Colloquium on May. 27, 2021

Understanding X-ray UFOs from Black Hole Accretion Disks in AGNs

Speaker: Keigo Fukumura (JMU)

Venue: Video Conference

Time: 09:00 AM, Thursday, May. 20, 2021

Abstract:

Blueshifted ionized absorption features are commonly seen from diverse populations of active galactic nuclei (AGNs) that host supermassive black holes (BHs). Among those outflows, ultra-fast outflows (UFOs) are known also to be ubiquitously present in X-ray spectra of many AGNs of different luminosity. Canonical AGN UFOs are typically detected in Fe K band (~6-7 keV), uniquely exhibiting highly ionized ions (log xi ~ 4-6) of massive column (NH > 1e23 cm^-2) at near-relativistic velocity (v/c > 0.1). UFOs are thought to be launched from the inner part of an accretion disk, but the current understanding of these fast outflows remains very elusive despite an extensive effort (both theoretical and observational) to date. In this presentation I will briefly introduce the general phenomenology of the observed UFOs, followed by the plausible launching mechanisms. With a special focus on magnetic driving in the context of magnetohydrodynamics (MHD), I will briefly describe the MHD disk wind model coupled to post-process photoionization calculations to perform spectral modeling of UFOs and their likely correlations implied from data. In the end, I will demonstrate microcalorimeter simulations with the prospective XRISM/Resolve and Athena/X-IFU observations for future study.

Report PPT:  SWIFAR_Keigo Fukumura.pdf