A Hard X-Ray Test of HCN Enhancements As a Tracer of Embedded Black Hole Growth
Privon,G. C.1; Ricci,C.2,3,4; Aalto,S.5; Viti,S.6; Armus,L.7; Díaz-Santos,T.2,8; González-Alfonso,E.9; Iwasawa,K.10,11; Jeff,D. L.1; Treister,E.12; Bauer,F.12,17,18; Evans,A. S.19,20; Garg,P.1; Herrero-Illana,R.21,22; Mazzarella,J. M.23; Larson,K.24; Blecha,L.15; Barcos-Mu?oz,L.20; Charmandaris,V.16,25; Stierwalt,S.7,13; Pérez-Torres,M. A.14
Source PublicationThe Astrophysical Journal
AbstractAbstract Enhanced emission from the dense gas tracer HCN (relative to HCO+) has been proposed as a signature of active galactic nuclei (AGN). In a previous single-dish millimeter line survey we identified galaxies with HCN/HCO+ (1–0) intensity ratios consistent with those of many AGN but whose mid-infrared spectral diagnostics are consistent with little to no (?15%) contribution of an AGN to the bolometric luminosity. To search for putative heavily obscured AGN, we present and analyze NuSTAR hard X-ray (3–79 keV) observations of four such galaxies from the Great Observatories All-sky LIRG Survey. We find no X-ray evidence for AGN in three of the systems and place strong upper limits on the energetic contribution of any heavily obscured ( ) AGN to their bolometric luminosity. The upper limits on the X-ray flux are presently an order of magnitude below what XDR-driven chemistry models predict are necessary to drive HCN enhancements. In a fourth system we find a hard X-ray excess consistent with the presence of an AGN, but contributing only ~3% of the bolometric luminosity. It is also unclear if the AGN is spatially associated with the HCN enhancement. We further explore the relationship between HCN/HCO+ (for several Jupper levels) and / for a larger sample of systems in the literature. We find no evidence for correlations between the line ratios and the AGN fraction derived from X-rays, indicating that HCN/HCO+ intensity ratios are not driven by the energetic dominance of AGN, nor are they reliable indicators of ongoing supermassive black hole accretion.
KeywordMolecular gas Active galactic nuclei X-ray active galactic nuclei Luminous infrared galaxies Starburst galaxies
WOS IDIOP:0004-637X-893-2-ab8015
PublisherThe American Astronomical Society
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Document Type期刊论文
Affiliation1.Department of Astronomy, University of Florida, P.O. Box 112055, Gainesville, FL 32611, USA;
2.Núcleo de Astronomía de la Facultad de Ingeniería, Universidad Diego Portales, Av. Ejército Libertador 441, Santiago, Chile
3.Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871, People's Republic of China
4.George Mason University, Department of Physics & Astronomy, MS 3F3, 4400 University Drive, Fairfax, VA 22030, USA
5.Department of Space, Earth and Environment, Chalmers University of Technology, Onsala Space Observatory, SE-439 92, Onsala, Sweden
6.Department of Physics and Astronomy, University College London, Gower Street, London, WC1E 6BT, UK
7.IPAC, MC 314-6, Caltech, 1200 E. California Boulevard, Pasadena, CA 91125, USA
8.Chinese Academy of Sciences South America Center for Astronomy, National Astronomical Observatories, CAS, Beijing 100101, People's Republic of China
9.Universidad de Alcalá, Departamento de Física y Matemáticas, Campus Universitario, E-28871 Alcalá de Henares, Madrid, Spain
10.Institut de Ciències del Cosmos (ICCUB), Universitat de Barcelona (IEEC-UB), Martí i Franquès, 1, E-08028 Barcelona, Spain
11.ICREA, Pg. Lluís Companys 23, E-08010 Barcelona, Spain
12.Instituto de Astrof?ica, Facultad de Física, Pontificia Universidad Católica de Chile, Casilla 306, Santiago 22, Chile
13.Department of Physics, Occidental College, Los Angeles, CA 90041, USA
14.Instituto de Astrofísica de Andalucía—CSIC, P.O. Box 3004, E-18008, Granada, Spain
15.Department of Physics, University of Florida, P.O. Box 118440, Gainesville, FL 32611, USA
16.Institute of Astrophysics, Foundation for Research and Technology-Hellas, GR-71110, Heraklion, Greece
17.Millennium Institute of Astrophysics (MAS), Nuncio Monse?or Sótero Sanz 100, Providencia, Santiago, Chile
18.Space Science Institute, 4750 Walnut Street, Suite 205, Boulder, CO 80301, USA
19.Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904, USA
20.National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903, USA
21.European Southern Observatory (ESO), Alonso de Córdova 3107, Vitacura, Casilla 19001, Santiago de Chile, Chile
22.Institute of Space Sciences (ICE, CSIC), Campus UAB, Carrer de Magrans, E-08193 Barcelona, Spain
23.IPAC, MC 100-22, California Institute of Technology, Pasadena, CA 91125, USA
24.Department of Astronomy, California Institute of Technology, 1200 E. California Boulevard, Pasadena, CA 91125, USA
25.Department of Physics, University of Crete, GR-71003, Heraklion, Greece
Recommended Citation
GB/T 7714
Privon,G. C.,Ricci,C.,Aalto,S.,et al. A Hard X-Ray Test of HCN Enhancements As a Tracer of Embedded Black Hole Growth[J]. The Astrophysical Journal,2020,893(2).
APA Privon,G. C..,Ricci,C..,Aalto,S..,Viti,S..,Armus,L..,...&Pérez-Torres,M. A..(2020).A Hard X-Ray Test of HCN Enhancements As a Tracer of Embedded Black Hole Growth.The Astrophysical Journal,893(2).
MLA Privon,G. C.,et al."A Hard X-Ray Test of HCN Enhancements As a Tracer of Embedded Black Hole Growth".The Astrophysical Journal 893.2(2020).
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