Application of X-Ray Clumpy Torus Model (XCLUMPY) to 10 Obscured Active Galactic Nuclei Observed with Suzaku and NuSTAR

TL;DR

This study applies the XCLUMPY X-ray spectral model to analyze the torus structures of 10 obscured AGNs, comparing X-ray and infrared data to understand dust and gas distributions and their inclination dependence.

Contribution

It demonstrates the consistency between X-ray and infrared torus parameters using the same clumpy torus model and reveals the impact of dusty polar outflows on infrared observations.

Findings

Infrared-derived torus widths are larger than X-ray ones.

The difference in widths correlates with inclination angle.

Large scatter in dust-to-gas ratio indicates diverse circumnuclear environments.

Abstract

We apply XCLUMPY, an X-ray spectral model from a clumpy torus in an active galactic nucleus (AGN), to the broadband X-ray spectra of 10 obscured AGNs observed with both Suzaku and NuSTAR. The infrared spectra of these AGNs were analyzed with the CLUMPY code. Since XCLUMPY adopts the same clump distribution as that in the CLUMPY, we can directly compare the torus parameters obtained from the X-ray spectra and those from the infrared ones. The torus angular widths determined from the infrared spectra ($\sigma_{\mathrm{IR}}$) are systematically larger than those from the X-ray data ($\sigma_{\mathrm{X}}$); the difference ($\sigma_{\mathrm{IR}}-\sigma_{\mathrm{X}}$) correlates with the inclination angle determined from the X-ray spectrum. These results can be explained by the contribution from dusty polar outflows to the observed infrared flux, which becomes more significant at higher inclinations (more edge-on views). The ratio of the hydrogen column density and V-band extinction in the line of sight absorber shows large scatter ($\simeq$1 dex) around the Galactic value, suggesting that a significant fraction of AGNs have dust-rich circumnuclear environments.