Eur. Phys. J. D 29, 7-16 (2004)
https://doi.org/10.1140/epjd/e2004-00016-4

Theoretical study of the Lyman γ line profile of atomic hydrogen perturbed by collisions with protons

Lyman γ line profile

¹ Institut d'Astrophysique de Paris, CNRS, 98 boulevard Arago, 75014 Paris, France
² Observatoire de Paris-Meudon, LERMA, 92195 Meudon Principal Cedex, France
³ Department of Physics, University of Louisville, Louisville, KY 40292, USA
⁴ 45 Puye, Los Alamos, NM 87544, USA

Corresponding authors: ^a allard@iap.fr - ^b kielkopf@louisville.edu

Received: 1 July 2003
Published online: 17 February 2004

Abstract

The far wings of the Lyman series of atomic hydrogen exhibit satellites, enhancements that may be associated with quasi-molecular states of H₂ and H^+_2. Quasi-molecular satellites in the red wings of Lyman α and Lyman β were previously identified in the spectra of the DA white dwarfs. We present here new theoretical calculations of Lyman γ profiles perturbed by protons. They allow a large feature near 995 Å in UV spectra of hot white dwarfs to be identified. This feature is a blend of two quasi-molecular Lyman γ satellites due to H-H⁺ collisions near 992 Å and 996 Å.