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(gzipped) PostScript## Analytical 2-D solutions for hydrodynamic, thermally and radiatively driven, astrophysical outflows. Applications to B stars
In this work, we deal with the two-dimensional problem of steady
plasma outflow from rotating central astrophysical gravitational
objects. Considering the stellar atmosphere optically thin and the
radiative force (due to the central object's luminosity) radial, we
obtain fully analytical solutions for thermally and radiatively
driven outflows. The flow is helicoidal and axisymmetric and the
plasma inviscid and non-polytropic. First, we generalize the
Kakouris & Moussas 1996 solution imposing a generalized geometry in
the flow velocity which implies differential fluid rotation. The
solutions are of four types with velocity maxima either along the
equator or along the polar axis of the central body. The dependence
of the solutions upon the radial distance The incorporation of the radiative force in the hydrodynamic equations is very important in massive winds of early and late type main sequence stars and evolved giants and supergiants. We present analytical 2-D solutions for thermally plus radiatively driven stellar winds and we apply one kind of them to B5I type supergiants in order to understand the observed winds of these stars under a thermal (coronal) plus a radiative mechanism of ejecting stellar plasma in the interstellar medium. Maximum outflow velocities and mass loss rates, close to the observed, are easily obtained.
© European Southern Observatory (ESO) 1997 |