view Abstract Citations (48) References (23) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Rocket Observation of Ar XII-XVI Ca XIV-XVIII and Fe XIV, XV, XXIV in the Extreme-Ultraviolet Spectrum of a Solar Flare Purcell, J. D. ; Widing, K. G. Abstract The lithiumlike doublets of S xiv, Ar XVI, and Ca xviii are identified in the 300-450 A region by extrapolation of solar wavelengths and term intervals in the isoelectronic sequence. A possible observation of Fe xxiv in the flare is discussed. The solar blend at 417 A involving S xiv and the Fe xv inter- system line is resolved. The singlet resonance lines of S xiii, Ar xv, and Ca xvii are also found in the flare spectrum by isoelectronic extrapolation. Ca xiv and Ca xv are identified on the basis of laboratory wavelengths. The problem of the identification of boron-like Ar xiv and Ca xvi is discussed. The weakness of argon lines relative to calcium lines in the flare is consistent with a solar abundance of argon less than calcium. An electron density of 3 >( 1010 in the flare core is estimated from the intensity ratio of the Fe xiv lines at 211 and 219 A. Publication: The Astrophysical Journal Pub Date: August 1972 DOI: 10.1086/151626 Bibcode: 1972ApJ...176..239P full text sources ADS |