Stark broadening of Pb IV spectral lines of astrophysical interest

Abstract

Using a semi-empirical approach, we report in this paper calculated values of the Stark broadening parameters for 58 lines of Pb IV. They were calculated using a set of wavefunctions obtained from Hartree–Fock relativistic calculations including core polarization effects. Stark widths for 58 lines of Pb IV arising from 5d¹⁰ns (n=7,8), 5d¹⁰6p, 5d⁹6s6p, 5d¹⁰nd (n=6,7), 5d¹⁰5g and 5d¹⁰nh (n=6,7) configurations have been calculated in this way. Stark widths and shifts are presented for an electron density of 10¹⁷ cmˉ³ and temperatures T=11 000–200 000 K. These atomic data are relevant to the analysis of Pb IV detected in Far Ultraviolet Spectroscopic Explorer spectra of hot subdwarf B stars and are used to determine the lead abundance of the early B main-sequence star AV 304 in the Small Magallanic Cloud by measuring the 1313.1 Å resonance line. Common trends for the Stark width of the resonance lines have been found and are discussed.