Resolving the AGN Torus Spectrally, Spatially, and Temporally

NuSTAR observations of obscured AGN in the local universe enable basic structural parameters of the obscuring torus, such as the covering factor and the globally averaged column density, to be observationally constrained from the X-ray band. We have recently completed an analysis of these parameters in a large sample of 140 obscured AGN selected from the Swift/BAT catalog and observed simultaneously with NuSTAR and Swift. However, detailed analyses of particular AGN reveal that parameters of simple torus models may depend on the choice of the fitting model and its nuisance parameters, variability in intrinsic luminosity or line-of-sight column density, and contamination from non-nuclear emission. In modeling spatially unresolved single-epoch AGN spectra, these effects can be sources of systematic uncertainties that exceed statistical uncertainties on important structural parameters of the accretion flow. Using novel spectral models and archival data for nearby AGN, I will demonstrate how broadband X-ray spectroscopy (0.5-200 keV) can be self-consistently combined with spatially resolved and multi-epoch X-ray data in order to obtain more robust constraints. Together with the future ability to probe velocity structures with high-resolution X-ray data, this will help us to better understand the complex AGN structure widely known under the deceptively simple name of the torus.