scholarly journals Stark Broadening of Co II Lines in Stellar Atmospheres

Data ◽  
2020 ◽  
Vol 5 (3) ◽  
pp. 74
Author(s):  
Zlatko Majlinger ◽  
Milan S. Dimitrijević ◽  
Vladimir A. Srećković
Keyword(s):  
Spectral Line ◽  
Effective Temperature ◽  
White Dwarf ◽  
Semiempirical Method ◽  
Stellar Atmospheres ◽  
Spectral Lines ◽  
Surface Gravity ◽  
Type Star ◽  
Half Maximum ◽  
Stark Broadening

Data for Stark full widths at half maximum for 46 Co II multiplets were calculated using a modified semiempirical method. In order to show the applicability and usefulness of this set of data for research into white dwarf and A type star atmospheres, the obtained results were used to investigate the significance of the Stark broadening mechanism for Co II lines in the atmospheres of these objects. We examined the influence of surface gravity (log g), effective temperature and the wavelength of the spectral line on the importance of the inclusion of Stark broadening contribution in the profiles of the considered Co II spectral lines, for plasma conditions in atmospheric layers corresponding to different optical depths.

scholarly journals 14. White Dwarf Atmospheres

1971 ◽  
Vol 42 ◽  
pp. 81-96 ◽  
Author(s):  
V. Weidemann
Keyword(s):  
Chemical Composition ◽  
Observational Data ◽  
Effective Temperature ◽  
White Dwarf ◽  
General Information ◽  
Stellar Atmospheres ◽  
Surface Gravity ◽  
Atmospheric Parameters

We first consider the general information scheme for the interpretation of observational data (Figure 1). From the relations plotted it is evident that (in going from left to right) this scheme can only be solved if distances are known and if we are able to determine the atmospheric parameters: effective temperature, Teff, surface gravity, g, and chemical composition from observations of colors and spectra – which is the genuine task of the theory of stellar atmospheres.

Stark broadening of Co ii spectral lines in hot stars and white dwarf spectra

2020 ◽  
Vol 496 (4) ◽  
pp. 5584-5590 ◽  
Author(s):  
Zlatko Majlinger ◽  
Milan S Dimitrijević ◽  
Vladimir A Srećković
Keyword(s):  
White Dwarf ◽  
Empirical Method ◽  
Spectral Lines ◽  
Half Maximum ◽  
Stark Broadening ◽  
Hot Stars ◽  
Approximate Methods ◽  
Semi Empirical ◽  
Stark Width

ABSTRACT Stark full widths at half-maximum for 46 Co ii multiplets have been calculated using modified semi-empirical method. The obtained results have been used to demonstrate the importance of Stark broadening mechanism in DA and DB white dwarf and A star atmospheres. With the obtained results we also test possibility of using some approximate methods of Stark width calculations developed on the basis of regularities and systematic trends.

scholarly journals ON THE STARK BROADENING OF Ru III SPECTRAL LINES

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Milan S. Dimitrijević
Keyword(s):  
Electron Density ◽  
Semiempirical Method ◽  
Spectral Lines ◽  
Half Maximum ◽  
Stark Broadening ◽  
Temperature Range ◽  
And Shifts ◽  
Doubly Charged ◽  
Stark Width

Stark broadening parameters, full widths at half maximum (FWHM) and shifts for spectral lines within six multiplets of doubly charged ruthenium ions have been calculated, for an electron density of 1017 cm-3 and temperature range from 10 000 K to 160 000 K. Calculations have been performed with the simplified modified semiempirical (SMSE) approach. In the case of two multiplets, it is possible to apply the full modified semiempirical method. The corresponding calculations have been performed and results are compared in order to test and determine the accuracy of the SMSE approach. The results are also used for the consideration of Stark width and shift regularities in Ru III spectrum.

scholarly journals Some Properties of Hot, High-Gravity, Pure Helium Atmospheres

1979 ◽  
Vol 53 ◽  
pp. 125-129
Author(s):  
F. Wesemael ◽  
H.M. Van Horn
Keyword(s):  
Effective Temperature ◽  
White Dwarf ◽  
White Dwarfs ◽  
Model Atmosphere ◽  
Surface Gravity ◽  
High Gravity ◽  
Pure Helium

Model atmosphere analyses of white dwarf spectra have contributed significantly to our understanding of the properties of degenerate stars.: In particular, the pioneering investigations of Bues (1970), Strittmatter and Wickramasinghe (1971) and Shipman (1972) have provided the first reliable determinations of the effective temperature and surface gravity of these objects (see Shipman 1979 and Weidemann 1978 for recent results). We now know with certainty that the hydrogen-rich white dwarf sequence extends at least over the range Te ∽ 6000 – 60.000K. In contrast, the hottest identified helium-rich white dwarfs seem to reach Te ~ 25.000K only, a puzzling result since the progenitors of DB white dwarfs should presumably also be helium-rich.

scholarly journals The effect of hyperfine splitting on Stark broadening for three blue-green Cu i lines in laser-induced plasma

