Solar Physics

, Volume 45, Issue 2, pp 301–317 | Cite as

The analysis of XUV emission lines

  • George L. Withbroe
Article

Abstract

A technique for analyzing measurements of XUV spectral line intensities is described. Application of the technique to OSO-4 and OSO-6 spectra indicates that the mean coronal temperature is 2.1 × 106 K in typical active solar regions and that the mean coronal temperature in typical quiet regions ranges from 1.5 × 106 to 2.1 × 106 K. One active region spectrum shows evidence for substantial quantities of coronal material with 2 × 106 < T < 3.5 × 106 K. Measurements from limb spectra show evidence that (1) coronal abundances of N and O are low relative to heavier elements; or (2) that the ionization equilibrium calculations used may contain systematic errors; or (3) that the XUV intensity measurements may be incorrectly calibrated.

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Copyright information

© D. Reidel Publishing Company 1975

Authors and Affiliations

  • George L. Withbroe
    • 1
  1. 1.Center for Astrophysics, Harvard College Observatory and Smithsonian Astrophyslcal ObservatoryCambridgeU.S.A.

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