TY - JOUR

T1 - ИОНИЗАЦИЯ И ОХЛАЖДЕНИЕ ГОРЯЧЕЙ ПЛАЗМЫ С ФЛУКТУАЦИЯМИ ТЕМПЕРАТУРЫ

AU - Kholtygin, AF

AU - Bratsev, VF

AU - Ochkur, V.I.

PY - 2002

Y1 - 2002

N2 - Cooling functions for a stationary plasma are calculated in a wide temperature range from 5.10(3) K to 10(8) K, both for a plasma with the solar abundances of elements and for a plasma with an anomalous chemical composition typical of Wolf-Rayet stars. The HILYS project is described, with the aim of calculating cross sections and rates of excitation by electron collision of atoms and ions with a charge Z less than or equal to 26 and principal electron quantum numbers n less than or equal to 10, needed to calculate the ionization and thermal states of a plasma and the development of methods of calculating the plasma's spectrum in the visible, UV, and x-ray ranges. The results of a calculation of cross sections and effective collision strengths obtained within the framework of the project are given. The influence of temperature fluctuations (deltaT/T less than or equal to 0.16) on the relative, ion abundances and the total cooling function is studied. It is shown that the presence of such fluctuations considerably increases the temperature range in which the abundances of ions of a given degree of ionization are not negligible, while the cooling function can differ considerably from that calculated for a one-temperature plasma: The contribution of dielectronic recombination to the total cooling function is investigated, and it proves to be significant only for a plasma with high abundances of heavy elements. The x ray spectrum of the bright supergiant zeta Pup is analyzed.

AB - Cooling functions for a stationary plasma are calculated in a wide temperature range from 5.10(3) K to 10(8) K, both for a plasma with the solar abundances of elements and for a plasma with an anomalous chemical composition typical of Wolf-Rayet stars. The HILYS project is described, with the aim of calculating cross sections and rates of excitation by electron collision of atoms and ions with a charge Z less than or equal to 26 and principal electron quantum numbers n less than or equal to 10, needed to calculate the ionization and thermal states of a plasma and the development of methods of calculating the plasma's spectrum in the visible, UV, and x-ray ranges. The results of a calculation of cross sections and effective collision strengths obtained within the framework of the project are given. The influence of temperature fluctuations (deltaT/T less than or equal to 0.16) on the relative, ion abundances and the total cooling function is studied. It is shown that the presence of such fluctuations considerably increases the temperature range in which the abundances of ions of a given degree of ionization are not negligible, while the cooling function can differ considerably from that calculated for a one-temperature plasma: The contribution of dielectronic recombination to the total cooling function is investigated, and it proves to be significant only for a plasma with high abundances of heavy elements. The x ray spectrum of the bright supergiant zeta Pup is analyzed.

KW - X-RAY-EMISSION

KW - PLANETARY-NEBULAE

KW - ABUNDANCES

KW - SPECTRUM

KW - CARBON

KW - STARS

M3 - статья

VL - 45

SP - 32

EP - 45

JO - Astrophysics

JF - Astrophysics

SN - 0571-7256

IS - 1

ER -