The broad-band X-ray spectrum of IC 4329A from a joint NuSTAR/Suzaku observation

Journal Article · Tue Jun 10 00:00:00 EDT 2014 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/788/1/61· OSTI ID:22356676

Brenneman, L. W.; Elvis, M. ^[1]; Madejski, G. ^[2]; Fuerst, F.; Harrison, F. A.; Grefenstette, B. W.; Madsen, K. K.; Rivers, E.; Walton, D. J. ^[3]; Matt, G.; Marinucci, A. ^[4]; Ballantyne, D. R. ^[5]; Boggs, S. E. ^[6]; Christensen, F. E.; Craig, W. W. ^[7]; Fabian, A. C. ^[8]; Hailey, C. J. ^[9]; Stern, D. ^[10]; Zhang, W. W. ^[11]

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1. Harvard-Smithsonian CfA, 60 Garden St., MS-67, Cambridge, MA 02138 (United States)
2. Kavli Institute for Particle Astrophysics and Cosmology, SLAC National Accelerator Laboratory, Menlo Park, CA 94025 (United States)
3. Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States)
4. Dipartimento di Matematica e Fisica, Università Roma Tre, via della Vasca Navale 84, I-00146 Roma (Italy)
5. Center for Relativistic Astrophysics, School of Physics, Georgia Institute of Technology, Atlanta, GA 30332 (United States)
6. Space Science Laboratory, University of California, Berkeley, CA 94720 (United States)
7. DTU Space-National Space Institute, Technical University of Denmark, Elektrovej 327, DK-2800 Lyngby (Denmark)
8. Institute of Astronomy, Madingley Road, Cambridge CB3 0HA (United Kingdom)
9. Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States)
10. Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States)
11. NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

We have obtained a deep, simultaneous observation of the bright, nearby Seyfert galaxy IC 4329A with Suzaku and NuSTAR. Through a detailed spectral analysis, we are able to robustly separate the continuum, absorption, and distant reflection components in the spectrum. The absorbing column is found to be modest (∼6×10{sup 21} cm{sup −2} ), and does not introduce any significant curvature in the Fe K band. We are able to place a strong constraint on the presence of a broadened Fe Kα line (E{sub rest}=6.46{sub −0.07}{sup +0.08} keV with σ=0.33{sub −0.07}{sup +0.08} keV and EW=34{sub −7}{sup +8} eV), though we are not able to constrain any of the parameters of a relativistic reflection model. These results highlight the range in broad Fe K line strengths observed in nearby, bright, active galactic nuclei (roughly an order of magnitude), and imply a corresponding range in the physical properties of the inner accretion disk in these sources. We have also updated our previously reported measurement of the high-energy cutoff of the hard X-ray emission using both observatories rather than just NuSTAR alone: E {sub cut} = 186 ± 14 keV. This high-energy cutoff acts as a proxy for the temperature of the coronal electron plasma, enabling us to further separate this parameter from the plasma's optical depth and to update our results for these parameters as well. We derive kT=50{sub −3}{sup +6} keV with τ=2.34{sub −0.11}{sup +0.16} using a spherical geometry, kT = 61 ± 1 keV with τ = 0.68 ± 0.02 for a slab geometry, with both having an equivalent goodness-of-fit.

• OSTI ID: 22356676
• Journal Information: Astrophysical Journal, Vol. 788, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ABSORPTION
ACCRETION DISKS
EMISSION
GALAXY NUCLEI
HARD X RADIATION
KEV RANGE
PHYSICAL PROPERTIES
PLASMA
REFLECTION
RELATIVISTIC RANGE
SEYFERT GALAXIES
SPHERICAL CONFIGURATION
X-RAY GALAXIES
X-RAY SPECTRA