Is Extended Hard X-Ray Emission Ubiquitous in Compton-thick AGN?

The recent Chandra discovery of extended ∼kiloparsec-scale hard (>3 keV) X-ray emission in nearby Compton-thick (CT) active galactic nuclei (AGN) opens a new window to improving AGN torus modeling and investigating how the central supermassive black hole interacts with and impacts the host galaxy. Since there are only a handful of detections so far, we need to establish a statistical sample to determine the ubiquity of the extended hard X-ray emission in CT AGN and quantify the amount and extent of this component. In this paper, we present the spatial analysis results of a pilot Chandra imaging survey of seven nearby ( 0.006 < z < 0.013 ) CT AGN selected from the Swift-BAT spectroscopic AGN survey. We find that five out of the seven CT AGN show extended emission in the 3–7 keV band detected at >3σ above the Chandra point-spread function (PSF), with ∼12%–22% of the total emission in the extended components. ESO 137-G034 and NGC 3281 display biconical ionization structures with extended hard X-ray emission reaching kiloparsec scales (∼1.9 and 3.5 kpc in diameter). The other three show extended hard X-ray emission above the PSF out to at least ∼360 pc in radius. We find a trend that a minimum 3–7 keV count rate of 0.01 counts s−1 and total excess fraction >20% are required to detect a prominent extended hard X-ray component. Given that this extended hard X-ray component appears to be relatively common in this uniformly selected CT AGN sample, we further discuss the implications for torus modeling and AGN feedback.

[1]  M. Karovska,et al.  Chandra Observations of NGC 7212: Large-scale Extended Hard X-Ray Emission , 2020, The Astrophysical Journal.

[2]  M. Elvis,et al.  Multiphase Gas Flows in the Nearby Seyfert Galaxy ESO428–G014. Paper I , 2019, The Astrophysical Journal.

[3]  S. Paltani,et al.  RefleX: X-ray absorption and reflection in active galactic nuclei for arbitrary geometries , 2019, 1906.08824.

[4]  Y. Fukazawa,et al.  XCLUMPY: X-Ray Spectral Model from Clumpy Torus and Its Application to the Circinus Galaxy , 2019, The Astrophysical Journal.

[5]  M. Imanishi,et al.  A Chandra and ALMA study of X-ray-irradiated gas in the central ∼100 pc of the Circinus galaxy , 2019, Publications of the Astronomical Society of Japan.

[6]  R. Davies,et al.  An Accreting Supermassive Black Hole Irradiating Molecular Gas in NGC 2110 , 2019, The Astrophysical Journal.

[7]  A. Comastri,et al.  Compton-thick AGNs in the NuSTAR Era. III. A Systematic Study of the Torus Covering Factor , 2018, The Astrophysical Journal.

[8]  M. Karovska,et al.  Deep Chandra Observations of ESO 428-G014. IV. The Morphology of the Nuclear Region in the Hard Continuum and Fe Kα Line , 2018, The Astrophysical Journal.

[9]  M. Karovska,et al.  CHEERS Results from NGC 3393. III. Chandra X-Ray Spectroscopy of the Narrow Line Region , 2018, The Astrophysical Journal.

[10]  A. Akylas,et al.  NuSTAR observations of heavily obscured Swift/BAT AGNs: Constraints on the Compton-thick AGNs fraction , 2018, Astronomy & Astrophysics.

[11]  R. Sutherland,et al.  The jet-ISM interactions in IC 5063 , 2018, 1801.06875.

[12]  P. Gandhi,et al.  New Spectral Model for Constraining Torus Covering Factors from Broadband X-Ray Spectra of Active Galactic Nuclei , 2018, 1801.04938.

[13]  L. Ho,et al.  BAT AGN Spectroscopic Survey. V. X-Ray Properties of the Swift/BAT 70-month AGN Catalog , 2017, 1709.03989.

[14]  C. R. Almeida,et al.  Nuclear obscuration in active galactic nuclei , 2017, Nature Astronomy.

[15]  K. Schawinski,et al.  BAT AGN Spectroscopic Survey. I. Spectral Measurements, Derived Quantities, and AGN Demographics , 2017, 1707.08123.

[16]  S. Bianchi,et al.  Spatially resolved Fe K spectroscopy of NGC 4945 , 2017, 1706.06362.

[17]  M. Karovska,et al.  Discovery of a Kiloparsec Extended Hard X-Ray Continuum and Fe–Kα from the Compton Thick AGN ESO 428-G014 , 2017, 1705.10680.

[18]  M. Karovska,et al.  CHEERS Results from NGC 3393. II. Investigating the Extended Narrow-line Region Using Deep Chandra Observations and Hubble Space Telescope Narrow-line Imaging , 2016, 1611.05880.

