Sr v–vi line widths in hot white dwarf atmospheres

Abstract

Missing Stark widths for 37 spectral lines of strontium ions (17 Sr V lines and 20 Sr VI lines) have been calculated using a quantum mechanical method. 23 spectral lines of Sr V have been recently discovered, for the first time, in the Ultraviolet (UV) spectrum of the hot white dwarf RE 0503−289. This recent discovery prompts us to calculate the Stark widths of the new lines. These calculations can fill the lack of the database STARK-B and can be used to investigate the observed spectra in such stars. To perform the line broadening calculations, preliminary structure and collision calculations have been carried out using the sequence of the University College London (UCL) codes (superstructure (sst), distorted wave (dw), jajom). Results for the 37 lines are provided for different electron temperatures and at density Ne = 1017 cm−3. The present results will enter the STARK-B data base which is a node of the Virtual Atomic and Molecular Data Center - VAMDC. We hope that the obtained results will be useful for the non-local thermodynamic equilibrium (NLTE) modelling of stellar-atmosphere.

Quantum mechanical line widths of ionized oxygen, silicon, and aluminium; comparisons with recent experimental results

“…The MSE values have been taken from the database STARK-B (Sahal-Bréchot et al 2022). Our quantum results are overestimated compared to the experimental ones for almost all the considered lines.…”

“…We hope that the new quantum Stark widths could be of interest in stellar-atmosphere modelling, and could be used with confidence in plasma diagnostic. The obtained quantum results will be implemented to the database STARK-B (Sahal-Bréchot et al 2022). As it was recommended in Gavanski et al (2016), new experiments and calculations for the considered lines are welcome to reach a conclusion, especially for the Al III ion for which we found only one experiment.…”

“…Using this relation, we could predict the considered line widths for all the Ne-like ions between Mg III and Br XXVI. Our method has been also used to provide new Stark broadening data requested for astrophysical applications (Elabidi 2021b;Sahal-Bréchot & Elabidi 2021;Aloui et al 2022). In each line broadening calculations, we always evaluate the atomic data used in that calculations to ensure an acceptable accuracy of the results.…”

“…Besides the spectral analysis (synthesis, analysis, and interpretation of stellar spectra), Stark broadening parameters are required for investigations of radiative transfer through stellar atmospheres; determination of chemical abundances; modelling and investigation of subphotospheric layers. They are also used to investigate the importance of Stark broadening mechanism in plasma conditions of hot DO white dwarfs compared to the Doppler one (Aloui et al 2022;Sahal-Bréchot & Elabidi 2021). In laboratory plasma applications, Stark broadening data are used in laboratory plasma diagnostics, laser produced plasma and inertial fusion plasma investigation and modelling, the investigations of lasers, and in the research of different technological plasmas, such as those used in laser welding and piercing, as well as for light sources.…”

Data for Photodissociation of Some Small Molecular Ions Relevant for Astrochemistry and Laboratory Investigation

“…Atomic and molecular databases and data have become crucial for data interpretation, diagnostics, and the creation of models and simulations of intricate physical processes [1][2][3][4]. The importance of studying optical properties in different fields, especially when modelling those systems, is of particular interest [5][6][7]. If the required data, i.e., information, are available, we can simulate the spectral properties [8][9][10][11].…”