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Title: NUSTAR and SUZAKU X-ray spectroscopy of NGC 4151: Evidence for reflection from the inner accretion disk

We present X-ray timing and spectral analyses of simultaneous 150 ks Nuclear Spectroscopic Telescope Array (NuSTAR) and Suzaku X-ray observations of the Seyfert 1.5 galaxy NGC 4151. We disentangle the continuum emission, absorption, and reflection properties of the active galactic nucleus (AGN) by applying inner accretion disk reflection and absorption-dominated models. With a time-averaged spectral analysis, we find strong evidence for relativistic reflection from the inner accretion disk. We find that relativistic emission arises from a highly ionized inner accretion disk with a steep emissivity profile, which suggests an intense, compact illuminating source. We find a preliminary, near-maximal black hole spin $$a\gt 0.9$$ accounting for statistical and systematic modeling errors. We find a relatively moderate reflection fraction with respect to predictions for the lamp post geometry, in which the illuminating corona is modeled as a point source. Through a time-resolved spectral analysis, we find that modest coronal and inner disk reflection (IDR) flux variation drives the spectral variability during the observations. As a result, we discuss various physical scenarios for the IDR model and we find that a compact corona is consistent with the observed features.
 [1] ;  [2] ;  [3] ;  [4] ;  [5] ;  [6] ;  [5] ;  [7] ;  [2] ;  [8] ;  [9] ;  [2] ;  [9] ;  [10] ;  [9] ;  [11] ;  [12] ;  [12] ;  [13] ;  [9] more »;  [9] ;  [14] « less
  1. Boston Univ., Boston, MA (United States)
  2. Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States)
  3. Georgia Inst. of Technology, Atlanta, GA (United States)
  4. Pontificia Univ. Catolica de Chile, Santiago (Chile); Millennium Institute of Astrophysics, Santiago (Chile); Space Science Institute, Boulder, CO (United States)
  5. Univ. of California, Berkeley, CA (United States)
  6. Technical Univ. of Denmark, Lyngby (Denmark)
  7. Dr. Karl Remis-Observatory and Erlangen Centre for Astroparticle Physics, Bamberg (Germany)
  8. Univ. of Cambridge, Cambridge (United Kingdom)
  9. California Inst. of Technology (CalTech), Pasadena, CA (United States)
  10. Columbia Univ., New York, NY (United States)
  11. SLAC National Accelerator Lab., Menlo Park, CA (United States)
  12. Univ. degli Studi Roma Tre, Roma (Italy)
  13. Univ. of Maryland, College Park, MD (United States)
  14. Univ. of Michigan, Ann Arbor, MI (United States)
Publication Date:
OSTI Identifier:
Report Number(s):
Journal ID: ISSN 1538-4357; arXiv:1504.07950
Grant/Contract Number:
Accepted Manuscript
Journal Name:
The Astrophysical Journal (Online)
Additional Journal Information:
Journal Name: The Astrophysical Journal (Online); Journal Volume: 806; Journal Issue: 2; Journal ID: ISSN 1538-4357
Institute of Physics (IOP)
Research Org:
SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States)
Sponsoring Org:
National Aeronautics and Space Administration (NASA); USDOE Office of Science (SC)
Country of Publication:
United States
79 ASTRONOMY AND ASTROPHYSICS astrophysics; ASTRO; GRQC; accretion; accretion disks; black hole physics; galaxies: active; galaxies: individual (NGC 4151); galaxies: Seyfert; X-rays: galaxies