Stark broadening of Ca IV spectral lines of astrophysical interest

Abstract

Ca IV emission lines are under the preview of Solar Ultraviolet Measurements of Emitted Radiation device aboard the Solar and Heliospheric Observatory. Also, lines of the Ca IV in planetary nebulae NGC 7027 were detected with the Short Wavelength Spectrometer on board the Infrared Space Observatory. These facts justify an attempt to provide new spectroscopic parameters of Ca IV. There are no theoretical or experimental Stark broadening data for Ca IV. Using the Griem semi-empirical approach and the COWAN code, we report in this paper calculated values of the Stark broadening parameters for 467 lines of Ca IV. They were calculated using a set of wavefunctions obtained by using Hartree–Fock relativistic calculations. These lines arising from 3s²3p⁴ns (n=4,5), 3s²3p⁴4p, 3s²3p⁴nd (n=3,4) configurations. Stark widths and shifts are presented for an electron density of 10¹⁷ cmˉ³ and temperatures T=10 000, 20 000 and 50 200 K. As these data cannot be compared to others in the literature, we present an analysis of the different regularities of the values presented in this work.