BAT AGN Spectroscopic Survey – XIII. The nature of the most luminous obscured AGN in the low-redshift universe

Journal Article · 21 August 2019 · Monthly Notices of the Royal Astronomical Society

DOI: https://doi.org/10.1093/mnras/stz2309 · OSTI ID:1574853

Bär, Rudolf E. ^[1]; Trakhtenbrot, Benny  ^[2]; Oh, Kyuseok ^[3]; Koss, Michael J.  ^[4]; Wong, O. Ivy ^[5]; Ricci, Claudio ^[6]; Schawinski, Kevin ^[7]; Weigel, Anna K.  ^[7]; Sartori, Lia F. ^[1]; Ichikawa, Kohei ^[8]; Secrest, Nathan J. ^[9]; Stern, Daniel ^[10]; Pacucci, Fabio  ^[11]; Mushotzky, Richard ^[12]; Powell, Meredith C. ^[13]; Ricci, Federica  ^[14]; Sani, Eleonora ^[15]; Smith, Krista L. ^[16]; Harrison, Fiona A. ^[17]; Lamperti, Isabella ^[18] ; Urry, C. Megan ^[13]

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1. ETH Zurich (Switzerland). Dept. of Physics, Inst. for Particle Physics and Astrophysics
2. ETH Zurich (Switzerland). Dept. Physics; Tel Aviv Univ. (Israel). School of Physics and Astronomy
3. Kyoto Univ. (Japan). Dept. of Astronomy
4. Eureka Scientific, Oakland, CA (United States)
5. The Univ. of Western Australia, Crawley (Australia). International Centre for Radio Astronomy Research
6. Univ. Diego Portales, Santiago (Chile). Núcleo de Astronomía de la Facultad de Ingeniería; Peking Univ., Beijing (China). Kavli Inst. for Astronomy and Astrophysics
7. ETH Zurich (Switzerland). Dept. of Physics, Inst. for Particle Physics and Astrophysics; Modulos AG, Zurich (Switzerland)
8. Tohoku Univ., Sendai (Japan). Frontier Research Inst. for Interdisciplinary Sciences, and Astronomical Inst.
9. U.S. Naval Observatory, Washington, D.C. (United States)
10. California Inst. of Technology (CalTech), Pasadena, CA (United States). Jet Propulsion Lab.
11. Kapteyn Astronomical Inst., Groningen (Netherlands); Harvard Univ., and Smithsonian Astrophysical Observatory, Cambridge, MA (United States). BHI & Clay Fellow
12. Univ. of Maryland, College Park, MD (United States). Dept. of Astronomy, and Joint Space-Science Inst.
13. Yale University, New Haven, CT (United States). Center for Astronomy and Astrophysics, and Physics Dept.
14. Pontificia Univ. Católica de Chile, Santiago (Chile). Inst. de Astrofísica, Facultad de Física
15. European Southern Observatory, Santiago (Chile)
16. SLAC National Accelerator Lab., Menlo Park, CA (United States). Stanford Kavli Inst. for Particle Astrophysics and Cosmology
17. California Inst. of Technology (CalTech), Pasadena, CA (United States). Cahill Center for Astrophysics
18. Univ. College London, (United Kingdom). Dept. of Physics and Astronomy, Astrophysics Group

In this paper, we present a multiwavelength analysis of 28 of the most luminous low-redshift narrow-line, ultra-hard X-ray-selected active galactic nuclei (AGN) drawn from the 70-month Swift/BAT all-sky survey, with bolometric luminosities of $$\log (L_{\rm bol} /{\rm erg\, s}^{-1}) \gtrsim 45.25$$. The broad goal of our study is to determine whether these objects have any distinctive properties, potentially setting them aside from lower luminosity obscured AGN in the local Universe. Our analysis relies on the first data release of the BAT AGN Spectroscopic Survey (BASS/DR1) and on dedicated observations with the VLT, Palomar, and Keck observatories. We find that the vast majority of our sources agree with commonly used AGN selection criteria which are based on emission line ratios and on mid-infrared colours. Our AGN are pre-dominantly hosted in massive galaxies (9.8 ≲ log (M*/M_⊙) ≲ 11.7); based on visual inspection of archival optical images, they appear to be mostly ellipticals. Otherwise, they do not have distinctive properties. Their radio luminosities, determined from publicly available survey data, show a large spread of almost four orders of magnitude – much broader than what is found for lower X-ray luminosity obscured AGN in BASS. Moreover, our sample shows no preferred combination of black hole masses (M_BH) and/or Eddington ratio (λ_Edd, covering 7.5 ≲ log (M_BH/M_⊙) ≲ 10.3 and 0.01 ≲ λ_Edd ≲ 1. Based on the distribution of our sources in the λ_Edd-N_H plane, we conclude that our sample is consistent with a scenario where the amount of obscuring material along the line of sight is determined by radiation pressure exerted by the AGN on the dusty circumnuclear gas.

• Research Organization: SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States)
• Sponsoring Organization: USDOE
• Grant/Contract Number: AC02-76SF00515
• OSTI ID: 1574853
• Journal Information: Monthly Notices of the Royal Astronomical Society, Journal Name: Monthly Notices of the Royal Astronomical Society Journal Issue: 3 Vol. 489; ISSN 0035-8711
• Publisher: Royal Astronomical SocietyCopyright Statement
• Country of Publication: United States
• Language: English