Quantum Stark widths of N IV-V and O IV spectral lines

Abstract

In this paper, we report new quantum Full Widths at Half Maximum (FWHM) intensities for 24 spectral lines corresponding to various nitrogen and oxygen ions, including 13 N IV, 4 N V and 7 O IV lines. The majority of the spectral lines examined were recently identified in the CASPEC and UVES spectra of the O(He) star JL9, which is a hot hydrogen-deficient pre-white dwarf (pre-WD). These recent findings motivate us to compute their Stark widths in order to address the gaps in the STARK-B database. Part of the present quantum results are compared to the available theoretical and experimental data. Our quantum method, which was developed years ago and has consistently yielded reliable results compared to other approaches, can serve as a valuable tool to clarify the discrepancies observed for certain spectral lines. Additionally, the results obtained can be applied to determine elemental abundances, calculate stellar opacity, interpret and model stellar spectra, analyze observed spectra in such stars, estimate radiative transfer through stellar plasmas, and more. A portion of the current results will also be incorporated into the STARK-B database of Stark broadening parameters. Prior to evaluating the Stark widths, two computational steps were performed: first, the atomic structure was calculated, followed by the electron–ion collision calculations. We present our results for these spectral lines at various temperatures and densities.