Mar 10, 2021

Speaker: Dr. Demos Kazanas (NASA/GFSC)

Title: AGN Warm Absorbers: The Rosetta Stone of AGN phenomenology?

Abstract: Warm Absorbers are blue shifted absorption features in the AGN X-ray spectra, the result of outflows photoionized by the AGN continuum. They span a wide range of ionization parameter, a feature that allows one to estimate their density profiles along the observer's line of sight. These are found to be quite shallow and extending over many decades in radius, inconsistent with radiation or thermally driven outflows, but consistent with magnetohydrodynamic ones launched across the entire accretion disk domain. It is shown that the corresponding wind mass flux increases with radius, a fact that affects crucially the dynamics of accretion. It is concluded that under these conditions, the global accretion rate is the parameter that determines the luminosity ratio of the Big Blue Bump to that of the hard X-ray emission, and as such determine the AGN structure in the black hole vicinity along with a host of phenomenology details. It is further proposed that similar structures are present in radio loud AGN too and they are crucial in the determination of their global phenomenology, usually referred to as "the Blazar Sequence".