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Measurements of the Singly Ionized Oxygen Auroral Doublet Lines $λλ$7320,7330ÅUsing High Resolution Sky Spectra

Brian D. Sharpee·Tom G. Slanger·David L. Huestis·Philip C. Cosby
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Abstract

The wavelengths of the individual [O II] 2s22p3 2Do(5/2) - 2s22p3 2Po(1/2,3/2) 7320Åand [O II] 2s22p3 2Do(3/2) - 2s22p3 2Po(1/2,3/2) 7330Åauroral doublet component lines have been measured directly in the nightglow for the first time, from high resolution spectra obtained with the HIRES spectrograph on the Keck I telescope at the W.M. Keck Observatory. Specifically, we find 7320Åand 7330Ådoublet splittings of 1.077$\pm$0.003Åand 1.080$\pm$0.003Årespectively, with the former significantly larger than the often quoted and utilized value of 0.8Åfrom Moore (1949, Atomic Energy Levels, Vol 1), and in line with NIST (1.07Å) as well as more recent astrophysical observations of the lines in planetary nebulae including 1.07Åfrom DeRobertis, Osterbrock, & McKee (1985,ApJ,293,459) and 1.09Åfrom Barnett & McKeith (1988,MNRAS,234,241). Our results suggest, however, that adjustments of +0.124Åand +0.131Åshould be made to current NIST wavelengths for the blue and red components of the 7320Ådoublet respectively, while the wavelengths of the 7330Ådoublet components are little changed from current NIST values. The observed intensity ratio of 7320Å/7330Åfrom these measurements agrees with the theoretical value calculated under conditions of thermally populated 2Po levels.

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Brian D. Sharpee, Tom G. Slanger, David L. Huestis, Philip C. Cosby. 2004-01-15. Measurements of the Singly Ionized Oxygen Auroral Doublet Lines $λλ$7320,7330ÅUsing High Resolution Sky Spectra. https://doi.org/10.1086/382869

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