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Measurements of [C I] 9850 A Emission from Comet Hale-BoppWe present quantitative measurements of cometary [C I] 9850 A, emission obtained during observations of comet Hale-Bopp (C/1995 O1) in 1997 March and April. The observations were carried out using a high-resolution (lambda/Delta lambda approx. 40,000) Fabry-Perot/CCD spectrometer at the McMath-Pierce solar telescope on Kitt Peak. This forbidden line, the carbon analog of [O I] 6300 A, is emitted in the radiative decay of C(1D) atoms. In the absence of other sources and sinks, [C I] 9850 A emission may be used as a direct tracer of CO photodissociation in comets. However, in Hale-Bopp's large, dense coma, other processes, such as collisional excitation of ground-state C(3P), dissociative recombination of CO+, and collisional dissociation of CO and CO2 may produce significant amounts of C(1D). The long C(1D) radiative lifetime (approx. 4000 s) makes collisional de-excitation (quenching) the primary loss mechanism in the inner coma. Thus, a detailed, self-consistent global model of collisional and photochemical interactions is necessary to fully account for [C I] 9850 A emission in comet Hale-Bopp.
Document ID
20030032989
Acquisition Source
Goddard Space Flight Center
Document Type
Preprint (Draft being sent to journal)
Authors
Oliversen, R. J.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Doane, N.
(National Solar Observatory United States)
Scherb, F.
(National Solar Observatory United States)
Harris, W. M.
(Wisconsin Univ. Madison, WI, United States)
Morgenthaler, J. P.
(Wisconsin Univ. Madison, WI, United States)
Date Acquired
September 8, 2013
Publication Date
January 1, 2002
Subject Category
Lunar And Planetary Science And Exploration
Distribution Limits
Public
Copyright
Other

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