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EUV Emission Sources in Gas-Dynamic Models of Stellar Flares

Published online by Cambridge University Press:  12 April 2016

M.A. Livshits
Affiliation:
Institute of Terrestrial Magnetism, Ionosphere, and Radio Wave Propagation, Russian Academy of Sciences, 142092 Troitsk, Moscow Region, Russia
M.M. Katsova
Affiliation:
Sternberg State Astronomical Institute, Moscow State University, 119899 Moscow, Russia

Abstract

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A stellar flare model in which the main energy release is located above the chromosphere based on a set of elementary acts of the electron acceleration or impulsive heating of plasma is discussed. The response of the chromosphere to impulsive heating for both a single burst and the simultaneous effect of a set of the bursts is considered.

The results of numerical modeling of the process of explosive evaporation of the stellar chromosphere allow us to select 3 classes of EUV emission source: (1) the bursts of the EUV emission in the temperature range of 3 · 104 – 3 · 105 K at the beginning of each of elementary act of the energy release; (2) the bursts of the EUV emission at temperatures T ≈ 106 K, accompanied by outflow of heated plasma; (3) the EUV emission, caused by new features of the process, namely, when the maxima of the distribution of the pressure are forming in the region of the downward-moving thermal front.

The properties of the EUV sources, velocities of the plasma motions therein, and possible behaviour of the light curve for an elementary burst are discussed.

Type
III. Coronae of Cool Stars
Copyright
Copyright © Kluwer 1996

References

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