Determination of AGN torus morphology using X-ray spectra: A reliability study

Tathagata Saha, Alex G. Markowitz and Johannes Buchner

Several models of the X-ray reprocessing of the AGN torus have been recently released, (UXCLUMPY, CTORUS, MYTORUS etc.). These models assume a range of torus geometries and morphologies. The degeneracies in these models can limit reliable constraints of several parameters of interest, such as the intrinsic photon index and parameters of torus morphology. To investigate these effects, we simulate synthetic data under XMM-Newton and NuSTAR response files based on six different models. We use Bayesian methods to analyze the simulated datasets with the same set of models. Several geometrical parameters remain unconstrained for exposure times and fluxes typical of nearby Compton-thick AGN. In addition, a distinction of model or morphology using Bayesian methods is possible only if we have a high intrinsic value of flux for a typical exposure time. Our project aims to provide guidance for the X-ray community both in terms of the accuracy in applying the correct torus model (with implications for conclusions on the torus geometry and morphology) and the robustness of
estimation of model parameters (with implications for limitations on precision of those parameters).

Proceedings of the Polish Astronomical Society, vol. 12, 44-49 (2022)

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