Abstract

In this paper, we show that if the broad-line region clouds are in approximate energy equipartition between the magnetic field and gravity, as hypothesized by Rees, there will be a significant effect on the shape and smoothness of broad emission-line profiles in active galactic nuclei. Linewidths of contributing clouds or flow elements are much wider than their thermal widths, because of the presence of non-dissipative magnetohydrodynamic waves and their collective contribution produce emission-line profiles broader and smoother than would be expected if a magnetic field were not present. As an illustration, a simple model of isotropically emitting clouds, normally distributed in velocity, is used to show that smoothness can be achieved for less than ∼8×104 clouds and may even be as low as a few hundred. We conclude that magnetic confinement has far-reaching consequences for observing and modelling active galactic nuclei.

Document Type

Article

Publication Date

2000

Notes/Citation Information

Published in Monthly Notices of the Royal Astronomical Society, v. 316, issue 1, p. 103-106.

This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2000 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.

The copyright holder has granted the permission for posting the article here.

Digital Object Identifier (DOI)

http://dx.doi.org/10.1046/j.1365-8711.2000.03465.x

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