Compton Shoulder Diagnostics in Active Galactic Nuclei for Probing the Metalicity of the Obscuring Compton-Thick Tori

Abstract

We analyzed the spectral shape of the Compton shoulder around the neutral Fe-K${}_{\alpha }$ line of the Compton-thick type II Seyfert nucleus of the Circinus galaxy. The characteristics of this Compton shoulder with respect to the reflected continuum and Fe-K${}_{\alpha }$ line core intensity are a powerful diagnostics tool for analyzing the structure of the molecular tori, which obscure the central engine. We applied our Monte-Carlo-based X-ray reflection spectral model to the Chandra High Energy Transmission Grating data and successfully constrained the various spectral parameters independently, using only the spectral data only around the Fe-K${}_{\alpha }$ emission line. The obtained column density and inclination angle are consistent with the previous observations and the Compton-thick type II Seyfert picture. In addition, we determined the metal abundance of the molecular torus for the case of the smooth and clumpy torus to be 1.75${}_{-0.17}^{+0.19}$ and 1.74$\pm$0.16 solar abundance, respectively. Such slightly over-solar abundance can be useful information for discussing the star formation rate in the molecular tori of active galactic nuclei.

8 pages, 3 figures, 1 table, accepted for publication in The Astrophysical Journal

References in corpus (7)

• AGN Dusty Tori: I. Handling of Clumpy Media
• Emission-line Diagnostics of Low Metallicity AGN
• Radiative Transfer Modeling of Three-Dimensional Clumpy AGN Tori and its Application to NGC 1068
• The 2-79 keV X-ray Spectrum of the Circinus Galaxy with NuSTAR, XMM-Newton and Chandra: a Fully Compton-Thick AGN
• Starbursts and torus evolution in AGN
• Sensitivity of the Fe K-alpha Compton shoulder to the geometry and variability of the X-ray illumination of cosmic objects
• Suzaku observation of the Phoenix Galaxy

Cited by in corpus (7)

• X-Ray Spectral Model from Clumpy Torus and Its Application to Circinus Galaxy
• X-ray radiative transfer in full 3D with SKIRT
• X-ray Constraint on Location of AGN Torus in Circinus Galaxy
• X-ray Simulations of Polar Gas in Accreting Supermassive Black Holes
• NuSTAR observations of a heavily X-ray obscured AGN in the dwarf galaxy J144013+024744
• Ray-tracing simulations of the Soft X-ray Scattered Emission in obscured Active Galactic Nuclei
• The FeK$\alpha$ Compton shoulder in accreting Supermassive Black Holes