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Title: The NuSTAR view of nearby Compton-thick active galactic nuclei: the cases of NGC 424, NGC 1320, and IC 2560

We present X-ray spectral analyses for three Seyfert 2 active galactic nuclei (AGNs), NGC 424, NGC 1320, and IC 2560, observed by NuSTAR in the 3-79 keV band. The high quality hard X-ray spectra allow detailed modeling of the Compton reflection component for the first time in these sources. Using quasi-simultaneous NuSTAR and Swift/XRT data, as well as archival XMM-Newton data, we find that all three nuclei are obscured by Compton-thick material with column densities in excess of ∼5 × 10{sup 24} cm{sup –2}, and that their X-ray spectra above 3 keV are dominated by reflection of the intrinsic continuum on Compton-thick material. Due to the very high obscuration, absorbed intrinsic continuum components are not formally required by the data in any of the sources. We constrain the intrinsic photon indices and the column density of the reflecting medium through the shape of the reflection spectra. Using archival multi-wavelength data we recover the intrinsic X-ray luminosities consistent with the broadband spectral energy distributions. Our results are consistent with the reflecting medium being an edge-on clumpy torus with a relatively large global covering factor and overall reflection efficiency of the order of 1%. Given the unambiguous confirmation of the Compton-thick naturemore » of the sources, we investigate whether similar sources are likely to be missed by commonly used selection criteria for Compton-thick AGNs, and explore the possibility of finding their high-redshift counterparts.« less
Authors:
;  [1] ;  [2] ; ; ; ;  [3] ;  [4] ;  [5] ; ;  [6] ; ;  [7] ;  [8] ;  [9] ;  [10] ;  [11] ;  [12] ; ;  [13] more »; « less
  1. Cahill Center for Astronomy and Astrophysics, Caltech, Pasadena, CA 91125 (United States)
  2. INAF Osservatorio Astronomico di Bologna, via Ranzani 1, I-40127, Bologna (Italy)
  3. Department of Physics, Durham University, Durham DH1 3LE (United Kingdom)
  4. Center for Relativistic Astrophysics, School of Physics, Georgia Institute of Technology, Atlanta, GA 30332 (United States)
  5. Instituto de Astrofísica, Facultad de Física, Pontificia Universidad Católica de Chile 306, Santiago 22 (Chile)
  6. Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States)
  7. Department of Astronomy and Astrophysics, The Pennsylvania State University, 525 Davey Lab, University Park, PA 16802 (United States)
  8. Max-Planck-Institut für extraterrestrische Physik, Giessenbachstrasse 1, D-85748 Garching bei München (Germany)
  9. DTU Space, National Space Institute, Technical University of Denmark, Elektrovej 327, DK-2800 Lyngby (Denmark)
  10. Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States)
  11. Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States)
  12. Kavli Institute for Particle Astrophysics and Cosmology, SLAC National Accelerator Laboratory, Menlo Park, CA 94025 (United States)
  13. Dipartimento di Matematica e Fisica, Università degli Studi Roma Tre, via della Vasca Navale 84, I-00146 Roma (Italy)
Publication Date:
OSTI Identifier:
22370412
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 794; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; DENSITY; EFFICIENCY; GALAXY NUCLEI; HARD X RADIATION; KEV RANGE; LUMINOSITY; PHOTONS; RED SHIFT; REFLECTION; SIMULATION; WAVELENGTHS; X-RAY GALAXIES; X-RAY SPECTRA