CAOSP abstracts, Volume: 50, No.: 1, year: 2020

Author(s): Chougule, A.; Przybilla, N.; Dimitrijević, M.S.; Schaffenroth, V.
Journal: Contributions of the Astronomical Observatory Skalnaté Pleso, vol. 50, no. 1, p. 139-146.
Date: 1/2020
Title: The impact of improved Stark-broadening widths on the modeling of double-ionized chromium lines in hot stars
Keyword(s): Line: profiles, Stars: abundances
Pages: 139 -- 146
DOI: https://doi.org/10.31577/caosp.2020.50.1.139
NASA ADS Abstract Service: 2020CoSka..50..139C
Citation:
License: This work is licensed under a Creative Commons Attribution 4.0 International License

Abstract: Stellar atmosphere modeling and chemical abundance determinations require the knowledge of spectral line shapes. Spectral lines of chromium in various ionization stages are common in stellar spectra but detailed data on Stark broadening for them is scarce. Recently we reported on the first calculations of Stark widths for several 4s-4p transitions of double-ionized chromium, employing the Modified Semi-Empirical approach (MSE). In this work we present applications of the data to spectrum synthesis of Cr_III lines in the ultraviolet region of hot stars. The Atlas9 model atmosphere code and the line-formation code Surface were used with the assumption of local thermodynamic equilibrium. The improvements of adopting the MSE broadening tables instead of approximate Stark broadening coefficients are investigated for a total of 56 Cr_III lines visible in HST/STIS spectra of the B3 subgiant star Iota Herculis and the subdwarf B-star Feige 66.