Eur. Phys. J. D 44, 507-514 (2007)
https://doi.org/10.1140/epjd/e2007-00230-6

Impact broadening of alkali lines in brown dwarfs

¹ Institut d'Astrophysique de Paris, UMR 7095, CNRS, Université Pierre et Marie Curie, 98bis boulevard Arago, 75014 Paris, France
² Observatoire de Paris-Meudon, LERMA, UMR 8112, CNRS, 92195 Meudon Principal Cedex, France
³ Department of Physics and Astronomy, University of Louisville, Louisville, KY, 40292, USA
⁴ Centre de Recherche Astronomique de Lyon, UMR 5574, CNRS, Université de Lyon, École Normale Supérieure de Lyon, 46 allée d'Italie, 69634 Lyon, France

Corresponding authors: ^a allard@iap.fr - ^b kielkopf@louisville.edu - ^c fallard@ens-lyon.fr

Received: 1 April 2007
Revised: 8 June 2007
Published online: 4 July 2007

Abstract

Spectral line widths of the light alkalies are presented for conditions prevailing in brown dwarf atmospheres. A unified line shape theory and a set of pseudopotentials are used to compute widths of Li, Na, and K resonance lines perturbed by He and H₂. While limited available experimental data confirm the trends found in the theoretical values reported here, they suggest that improved potentials are needed.