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The origin and development of instabilities in radiatively-driven stellar winds

Description: The numerous observational indicators of instability in the radiatively-driven winds of hot stars are review briefly, followed by a summary of the present theoretical understanding of the linear instability of such winds. This provides the motivation for the hydrodynamic simulation, the major thrust of the paper. A serious approximation that must be made in order to reduce the cost of the simulations to a reasonable level--the absorption approximation for the radiation force--is discussed in so… more
Date: November 20, 1990
Creator: Castor, John I.
Partner: UNT Libraries Government Documents Department
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Time-Dependent Two-Dimensional Radiation Hydrodynamics of Accreting Matter Onto Highly Magnetized Neutron Stars

Description: We present for the first time, the self-consistent solution of the two-dimensional, time-dependent equations of radiation-hydrodynamics governing the accretion of matter onto the highly magnetized polar caps of luminous x-ray pulsars. The calculations show a structure in the accretion column very different from previous one-zone uniform models. We have included all the relevant magnetic field corrections to both the hydrodynamics and the radiative transport. We include a new theory for the diff… more
Date: November 20, 1990
Creator: Klein, R.I. (California Univ., Berkeley, CA (USA). Dept. of Astronomy Lawrence Livermore National Lab., CA (USA)) & Arons, J. (California Univ., Berkeley, CA (USA). Dept. of Astronomy California Univ., Berkeley, CA (USA). Dept. of Physics)
Partner: UNT Libraries Government Documents Department
open access

2-D Axisymmetric Line Transport

Description: The methods used in the ALTAIR code for computing the transfer of spectral line radiation in two-dimensional axially-symmetric geometry are described. ALTAIR uses a variable-Eddington-tensor approach, in which the transfer equation of non-coherent line scattering is written in moment form, and the moments are closed with an assumed tensor relating the monochromatic pressure tensor and energy density; this Eddington tensor is obtained self-consistently using an accurate angle-dependent solution … more
Date: November 20, 1990
Creator: Castor, John I.; Dykema, Pieter G. & Klein, Richard I.
Partner: UNT Libraries Government Documents Department
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