English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

We extend our modeling of the ionization structure of magnetohydrodynamic(MHD) accretion-disk winds, previously applied to Seyfert galaxies, to apopulation of quasi-stellar-objects (QSOs) of much lower X-ray-to-UV fluxratios, i.e. smaller $\alpha_{\rm ox}$ index, motivated by UV/X-ray ionizedabsorbers with extremely high outflow velocities in UV-luminous QSOs. Wedemonstrate that magnetically-driven winds ionized by a spectrum with$\alpha_{\rm ox} \simeq -2$ can produce the charge states responsible for \civ~and \fexxv/\fexxvi ~absorption in wind regions with corresponding maximumvelocities of $v$(\civ) $\lsim 0.1c$ and $v({\rm \fexxv}) \lsim 0.6 c$ (where$c$ is the speed of light) and column densities $N_H \sim 10^{23}-10^{24}$cm$^{-2}$, in general agreement with observations. In contrast to theconventional radiation-driven wind models, {\it high-velocity flows are alwayspresent in our MHD-driven winds} but manifest in the absorption spectra onlyfor $\alpha_{\rm ox} \lsim -2$, as larger $\alpha_{\rm ox}$ values ionize thewind completely out to radii too large to demonstrate the presence of thesehigh velocities. We thus predict increasing velocities of these ionizedabsorbers with decreasing (steeper) $\alpha_{\rm ox}$, a quantity that emergesas the defining parameter in the kinematics of the AGN UV/X-ray absorbers.

Modeling High-Velocity QSO Absorbers with Photoionized MHD Disk-Winds