2019 ◽  
Vol 488 (4) ◽  
pp. 5594-5603 ◽  
Author(s):  
A M Popov ◽  
N I Sushkov ◽  
S M Zaytsev ◽  
T A Labutin
Keyword(s):  
Hyperfine Splitting ◽  
Stark Effect ◽  
Stellar Atmospheres ◽  
Spectral Lines ◽  
Stark Broadening ◽  
Laser Induced Plasma ◽  
Radiation Sources ◽  
And Shifts ◽  
First Time ◽  
Existing Data

ABSTRACT Stark effect is observed in many natural and artificial plasmas and is of great importance for diagnostic purposes. Since this effect alters profiles of spectral lines, it should be taken into account when assessing chemical composition of radiation sources, including stars. Copper is one of the elements which studies of stellar atmospheres deal with. To this end, UV and visible Cu lines are used. However, there is a lack of agreement between existing data on their Stark parameters. It is therefore of interest to obtain new experimental data on these lines and to compare them to previous results. In this work, we have estimated Stark widths and shifts for three blue-green lines at 5105.54, 5153.24, and 5218.20 Å (corresponding transitions are [3d104p] 2P° → [3d94s2] 2D and [3d104d] 2D → [3d104p] 2P°) observed in a ‘long-spark’ laser-induced plasma. For the first time, we have accurately estimated an impact of hyperfine splitting on the profile shapes of the studied lines taking also into account the isotope shifts. We have shown that both effects considerably influence shift and width of Cu i line at 5105.54 Å, and shifts of Cu i lines at 5153.24 and 5218.20 Å.

The electron-impact broadening of the Nb iii for 5p–5d transitions

2019 ◽  
Vol 491 (3) ◽  
pp. 4382-4386
Author(s):  
Zoran Simić ◽  
Nenad M Sakan
Keyword(s):  
Rare Earth ◽  
Electron Impact ◽  
Rare Earth Element ◽  
Earth Element ◽  
Empirical Method ◽  
Spectral Lines ◽  
Type Star ◽  
Stark Broadening ◽  
Hot Stars ◽  
Semi Empirical

ABSTRACT In this work, we present the data of Stark widths of rare-earth element Nb iii, calculated for 21 spectral lines by using the modified semi-empirical method. Obtained results have been used to study the influence of Stark broadening on spectral lines in hot stars atmospheres such as A-type star and DA and DB white dwarfs.

scholarly journals On the stark broadening of Os II spectral lines

2020 ◽  
Vol 10 (2) ◽  
pp. 65-70
Author(s):  
Milan Dimitrijević
Keyword(s):  
Electron Density ◽  
Spectral Lines ◽  
Half Maximum ◽  
Stark Broadening ◽  
Plasma Parameters ◽  
And Shifts

Stark broadening parameters, full widths at half maximum (FWHM) and shifts for 13 Os II lines have been calculated. The plasma parameters are: electron density of 1017 cm-3 and temperatures from 5 000 K to 80 000 K. Calculations have been performed with the simplified modified semiempirical (SMSE) approach. The results are also used for the consideration of Strak width and shift regularities within the Os II 6s6D-6p6Do multiplet.

scholarly journals Stark broadening of resonant Cr II 3d5–3d44p spectral lines in hot stellar atmospheres

2013 ◽  
Vol 432 (3) ◽  
pp. 2247-2251 ◽  
Author(s):  
Z. Simić ◽  
M. S. Dimitrijević ◽  
S. Sahal-Bréchot
Keyword(s):  
Stellar Atmospheres ◽  
Spectral Lines ◽  
Stark Broadening

scholarly journals Theoretical transition probabilities, radiative lifetimes and Stark broadening parameters of singly ionized magnesium

2019 ◽  
Vol 490 (2) ◽  
pp. 1734-1737
Author(s):  
C Moreno-Díaz ◽  
A Alonso-Medina
Keyword(s):  
Transition Probabilities ◽  
Principal Quantum Number ◽  
Stellar Atmospheres ◽  
Spectral Lines ◽  
Atomic Data ◽  
Stark Broadening ◽  
Asymptotic Dependence ◽  
Radiative Lifetimes ◽  
Ionized Magnesium ◽  
Effective Principal

ABSTRACT The presence of spectral lines of singly ionized magnesium (Mg ii) in stellar atmospheres has been reported in different stars. Recently, the low-resolution spectrum obtained from Supernova 2014 J in M82, in which Mg ii absorption lines centred on 4400 Å as well as 7600 Å stand out, has been analysed. This is the motive for the atomic data calculations in this work, which are of much interest in the astrophysical area. In this article, ab initio relativistic Hartree–Fock calculations in an intermediate coupling formalism using Cowan’s code allowed us to obtain the required transition probabilities to calculate the theoretical radiative lifetimes for excited nS−, nP−, nD− and nF− states of singly ionized magnesium. An asymptotic dependence of lifetime (τnl) on the effective principal quantum number (n*) has been determined. Also, the Griem semi-empirical approach was used to obtain the theoretical Stark parameters (width and shift) of spectral lines; these data are displayed for an electron density of 1017 cm−3 and temperatures T = 10–100 (×103 K). We have compared the results of lifetimes for 16 levels and Stark parameters for seven spectral lines with previously reported experiments available in the literature. Finally, we discuss the behaviour of the Stark parameters versus temperature for three relevant spectral lines (2802.70, 2797.99 and 7868.04 Å).

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