Skylab observations of the Al I autoionization lines lambda1932 and lambda1936 during a solar flare

Journal Article · Thu Nov 15 04:00:00 EST 1979 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/157505· OSTI ID:5636967

Cook, J W

Observations are presented of the Al I autoionization lines lambda1932 and lambda1936 during the H..cap alpha.. class SN subflare of 1973 August 9, obtained from the NRL slit spectrograph aboard Skylab. These profiles are compared with observations from an active-region plage and with the quiet-Sun observations of McAllister. Line profiles through model flare and quiet-Sun atmospheres are computed assuming local thermodynamic equilibrium. The Al I autoionization lines are found to be sensitive to the condition just below the temperature-minimum region of the model atmosphere, and the observations support earlier evidence that increased heating of this region occurs during flares. We show, using observions from three additional flares, that excess flare heating down to the T/sub min/ region probably occurs only near loop footpoints. We also comment on the behavior of Fe I and Fe II in the 1920--1950 A range.

• Research Organization: E. O. Hulburt Center for Space Research, Naval Research Laboratory, Washington
• OSTI ID: 5636967
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 233:4; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640104* -- Astrophysics & Cosmology-- Solar Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ALUMINIUM
ATMOSPHERES
AUTOIONIZATION
ELEMENTS
EQUILIBRIUM
IONIZATION
LTE
METALS
PLAGES
SOLAR ACTIVITY
SOLAR FLARES
SPECTRA
STELLAR ATMOSPHERES
ULTRAVIOLET SPECTRA