[19]  D. Walton,et al.  THE GEOMETRY OF THE INFRARED AND X-RAY OBSCURER IN A DUSTY HYPERLUMINOUS QUASAR , 2016, 1606.05649.

[20]  P. Gandhi,et al.  COMPTON-THICK ACCRETION IN THE LOCAL UNIVERSE , 2015, 1603.04852.

[21]  W. N. Brandt,et al.  BROADBAND OBSERVATIONS OF THE COMPTON-THICK NUCLEUS OF NGC 3393 , 2015, 1505.03524.

[22]  H. Netzer.  Revisiting the Unified Model of Active Galactic Nuclei , 2015, 1505.00811.

[23]  Durham,et al.  NuSTAR SPECTROSCOPY OF MULTI-COMPONENT X-RAY REFLECTION FROM NGC 1068 , 2014, 1411.0670.

[24]  D. Walton,et al.  THE NuSTAR VIEW OF NEARBY COMPTON-THICK ACTIVE GALACTIC NUCLEI: THE CASES OF NGC 424, NGC 1320, AND IC 2560 , 2014, 1408.5414.

[25]  D. Walton,et al.  THE 2–79 keV X-RAY SPECTRUM OF THE CIRCINUS GALAXY WITH NuSTAR, XMM-Newton, AND CHANDRA: A FULLY COMPTON-THICK ACTIVE GALACTIC NUCLEUS , 2014, 1406.3345.

[26]  M. Karovska,et al.  CHEERS RESULTS ON Mrk 573: A STUDY OF DEEP CHANDRA OBSERVATIONS , 2012, 1203.1279.

[27]  M. Elitzur.  ON THE UNIFICATION OF ACTIVE GALACTIC NUCLEI , 2012, 1202.1776.

[28]  S. Bianchi,et al.  The X-ray reflector in NGC 4945: a time- and space-resolved portrait , 2012, 1202.1279.

[29]  T. Yaqoob,et al.  An X-ray spectral model for Compton-thick toroidal reprocessors , 2009, 0905.3188.

[30]  M. Elitzur.  The toroidal obscuration of active galactic nuclei , 2008, 0805.3699.

[31]  S. Muller,et al.  The Circumnuclear Molecular Gas in the Seyfert Galaxy NGC 4945 , 2007, 0709.3960.

[32]  Michael A. Nowak,et al.  CIAO: Chandra's data analysis system , 2006, SPIE Astronomical Telescopes + Instrumentation.

[33]  T. Heckman,et al.  Penetrating the Deep Cover of Compton-thick Active Galactic Nuclei , 2006, astro-ph/0605438.

[34]  S. Bianchi,et al.  The soft X-ray/NLR connection: a single photoionized medium? , 2005, astro-ph/0511216.

[35]  A. Kinney,et al.  A Hubble Space Telescope Survey of Extended [O III] λ5007 Emission in a Far-Infrared Selected Sample of Seyfert Galaxies: Observations , 2003, astro-ph/0307254.

[36]  A. Kinney,et al.  A Hubble Space Telescope Survey of Extended [O III] λ5007 Å Emission in a Far-Infrared-Selected Sample of Seyfert Galaxies: Results , 2003, astro-ph/0307255.

[37]  Ž. Ivezić,et al.  Dust Emission from Active Galactic Nuclei , 2002, astro-ph/0202405.

[38]  P. Ferruit,et al.  Hubble Space Telescope WFPC2 Imaging of a Sample of Early-Type Seyfert Galaxies , 2000 .

[39]  M. Allen,et al.  Radio continuum morphology of southern Seyfert galaxies , 1999, astro-ph/9905006.

[40]  Astronomy,et al.  A Hubble Space Telescope Imaging Survey of Nearby Active Galactic Nuclei , 1998, astro-ph/9803123.

[41]  P. Padovani,et al.  UNIFIED SCHEMES FOR RADIO-LOUD ACTIVE GALACTIC NUCLEI , 1995, astro-ph/9506063.

[42]  Robert Antonucci,et al.  Unified models for active galactic nuclei and quasars , 1993 .

[43]  J. Baldwin,et al.  The ionization cone, obscured nucleus, and gaseous outflow in NGC 3281 - A prototypical Seyfert 2 galaxy? , 1992 .

[44]  Philippe Veron,et al.  A catalogue of quasars and active nuclei: 12th edition , 1998 .

[45]  R. Barvainis,et al.  Hot Dust and the Near-Infrared Bump in the Continuum Spectra of Quasars and Active Galactic Nuclei , 1987 .

[46]  V. Balzano.  Star-burst galactic nuclei , 1983 .