X-ray Simulations of Polar Gas in Accreting Supermassive Black Holes
  Recent observations have shown that a large portion of the mid--infrared
(MIR) spectrum of active galactic nuclei (AGN) stems from the polar regions. In
this paper, we investigate the effects of this polar gas on the X-ray spectrum
of AGN using ray-tracing simulations. Two geometries for the polar gas are
considered, (1) a hollow cone corresponding to the best fit MIR model and (2) a
filled cone, both with varying column densities (ranging from
$10^{21}-10^{22.5}$ cm$^{-2}$) along with a torus surrounding the central X-ray
source. We find that the polar gas leads to an increase in the equivalent width
of several fluorescence lines below $5$ keV (e.g., O, Ne, Mg, Si). A filled
geometry is unlikely for the polar component, as the X-ray spectra of many Type
1 AGN would show signatures of obscuration. We also consider extra emission
from the narrow line region such as a scattered power-law with many
photoionised lines from obscured AGNs, and different opening angles and matter
compositions for the hollow cone. These simulations will provide a fundamental
benchmark for current and future high spectral resolution X-ray instruments,
such as those on board XRISM and Athena.
