Stark Broadening of Cr III Spectral Lines: DO White Dwarfs

Abstract

Abstract:Using the modified semiempirical method of Dimitrijević and Konjević, Stark widths have been calculated for six Cr III transitions, for an electron density of 10 17 cm −3 and for temperatures from 5000-80,000 K. Results have been used for the investigation of the influence of Stark broadening on spectral lines in cool DO white dwarf atmospheres. Calculated Stark widths will be implemented in the STARK-B database, which is also a part of the Virtual Atomic and Molecular Data Center (VAMDC).

The impact of improved Stark-broadening widths on the modeling of double-ionized chromium lines in hot stars

“…We study and compare the effects of improved Stark broadening tables for Cr iii lines (Dimitrijević & Chougule, 2018) and approximate Stark broadening constants as described in Castelli (2005) on the calculation of synthetic stellar spectra. We also compare these spectra with observations, for the B3 subgiant star Iota Herculis and the subdwarf B-star Feige 66.…”

“…The improved Stark broadening data of Dimitrijević & Chougule (2018) were calculated using the Modified Semi-empirical (MSE) approach (Dimitrijević & Konjević, 1980;Dimitrijević & Kršljanin, 1986;Dimitrijević & Popović, 2001). The accuracy of the MSE approach is estimated to be about ±50% in general (Dimitrijević & Popović, 2001) and it has been tested on numerous occasions (Dimitrijević, 1990).…”

Spectral Line Shapes in Plasmas II

“…However, the Stark broadening of only a minor part of all the lines observed has been calculated. Dimitrijević and Chougule [14] continue filling the gaps by providing Stark-broadening parameters of several Cr III transitions.…”

On the Stark broadening of some Cr II spectral lines in plasma

“…Chromium in various ionization stages has been observed in the spectra of white dwarf atmospheres, where the Stark broadening is usually dominant broadening mechanism, especially in deeper atmospheric layers (Simić et al, 2006;Hamdi et al, 2008;Dufour et al, 2011;Hamdi et al, 2014;Dimitrijević and Chougule, 2018). In order to determine chromium abundance in such stars, as well as for opacity calculations and more sophysticated stellar atmosphere modeling, we need the corresponding Stark broadening data.…”