# X-Ray Spectral Model from Clumpy Torus and Its Application to Circinus Galaxy

## TL;DR

This paper introduces XCLUMPY, a new X-ray spectral model for clumpy tori in AGNs, validated with data from the Circinus galaxy, improving understanding of the torus structure and X-ray emission.

## Contribution

The paper develops XCLUMPY, a novel Monte Carlo based spectral model for clumpy AGN tori, and demonstrates its effectiveness with real observational data from the Circinus galaxy.

## Key findings

- XCLUMPY accurately reproduces the observed X-ray spectra of Circinus.
- The model estimates the torus parameters: high hydrogen column density and narrow angular width.
- Results are consistent with multi-wavelength observations of the galaxy.

## Abstract

We construct an X-ray spectral model from the clumpy torus in an active galactic nucleus (AGN), designated as "XCLUMPY", utilizing the Monte Carlo simulation for Astrophysics and Cosmology framework (MONACO: Odaka et al. 2011, 2016). The adopted geometry of the torus is the same as that in Nenkova et al. (2008), who assume a power law distribution of clumps in the radial direction and a normal distribution in the elevation direction. We investigate the dependence of the X-ray continuum and Fe K$\alpha$ fluorescence line profile on the torus parameters. Our model is compared with other torus models: MYTorus model (Murphy & Yaqoob 2009), Ikeda model (Ikeda et al. 2009), and CTorus model (Liu & Li 2014). As an example, we also present the results applied to the broadband X-ray spectra of the Circinus galaxy observed with XMM-Newton, Suzaku, and NuSTAR. Our model can well reproduce the data, yielding a hydrogen column density along the equatorial plane $N_{\mathrm{H}}^{\mathrm{Equ}} = 9.08_{-0.08}^{+0.14} \times 10^{24}$ cm$^{-2}$, a torus angular width $\sigma = 14.7_{-0.39}^{+0.44}$ degree, and a 2--10 keV luminosity $\log L_{2-10}/\mathrm{erg \ s^{-1}} = 42.8$. These results are discussed in comparison with the observations in other wavelengths.