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Non-stationary processes in the atmospheres of early-type stars:influence on the forbidden-to-intercombination line intensity ratio

Abstract

The results of kinetic equilibrium modeling for highly ionized atoms in the expanding atmospheres of early-type stars are presented. The influence of these processes on the forbidden-tointercombination line intensity ratio R = f/i for He-like ions (CV, NVI, OVII, etc.) in X-ray spectra is considered. If non-stationarity of the levels is taken into account, the instantaneous value of R m can vary on short time scales (fraction of a second) by nearly three orders of magnitude, compared to the stationary value in an equilibrium plasma. At the same time, the value of this ratio averaged over long time scales (hours and minutes), R a, can vary by 20%, leading to overestimation of the electron number density by up to one to two orders of magnitude.

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Correspondence to V. V. Dushin.

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Original Russian Text © V.V. Dushin, A.F. Kholtygin, 2015, published in Astronomicheskii Zhurnal, 2015, Vol. 92, No. 7, pp. 578–586.

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Dushin, V.V., Kholtygin, A.F. Non-stationary processes in the atmospheres of early-type stars:influence on the forbidden-to-intercombination line intensity ratio. Astron. Rep. 59, 709–716 (2015). https://doi.org/10.1134/S1063772915070033

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  • DOI: https://doi.org/10.1134/S1063772915070033

Keywords

  • Astronomy Report
  • Stationary Plasma
  • Stellar Wind
  • Electron Number Density
  • Stellar Atmosphere