New study of the quasi-molecular Lyman alpha satellites due to H-H and H-H(+) collisions
Gerbaldi, M.; Allard, N. F.; Kielkopf, J.; Drira, I.; Spielfiedel, A.
France, United States
Abstract
We present new theoretical calculations of the total profile of the atomic hydrogen Lyman alpha spectral line perturbed by collisions with neutral hydrogen atoms and protons. The variation of the radiative dipole moment during the collision is taken into account. This leads to an increase in the amplitude of the main spectral line satellites and to a quantitative improvement of the synthetic spectra of lambda Bootis stars compared to IUE observations.