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Ultraviolet Emission Line Profiles of Flares and Active Regions

Published online by Cambridge University Press:  14 August 2015

G. E. Brueckner
G. E. Brueckner*
Affiliation:
E. O. Hulburt Center for Space Research, Naval Research Laboratory, Washington, D.C. 20375, U.S.A.

Abstract

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A preliminary description of ultraviolet spectra of active regions and flares, photographed from Skylab by the Naval Research Laboratory's UV Spectrograph is given. The findings can be summarized as follows: (1) Line profiles of medium ionized lines (transition zone lines) show the most pronounced broadenings and shifts in flares and flare like events. (2) Typical full width at half maximum of these lines correspond to Doppler-velocities of 70 km s-1. (3) Shifts of the same magnitude can be observed. (4) Intersystem lines are not broadened nor shifted. (5) Forbidden coronal lines and intersystem lines become enhanced in the flare spectrum at the moment, when the turbulence seen in the allowed transitions, disappears. (6) A very broad line at 1354.2 Å which appears only in flare spectra, seems to be the forbidden transition 3P1 – 3P0 of Fe XXI.

Type
Part 3: Solar Flares
Information
Symposium - International Astronomical Union , Volume 68: Solar X, Gamma, and EUV Radiation , 1975 , pp. 135 - 151
Copyright
Copyright © Reidel 1975 

References

Feldman, U., Doschek, G. A., Cowan, R. D., and Cohen, L.: 1975, Astrophys. J., in press.Google Scholar
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