Application of Clumpy Torus Model to Broadband X-ray Spectra of Two Seyfert 1 Galaxies: IC 4329A and NGC 7469

Abstract

We apply a new X-ray clumpy torus model called XCLUMPY (Tanimoto et al. 2019), where the clump distribution is assumed to be the same as in the infrared clumpy torus model (CLUMPY) by Nenkova et al. 2008, to the broadband X-ray spectra of type-1 active galactic nuclei (AGNs) for the first time. We analyze the archival data of IC 4329A and NGC 7469 observed with NuSTAR/Suzaku and NuSTAR/XMM-Newton, respectively, whose infrared spectra were studied with CLUMPY by Ichikawa et al. 2015 and optical extinctions ($A_{\mathrm{V}}$) of the tori were estimated. We consider two models, invoking (Model 1) a relativistic reflection component from the accretion disk and (Model 2) a partial absorber. Assuming that the narrow Fe K$\alpha$ emission line at 6.4 keV originates from the torus, we separate the contribution of the torus reflection components in the total spectra. Our models yield equatorial hydrogen column densities of the tori to be $N_{\mathrm{H}}^{\mathrm{Equ}}=$ (0.53--1.43) $\times 10^{23}\mathrm{c}{\mathrm{m}}^{-2}$ and $N_{\mathrm{H}}^{\mathrm{Equ}}=$ (0.84--1.43) $\times 10^{24}\mathrm{c}{\mathrm{m}}^{-2}$, for IC 4329A and NGC 7469, respectively. We find that the $N_{\mathrm{H}}/A_{\mathrm{V}}$ ratios in the tori are by factors of 25--68 (IC 4329A) and 2.4--3.9 (NGC 7469) smaller than that in the Galactic interstellar medium (ISM). These results suggest that a non-negligible fraction of AGNs are 'dust-rich' compared with the Galactic ISM, as opposite to the general trend previously reported in many obscured AGNs.

13 pages, 11 figures, (accepted in the Astrophysical Journal, ApJ)

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Cited by in corpus (15)

• Comprehensive Broadband X-ray and Multiwavelength Study of Active Galactic Nuclei in Local 57 Ultra/luminous Infrared Galaxies Observed with NuSTAR and/or Swift/BAT
• Systematic Study of AGN Clumpy Tori with Broadband X-ray Spectroscopy: Updated Unified Picture of AGN Structure
• NuSTAR Observations of 52 Compton-thick Active Galactic Nuclei Selected by the Swift/BAT All-sky Hard X-Ray Survey
• X-ray radiative transfer in full 3D with SKIRT
• Hard X-Ray to Radio Multiwavelength SED Analysis of Local U/LIRGs in GOALS Sample with Self-consistent AGN Model Including Polar-dust Component
• Application of X-Ray Clumpy Torus Model (XCLUMPY) to 10 Obscured Active Galactic Nuclei Observed with Suzaku and NuSTAR
• Nature of Compton-thick Active Galactic Nuclei in "Non-merging'' Luminous Infrared Galaxies UGC 2608 and NGC 5135 Revealed with Broadband X-ray Spectroscopy
• Inferring the morphology of AGN torus using X-ray spectra: A reliability study
• AstroSat/UVIT observations of IC4329A: Constraining the accretion disc inner radius
• Broadband X-ray Spectral Analysis of the Dual AGN System Mrk 739
• Revealing Thermal Comptonization of accretion-disk photons in IC4329A with AstroSat
• Origin of the complex iron line structure and spectral variation in Mrk 766
• XMM-Newton --NuSTAR monitoring campaign of the Seyfert 1 galaxy IC 4329A
• Broadband X-ray Spectral Study of Nuclear Structure in Local Obscured Radio Galaxies
• Testing X-ray Reprocessing and Mapping the Soft Excess of NGC 7469 with NICER