A dynamic model for the outer nebula of R Aquarii

W. J. Henney & J. E. Dyson, University of Manchester, UK

Astronomy & Astrophysics 261, 301-313

Abstract:

The symbiotic star R Aquarii is surrounded by a complex extended emission nebulosity. We model the lenticular outer nebula as the interaction of a fast wind from an accretion disk with inhomogeneously distributed ambient gas. The ambient gas is swept up into a thin shell which becomes elongated in the direction of the steepest density gradient. We investigate a variety of ambient density distributions and we show that the gross morphology, kinematics and optical appearance of the nebula can be reproduced by such a model under the assumption that the emission is produced by optically thin shock-heated gas. In the best-fit model, the ambient gas has a number density of 10 cm-3 in the orbital plane of the system and falls off exponentially above and below this plane. We deduce the mass loss rate of the fast wind to be of order 10-10 solar mass/yr for an assumed fast wind velocity of 1000 km/s, and we show this to be broadly consistent with observations.

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  • Will Henney <will@astroscu.unam.mx>
    Last modified: Tue Dec 19 16:17:35 CST 1995