Stanford University
  • 18. ROR icon Leiden University
  • 19. ROR icon Tohoku University
  • 20. ROR icon Astronomy and Space
  • 21. ROR icon University of Western Australia
  • 22. ROR icon California Institute of Technology

Abstract

We determine the low-redshift X-ray luminosity function, active black hole mass function (BHMF), and Eddington ratio distribution function (ERDF) for both unobscured (Type 1) and obscured (Type 2) active galactic nuclei (AGNs), using the unprecedented spectroscopic completeness of the BAT AGN Spectroscopic Survey (BASS) data release 2. In addition to a straightforward 1/Vₘₐₓ approach, we also compute the intrinsic distributions, accounting for sample truncation by employing a forward-modeling approach to recover the observed BHMF and ERDF. As previous BHMFs and ERDFs have been robustly determined only for samples of bright, broad-line (Type 1) AGNs and/or quasars, ours are the first directly observationally constrained BHMF and ERDF of Type 2 AGNs. We find that after accounting for all observational biases, the intrinsic ERDF of Type 2 AGNs is significantly more skewed toward lower Eddington ratios than the intrinsic ERDF of Type 1 AGNs. This result supports the radiation-regulated unification scenario, in which radiation pressure dictates the geometry of the dusty obscuring structure around an AGN. Calculating the ERDFs in two separate mass bins, we verify that the derived shape is consistent, validating the assumption that the ERDF (shape) is mass-independent. We report the local AGN duty cycle as a function of mass and Eddington ratio, by comparing the BASS active BHMF with the local mass function for all supermassive black holes. We also present the log N − log S of the Swift/BAT 70 month sources.

Additional Information

© 2022. The Author(s). Published by the American Astronomical Society. Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Received 2021 July 4; revised 2022 January 20; accepted 2022 February 5; published 2022 July 15. The BAT AGN Spectroscopic Survey Data Release 2. We thank the anonymous reviewers for their constructive and detailed comments, which helped us improve the quality of this paper. T.T.A. and R.C.H. acknowledge support from NASA, through ADAP award 80NSSC19K0580. R.C.H. also acknowledges support from the National Science Foundation, through CAREER award 1554584. B.T. acknowledges support from the Israel Science Foundation (grant No. 1849/19) and from the European Research Council (ERC), under the European Union's Horizon 2020 research and innovation program (grant agreement number 950533). M.K. acknowledges support from NASA, through ADAP award NNH16CT03C. C.M.U. acknowledges support from the National Science Foundation, under grant No. AST-1715512. C.R. acknowledges support from the Fondecyt Iniciacion, grant 11190831. We acknowledge support from ANID-Chile Basal AFB-170002 and FB210003 (E.T., F.E.B.), FONDECYT Regular 1200495 and 1190818 (E.T., F.E.B.), ANID Anillo ACT172033 (E.T.), Millennium Nucleus NCN19_058 (TITANs; E.T.), and the Millennium Science Initiative Program—ICN12_009 (F.E.B.). K.O. acknowledges support from the National Research Foundation of Korea (NRF-2020R1C1C1005462). The work of K.I. is supported by the Japan Society for the Promotion of Science (JSPS) KAKENHI (18K13584, 20H01939). J.d.B. acknowledges funding from the European Research Council (ERC), under the European Union's Horizon 2020 research and innovation program (grant agreement No.726384/Empire). This work was performed in part at the Aspen Center for Physics, which is supported by National Science Foundation grant PHY-1607611. This research made use of Astropy (Astropy Collaboration et al. 2013; Price-Whelan et al. 2018), Matplotlib (Hunter 2007), Emcee (Foreman-Mackey et al. 2013), NumPy (van der Walt et al. 2011), Topcat (Taylor 2005), xpec and pyxpsec (Arnaud 1996), and ChainConsumer (Hinton 2016).

Attached Files

Published - Ananna_2022_ApJS_261_9.pdf

Accepted Version - 2201.05603.pdf

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Additional details

Identifiers

Eprint ID
115882
Resolver ID
CaltechAUTHORS:20220727-44653000

Related works

Describes
https://arxiv.org/abs/2201.05603 (URL)

Funding

NASA
80NSSC19K0580
NSF
AST-1554584
Israel Science Foundation
1849/19
European Research Council (ERC)
950533
NASA
NNH16CT03C
NSF
AST-1715512
Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT)
11190831
BASAL-CATA
AFB-170002
Agencia Nacional de Investigación y Desarrollo (ANID)
FB210003
Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT)
1200495
Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT)
1190818
Comisión Nacional de Investigación Científica y Tecnológica (CONICYT)
ACT172033
Agencia Nacional de Investigación y Desarrollo (ANID)
NCN19_058
Comisión Nacional de Investigación Científica y Tecnológica (CONICYT)
ICN12_009
National Research Foundation of Korea
NRF-2020R1C1C1005462
Japan Society for the Promotion of Science (JSPS)
18K13584
Japan Society for the Promotion of Science (JSPS)
20H01939
European Research Council (ERC)
726384
NSF
PHY-1607611

Dates

Created
2022-07-29
Created from EPrint's datestamp field
Updated
2022-07-29
Created from EPrint's last_modified field

Caltech Custom Metadata

Caltech groups
Astronomy Department , Space Radiation Laboratory