Publication Date:
2019-06-28
Description:
Observations of solar flare spectra over the wavelength range 1.769-1.796 A with the Bent Crystal Spectrometer on the NASA Solar Maximum Mission satellite are presented. The 2P3/2, 2P1/2 and associated satellite transitions of Fe XXVI are identified, their intensities and widths estimated and the results compared with theoretical predictions. For two spectra, which include the isolated n = 2 satellite features, the observations can be reproduced by plasma temperatures of 24,000,000 and 28,400,000 K. Linewidth measurements show evidence for nonthermal velocities of up to 150 km/s. Emission measures derived from the Fe XXVI observations are compared with those from lower temperature Ca XIX and Fe XXV measurements and an emission measure decreasing with temperature is found.
Keywords:
SOLAR PHYSICS
Type:
Royal Astronomical Society; vol. 197
Format:
text
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