The Role of Gamma-Ray Cascading in Supermassive Black Hole Coronae Spectra

Motivated by recent neutrino observations from NGC 1068 that exceed the corresponding gamma-ray flux, we investigate the role of gamma-ray cascading in obscuring high-energy photons in the coronae of supermassive black holes. Magnetic reconnection and turbulence energize protons, leading to gamma-ray production through photomeson interactions. These gamma rays can interact with coronal ultraviolet and X-ray photons, initiating cascades of photons and particles of lower energies. Using a Monte Carlo framework, we numerically model pair production, pair annihilation, and pair propagation in mildly relativistic plasma to quantify the effect of gamma-ray cascading on characteristics of radiation spectra. The results of our study provide insights into the underlying mechanisms responsible for the attenuated gamma-ray spectra and potential pair loading of black hole coronae.