Eur. Phys. J. D 12, 263-268 (2000)
https://doi.org/10.1007/s100530070021

A collision-induced satellite in the Lyman β profile due to H-H collisions

Lyman β satellites

¹ Observatoire de Paris-Meudon, Département Atomes et Molécules en Astrophysique, 92195 Meudon Principal Cedex, France
² CNRS, Institut d'Astrophysique, 98bis boulevard Arago, 75014 Paris, France
³ Department of Physics, University of Louisville, Louisville, Ky 40292, USA
⁴ Institut für Physikalische Chemie, Universität Heidelberg, Im Neuenheimer Feld 229, 69120 Heidelberg, Germany

Received: 15 January 2000
Revised: 17 May 2000
Published online: 15 November 2000

Abstract

We present a theoretical profile of the Lyman β line of atomic hydrogen perturbed by collisions with neutral hydrogen atoms and protons. We use a general unified theory in which the electric dipole moment varies during a collision. A collision-induced satellite appears on Lyman β, correlated to the asymptotically forbidden transition of H₂. As a consequence, the appearance of the line wing between Lyman α and Lyman β is shown to be sensitive to the relative abundance of hydrogen ions and neutral atoms, and thereby to provide a temperature diagnostic for stellar atmospheres and laboratory plasmas.