0000000000038467
AUTHOR
B. Grabowski
Pressure Shift and Gravitational Red Shift of Balmer Lines in White Dwarfs. Rediscussion
The Stark-induced shift and asymmetry, the so-called pressure shift (PS) of $H_\alpha$ and $H_\beta$ Balmer lines in spectra of DA white dwarfs (WDs), as masking effects in measurements of the gravitational red shift in WDs, have been examined in detail. The results are compared with our earlier ones from before a quarter of a century (Grabowski et al. 1987, hereafter ApJ'87; Madej and Grabowski 1990). In these earlier papers, as a dominant constituent of the Balmer-line-profiles, the standard, symmetrical Stark line profiles, shifted as the whole by PS-effect, were applied to all spectrally active layers of the WD atmosphere. At present, in each of the WD layers, the Stark-line-profiles (e…
Stark broadening of hydrogen spectral lines with fine structure effects
Formalism and numerical code have been elaborated for calculation of hydrogen line profiles in conditions of plasma in which Stark broadening and fine energy splitting are comparable and it is not possible to neglect either of them. It corresponds to the range of electron densities $10^{11} < N_e ({\rm cm}^{-3}) < 10^{15}$ . Lamb shift and spontaneous emission effects have also been included. Computer simulation method was applied in the calculations. Final results have been compared with experimental and theoretical findings by other authors.
Perturber's charge effect on Stark broadened hydrogen lines in helium plasmas
Abstract The Stark line profiles for hydrogen Ly α , Ly β , Hα, and Hβ are calculated using the computer simulation method for helium plasmas in the range of electron concentration from 1018 to 10 19 cm −3 at increasing temperature values kT from 7 to 10 eV , according to the experimental measurements in dense plasmas (Bochum experiment). The calculation was carried out at two limiting assumptions about the perturbers: (a) in the helium plasma only singly ionized helium ions occur, and (b) in the plasma the doubly ionized ions exclusively exist. In the paper the ratio of the calculated full half-widths, FWHM(b)/FWHM(a), for these lines are presented. The ratio equals about to 1.1 for Lyβ an…