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IC 3639—A New Bona Fide Compton-Thick AGN Unveiled by NuSTAR

Boorman, Peter G. and Gandhi, P. and Alexander, D. M. and Annuar, A. and Ballantyne, D. R. and Bauer, F. and Boggs, S. E. and Brandt, W. N. and Brightman, M. and Christensen, F. E. and Craig, W. W. and Farrah, D. and Hailey, C. J. and Harrison, F. A. and Hönig, S. F. and Koss, M. and LaMassa, S. M. and Masini, A. and Ricci, C. and Risaliti, G. and Stern, D. and Zhang, W. W. (2016) IC 3639—A New Bona Fide Compton-Thick AGN Unveiled by NuSTAR. Astrophysical Journal, 833 (2). Art. No. 245. ISSN 0004-637X. doi:10.3847/1538-4357/833/2/245.

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We analyze high-quality NuSTAR observations of the local (z = 0.011) Seyfert 2 active galactic nucleus (AGN) IC 3639, in conjunction with archival Suzaku and Chandra data. This provides the first broadband X-ray spectral analysis of the source, spanning nearly two decades in energy (0.5–30 keV). Previous X-ray observations of the source below 10 keV indicated strong reflection/obscuration on the basis of a pronounced iron fluorescence line at 6.4 keV. The hard X-ray energy coverage of NuSTAR, together with self-consistent toroidal reprocessing models, enables direct broadband constraints on the obscuring column density of the source. We find the source to be heavily Compton-thick (CTK) with an obscuring column in excess of 3.6 x 10^(24) cm^(−2), unconstrained at the upper end. We further find an intrinsic 2–10 keV luminosity of log_(10)(L_(2-10keV) [erg s^(-1)])={43.4}_(-1.1)^(+0.6 to 90% confidence, almost 400 times the observed flux, and consistent with various multiwavelength diagnostics. Such a high ratio of intrinsic to observed flux, in addition to an Fe-Kα fluorescence line equivalent width exceeding 2 keV, is extreme among known bona fide CTK AGNs, which we suggest are both due to the high level of obscuration present around IC 3639. Our study demonstrates that broadband spectroscopic modeling with NuSTAR enables large corrections for obscuration to be carried out robustly and emphasizes the need for improved modeling of AGN tori showing intense iron fluorescence.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Boorman, Peter G.0000-0001-9379-4716
Gandhi, P.0000-0003-3105-2615
Alexander, D. M.0000-0002-5896-6313
Annuar, A.0000-0003-0387-1429
Ballantyne, D. R.0000-0001-8128-6976
Bauer, F.0000-0002-8686-8737
Boggs, S. E.0000-0001-9567-4224
Brandt, W. N.0000-0002-0167-2453
Brightman, M.0000-0002-8147-2602
Christensen, F. E.0000-0001-5679-1946
Farrah, D.0000-0003-1748-2010
Harrison, F. A.0000-0003-2992-8024
Koss, M.0000-0002-7998-9581
LaMassa, S. M.0000-0002-5907-3330
Masini, A.0000-0002-7100-9366
Ricci, C.0000-0001-5231-2645
Stern, D.0000-0003-2686-9241
Zhang, W. W.0000-0002-1426-9698
Additional Information:© 2016 American Astronomical Society. Received 2016 June 27. Accepted 2016 October 26. Published 2016 December 20. We thank the anonymous referee for the invaluable comments that helped to improve this paper. This work made use of data from the NuSTAR mission, a project led by the California Institute of Technology, managed by the Jet Propulsion Laboratory, and funded by the National Aeronautics and Space Administration. We thank the NuSTAR Operations, Software, and Calibration teams for support with the execution and analysis of these observations. This research has made use of the NuSTAR Data Analysis Software (NuSTARDAS) jointly developed by the ASI Science Data Center (ASDC, Italy) and the California Institute of Technology (USA). The scientific results reported in this article are based on observations made by the ChandraX-ray Observatory. This research has made use of data, software, and/or Web tools obtained from the High Energy Astrophysics Science Archive Research Center (HEASARC), a service of the Astrophysics Science Division at NASA/GSFC and of the Smithsonian Astrophysical Observatory's High Energy Astrophysics Division. This research has made use of the NASA/IPAC Extragalactic Database (NED), which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. This research has made use of data obtained from the Suzaku satellite, a collaborative mission between the space agencies of Japan (JAXA) and the USA (NASA). This publication makes use of data products from the Wide-field Infrared Survey Explorer, which is a joint project of the University of California, Los Angeles, and the Jet Propulsion Laboratory/California Institute of Technology, funded by the National Aeronautics and Space Administration. P.B. thanks STFC and the RAS for funding. P.G. thanks STFC for support (grant reference ST/J003697/2). A.A. acknowledges financial support from Majlis Amanah Rakyat (MARA), Malaysia. D. M. A. acknowledges the Science and Technology Facilities Council (DMA; ST/L00075X/1). W.N.B. acknowledges Caltech NuSTAR subcontract 44A-1092750 and the VM Willaman Endowment. S.F.H. acknowledges support from the European Research Council under Horizon 2020 grant ERC-2015-StG-677117. M.K. acknowledges support from the Swiss National Science Foundation (SNSF) through the Ambizione fellowship grant PZ00P2_154799/1. S.M.L. acknowledges support by an appointment to the NASA Postdoctoral Program at the NASA Goddard Space Flight Center, administered by the Universities Space Research Association under contract with NASA. A.M. acknowledges support from the ASI/INAF grant I/037/12/0-011/13. F.E.B. and C.R. acknowledge support from NASA NuSTAR A01 Award NNX15AV27G, CONICYT-Chile grants Basal-CATA PFB-06/2007, FONDECYT Regular 1141218 and 1151408, "EMBIGGEN" Anillo ACT1101, the China-CONICYT, and the Ministry of Economy, Development, and Tourism's Millennium Science Initiative through grant IC120009, awarded to The Millennium Institute of Astrophysics, MAS. Facilities: NuSTAR, Suzaku, Chandra.
Group:NuSTAR, Space Radiation Laboratory, Infrared Processing and Analysis Center (IPAC)
Funding AgencyGrant Number
Royal Astronomical SocietyUNSPECIFIED
Science and Technology Facilities Council (STFC)ST/J003697/2
Majlis Amanah Rakyat (MARA)UNSPECIFIED
Science and Technology Facilities Council (STFC)ST/L00075X/1
Caltech NuSTAR subcontract44A-1092750
Caltech VM Willaman EndowmnentUNSPECIFIED
European Research Council (ERC)ERC-2015-StG-677117
Swiss National Science Foundation (SNSF)PZ00P2_154799/1
Agenzia Spaziale Italiana (ASI)I/037/12/0-011/13
Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT)1141218
Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT)1151408
Comisión Nacional de Investigación Científica y Tecnológica (CONICYT)Anillo ACT1101
Iniciativa Científica Milenio del Ministerio de Economía, Fomento y TurismoIC120009
Millennium Institute of Astrophysics (MAS)UNSPECIFIED
Istituto Nazionale di Astrofisica (INAF)UNSPECIFIED
Subject Keywords:galaxies: active; galaxies: nuclei; galaxies: Seyfert; techniques: spectroscopic; X-rays: galaxies; X-rays: individual (IC 3639)
Issue or Number:2
Record Number:CaltechAUTHORS:20161220-081623292
Persistent URL:
Official Citation:Peter G. Boorman et al 2016 ApJ 833 245
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:72962
Deposited By: Ruth Sustaita
Deposited On:20 Dec 2016 17:07
Last Modified:11 Nov 2021 05:09

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