Active galactic nuclei (AGN) are among the most powerful laboratories for studying black hole accretion and high-energy physics. While the unified model envisions a complex structure composed of a supermassive black hole (SMBH), accretion disk, X-ray emitting corona, broad- and narrow-line regions, and an obscuring dusty torus, most of these components lie on scales far too small to be directly resolved. In this talk, I will show how X-ray observations can be used to probe these otherwise difficult to access regions, with a focus on the physics of the AGN corona, accretion disk, and extended torus. Leveraging the largest hard X-ray data set assembled to date, comprising over 1000 hours of observations, we have for the first time systematically constrained the physical properties of both the corona and dusty torus across a large AGN sample. I will also present new efforts to combine submillimeter observations from ALMA with X-ray measurements, opening a novel multiwavelength window on AGN coronae and offering fresh insight into the physics of supermassive black hole (SMBH) accretion.
