Solución rigurosa de la ecuación de transporte en simetría esférica y campos de velocidad

Abstract

We have computed Hα line profiles in an expanding atmosphere with a chromospheric temperature structure. The radiative transfer equation has been treated rigorously in a spherically symmetric medium, applying the comoving-frame method. The simultaneous solution of the statistical equilibrium equations were carried out for a hydrogen atomic model considering 6 energy-levels plus continuum. Our calculations show that the morphological characteristics of the Hα profile - P Cygni, double-peaked or single-peaked emission - are strongly determined by the structure of the wind in the atmospheric layers close to the central star - the base of the wind and the immediate subphotospheric regions - rather than in the cool envelope. Our models indicate that the cool envelope only contributes to the global intensity of the Hα emission profile. These results provide an alternative interpretation of the Be phenomenon, in terms of the source function behaviour.