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Journal Articles Astrophys.J. Year : 2020

A hard look at local, optically-selected, obscured Seyfert galaxies

E.S. Kammoun
  • Function : Author
J.M. Miller
  • Function : Author
M. Koss
  • Function : Author
K. Oh
  • Function : Author
A. Zoghbi
  • Function : Author
R.F. Mushotzky
  • Function : Author
E. Behar
  • Function : Author
W.N. Brandt
  • Function : Author
L.W. Brenneman
  • Function : Author
J.S. Kaastra
  • Function : Author
A.M. Lohfink
  • Function : Author
D. Proga
  • Function : Author
D. Stern


We study the X-ray spectra of a sample of 19 obscured, optically selected Seyfert galaxies (Sy 1.8, 1.9, and 2) in the local universe (d ≤ 175 Mpc), drawn from the CfA Seyfert sample. Our analysis is driven by the high sensitivity of NuSTAR in the hard X-rays, coupled with soft X-ray spectra using XMM-Newton, Chandra, Suzaku, and Swift/XRT. We also analyze the optical spectra of these sources in order to obtain accurate mass estimates and Eddington fractions. We employ four different models to analyze the X-ray spectra of these sources, which all provide consistent results. We find that 79%–90% of the sources are heavily obscured with line-of-sight column density N H > 1023 cm−2. We also find a Compton-thick (N H > 1024 cm−2) fraction of 37%–53%. These results are consistent with previous estimates based on multiwavelength analyses. We find that the fraction of reprocessed to intrinsic emission is positively correlated with N H and negatively correlated with the intrinsic, unabsorbed X-ray luminosity (in agreement with the Iwasawa–Taniguchi effect). Our results support the hypothesis that radiation pressure regulates the distribution of the circumnuclear material.

Dates and versions

hal-02908402 , version 1 (29-07-2020)



E.S. Kammoun, J.M. Miller, M. Koss, K. Oh, A. Zoghbi, et al.. A hard look at local, optically-selected, obscured Seyfert galaxies. Astrophys.J., 2020, 901 (2), pp.161. ⟨10.3847/1538-4357/abb29f⟩. ⟨hal-02908402⟩
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