Document Type

Article

Publication Date

10-1-2018

Publication Title

Monthly Notices of the Royal Astronomical Society

Volume

481

Issue

4

First page number:

5263

Last page number:

5269

Abstract

We study temporal variability of radiation-driven winds using one-dimensional, time-dependent simulations and an extension of the classic theory of line-driven winds developed by Castor Abbott & Klein. We drive the wind with a sinusoidally varying radiation field and find that after a relaxation time, determined by the propagation time for waves to move out of the acceleration zone of the wind, the solution settles into a periodic state. Winds driven at frequencies much higher than the dynamical frequency behave like stationary winds with time averaged radiation flux, whereas winds driven at much lower frequencies oscillate between the high and low flux stationary states. Most interestingly, we find a resonance frequency near the dynamical frequency that results in velocity being enhanced or suppressed by a factor comparable to the amplitude of the flux variation. Whether the velocity is enhanced or suppressed depends on the relative phase between the radiation and the dynamical variables. These results suggest that a time-varying radiation source can induce density and velocity perturbations in the acceleration zones of line-driven winds.

Keywords

Hydrodynamics; Stars: Massive; Stars: Winds; Outflows; Quasars: General; X-rays: Galaxies

Disciplines

Astrophysics and Astronomy

File Format

PDF

File Size

462 Kb

Language

English

Comments

This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2018 [owner as specified on the article] Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.

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