Photospheric abundances of oxygen, neon, and argon derived from the XUV spectrum of an impulsive flare

Journal Article · Thu Nov 01 04:00:00 EST 1990 · Astrophysical Journal; (USA)

DOI:https://doi.org/10.1086/169341· OSTI ID:6316064

Feldman, U; Widing, K G ^[1]

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1. E. O. Hulburt Center for Space Research, Washington, DC (USA)

Relative elemental abundances of O, Ne, Na, Mg, Ar, and Ca are determined from detailed analysis of XUV spectra emitted by an impulsive flare. The electron density measured from three diagnostic line ratios is 2-3 x 10 to the 12th/cu cm. It was found that the relative abundances in the flare are similar to values obtained from or proposed for photospheric material. The ratios of O/Mg, Ne/Mg, and Ar/Mg are about four times higher in the impulsive flare than the values typically observed in the average corona. It is suggested that electric fields above the photosphere may be responsible for the order of magnitude variations between the abundances of the group of elements with high first ionization potentials (FIP) and the group with low FIP. 18 refs.

• OSTI ID: 6316064
• Journal Information: Astrophysical Journal; (USA), Journal Name: Astrophysical Journal; (USA) Vol. 363; ISSN ASJOA; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

640104* -- Astrophysics & Cosmology-- Solar Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ABUNDANCE
ALKALI METALS
ALKALINE EARTH METALS
ARGON
ATMOSPHERES
CALCIUM
CHEMICAL COMPOSITION
ELECTROMAGNETIC RADIATION
ELECTRONS
ELEMENT ABUNDANCE
ELEMENTARY PARTICLES
ELEMENTS
EMISSION SPECTRA
EXTREME ULTRAVIOLET RADIATION
EXTREME ULTRAVIOLET SPECTRA
FERMIONS
FLUIDS
FLUX DENSITY
GASES
IONIZATION
LEPTONS
MAGNESIUM
METALS
NEON
NONMETALS
OXYGEN
PHOTOSPHERE
RADIATIONS
RARE GASES
SODIUM
SOLAR ACTIVITY
SOLAR ATMOSPHERE
SOLAR FLARES
SPECTRA
ULTRAVIOLET RADIATION
ULTRAVIOLET SPECTRA