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The optical and ultraviolet spectrum of the planetary nebula NGC 2440New measurements of the optical and ultraviolet emission-line intensities of the high-excitation planetary nebula NGC 2440 in the wavelength range 1240-8578 A are analyzed with the aid of photoionization models. The observed O III and N II forbidden-line temperatures (13,800 K and 10,000 K, respectively) differ by more than the models predict. Inclusion of charge-transfer reactions at published rates improves agreement between calculated and observed abundances of many ions, but worsens the agreement for several highly ionized ions. Nitrogen shows a larger overabundance N(N)/N(O) approximately equal to 1.0, whereas ultraviolet lines give a carbon abundance close to the solar value. The refractory elements magnesium, calcium, and iron have similar gas-phase depletions of approximately 1.5 dex. The abundances of oxygen, neon, sodium, sulfur, chlorine, potassium, and argon are rougly solar.
Document ID
19810064637
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Shields, G. A.
(California Univ. Los Angeles, CA, United States)
Aller, L. H.
(California Univ. Los Angeles, CA, United States)
Keyes, C. D.
(California, University Los Angeles, CA, United States)
Czyzak, S. J.
(Ohio State University Columbus, OH, United States)
Date Acquired
August 11, 2013
Publication Date
September 1, 1981
Publication Information
Publication: Astrophysical Journal
Subject Category
Astrophysics
Accession Number
81A49041
Funding Number(s)
CONTRACT_GRANT: NSF AST-77-21022
CONTRACT_GRANT: NSF AST-78-04575
CONTRACT_GRANT: NSF AST-76-15727
CONTRACT_GRANT: NSF AST-78-17836
Distribution Limits
Public
Copyright
Other

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