A. Chougule, N. Przybilla, M. S. Dimitrijević, V. Schaffenroth
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 CrIII 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 CrIII lines visible in HST/STIS spectra of the B3 subgiant star Iota Herculis and the subdwarf B-star Feige 66.
Keywords
Line: profiles; Stars: abundances
Spectral Line Shapes in Astrophysics and Related Topics
Drahomir Chochol, Julius Koza, Ales Kucera, Lubos Neslusan, Vladimir Porubcan, Theodor Pribulla
Astronomical Institute of the Slovak Academy of Sciences
Volume 50, Number 1, Page 139
2020 January
