Stark broadening of the four times ionized silicon spectral lines

Nebil Ben Nessib (1) , Milan S. Dimitrijevic (2) , Sylvie Sahal-Bréchot (3)

1 Groupe de Recherche en Physique Atomique et Astrophysique, Université de Carthage
2 Belgrade Astronomical Observatory
3 LERMA - Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique

Using a semiclassical perturbation approach, we have obtained Stark broadening parameters for 16 Si V multiplets using atomic data calculated ab initio with the SUPERSTRUCTURE code. In order to complete Stark broadening data for the most important charged perturbers in stellar atmospheres, Stark broadening parameters for proton-, He II-, and Si II-impact line widths and shifts are also presented. Results have been obtained for an electron density of 10¹⁷ cm^-3 as a function of temperature. Moreover, we have performed the same calculations with oscillator strengths calculated within the Coulomb approximation. The differences, which are within the error bars of the semiclassical perturbation approach (±20-30%) confirm that the Bates & Damgaard approximation may be used to complete the atomic data set needed for the Stark broadening calculations for multicharged ions like Si V, where more reliable oscillator strength values are not available.

Domaines: Astrophysique [astro-ph]

Nebil Ben Nessib, Milan S. Dimitrijevic, Sylvie Sahal-Bréchot. Stark broadening of the four times ionized silicon spectral lines. Astronomy and Astrophysics - A&A, 2004, 423, pp.397-400. ⟨10.1051/0004-6361:20047100⟩. ⟨hal-03785130⟩