From Static to Dynamic Views of AGN Coronae
Xiurui Zhao (Caltech)
Tuesday 29/09/2026 @ 14:00, Sala Antonio Sollima (IV piano Battiferro)
More than 80% of the extragalactic X-ray background originates from accreting supermassive black holes, known as active galactic nuclei (AGN). Their X-ray emission is primarily produced by a compact region of energetic plasma called the corona. Despite its importance, the physical properties of the corona remain poorly understood. In this talk, I will present our recent efforts to probe coronal physics using high-redshift AGN, for which cosmological redshift shifts key spectral features into the energy range where they can be more effectively constrained. I will also discuss our work using X-ray variability to study AGN coronae, which allows us to transit from a “static” picture of corona to a dynamic view of coronal evolution.