Magnetohydrodynamic DiscWinds and LineWidth Distributions.II

TL;DR

This paper models AGN emission line profiles using magnetohydrodynamic disc-wind theories, exploring how central object properties influence line-width distributions and torus geometry, with implications for understanding AGN structure.

Contribution

It extends previous MHD wind models to different AGN masses and luminosities, linking line-width dispersions to torus geometry constraints.

Findings

Linewidth dispersions constrain torus half-opening angles.

Results show mild dependence on the angular momentum parameter.

Model predictions align with observational upper limits.

Abstract

We study AGN emission line profiles combining an improved version of the accretion disc-wind model of Murray & Chiang with the magneto-hydrodynamic model of Emmering et al. (1992). Here we extend our previous work to consider central objects with different masses and/or luminosities. We have compared the dispersions in our model C IV linewidth distributions to observational upper limit on that dispersion, considering both smooth and clumpy torus models. Following Fine et al., we transform that scatter in the profile line-widths into a constraint on the torus geometry and show how the half-opening angle of the obscuring structure depends on the mass of the central object and the accretion rate. We find that the results depend only mildly on the dimensionless angular momentum, one of the two integrals of motion that characterise the dynamics of the self-similar ideal MHD outflows