Speaker
Description
I will discuss the current paradigm for the innermost regions of black hole accretion flows in light of constraints from X-ray spectroscopy. The main spectral components observed in luminous accretion states will be outlined, highlighting how their modeling has led to a broad picture of the radiative and dynamical processes operating in the vicinity of the black hole horizon. Despite this progress, some fundamental properties remain uncertain, reflecting the intrinsic complexity of spectral decomposition. I will critically address the ongoing discussion on the estimation of black hole spin, as well as the geometry and spatial extent of the primary emitting and reprocessing regions within the accretion flow. Finally, I will address how polarimetric measurements provide additional constraints, opening new possibilities for refining theoretical models.