Astrophysics Colloquium 10/29/19: Understanding Enigmatic Nature Of AGN Ultra-Fast Outflows In Magnetic View (speaker: Keigo Fukumura, James Madison University)

Tuesday October 29, 2019 4:00 pm

Abstract: Blueshifted ionized absorption features at near-relativistic velocities (v~0.1c or higher), known as ultra-fast outflows (UFOs), seem to be ubiquitously present in X-ray spectra of many AGN populations of different luminosity. Canonical AGN UFOs, typically detected in Fe K band, exhibit massive column (NH > 1e23 cm^-2), highly ionized ions (log \xi ~ 4 – 6) besides its high velocity. Despite an extensive effort (both theoretical and observational) to reveal the physical identity and its origin, our understanding of these outflows remains very elusive to date. I will discuss a scenario where ionized UFOs are magnetically launched from an accretion disk by the action of a global black hole magnetosphere. Utilizing semi-analytic magnetohydrodynamic (MHD) framework of disk-winds, we perform post-process photoionization calculations with xstar to model Fe XXVI UFO spectrum and its potential behavior such as correlations for different X-ray luminosity.

Host: Herman Marshall


Event Contact

Debbie Meinbresse