Modeling of the Lyman gamma satellites in FUSE spectra of DA white dwarfs

Abstract

We present new theoretical calculations of the line profile of Lyman gamma that include transitions in which a photon is absorbed by a neutral hydrogen atom while it interacts with a proton. Models show that two absorption features located near 992 A and 996 A are due to H-H^+ collisions. These quasi-molecular satellites are similar to those that were identified in the wings of Lyman alpha and Lyman beta lines of hydrogen-rich white dwarfs. We compute synthetic spectra that take account of these new theoretical profiles and compare them to the spectra of four DA white dwarfs that were observed with FUSE. The models predict the absorption features that are observed in the wing of Lyman gamma near 995 A, and confirm that these features are quasi-molecular satellites.

5 pages, 3 figures, accepted for publication in Astronomy and Astrophysics

References in corpus (3)

• Deuterium Toward WD1634-573: Results from the Far Ultraviolet Spectroscopic Explorer (FUSE) Mission
• FUSE observations of hot white dwarfs
• Quasi-molecular lines in Lyman wings of cool DA white dwarfs; Application to FUSE observations of G231-40

Cited by in corpus (6)

• Orbital Parameters and Chemical Composition of Four White Dwarfs in Post-Common Envelope Binaries
• Unusual Abundances from Planetary System Material Polluting the White Dwarf G238-44
• FUSE Observation of the Ultramassive White Dwarf PG1658+441
• FUSE observations of G226-29: First detection of the H_2 quasi-molecular satellite at 1150A
• Theoretical study of the line profiles of the hydrogen perturbed by collisions with protons
• Parameter-free Stark Broadening of Hydrogen Lines in DA White Dwarfs