Theoretical study of the Lyman $\gamma$ line profile of atomic hydrogen perturbed by collisions with protons

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 $\alpha$ and Lyman $\beta$ were previously identified in the spectra of the DA white dwarfs. We present here new theoretical calculations of Lyman $\gamma$ profiles perturbed by protons. They allow a large feature near 995 A in UV spectra of hot white dwarfs to be identified. This feature is a blend of two quasi-molecular Lyman $\gamma$ satellites due to H-H+ collisions near 992 A and 996 A.