Anomalous molecular abundances and the depletion of NH sub 2 in Comet P/Giacobini-Zinner
Observations of the CN, C2, C3, and NH2 molecules in spectra of the Comet P/Giacobini-Zinner (P/G-Z) obtained during the 1985 apparition are presented. Haser-model production rates are derived, and it is found that Q(C2)/Q(CN) and Q(C3)/Q(CN) are low compared to those in normal comets. This indicate...
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Published in | The Astrophysical journal Vol. 360 |
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Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
United States
01.09.1990
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Subjects | |
Online Access | Get full text |
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Summary: | Observations of the CN, C2, C3, and NH2 molecules in spectra of the Comet P/Giacobini-Zinner (P/G-Z) obtained during the 1985 apparition are presented. Haser-model production rates are derived, and it is found that Q(C2)/Q(CN) and Q(C3)/Q(CN) are low compared to those in normal comets. This indicates that C2 and C3 were underabundance in P/G-Z, in agreement with previous results. Q(NH2)/Q(CN) is determined for five comets for the first time to determine a normal value for this ratio. The ratio for P/G-Z is low compared to the value for the ensemble, suggesting that NH2 was underabundant. For the five-comet sample, Q(C3)/Q(CN) exhibits a strong dependence with heliocentric distance, in contrast to Q(C2)/Q(CN) and Q(C3)/Q(CN). The dust-to-gas ratio is characterized by calculating the product of the dust-grain albedo, the filling factor, and the projected radius of the aperture and by computing the dust-to-gas mass ratio. 15 refs. |
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ISSN: | 0004-637X 1538-4357 |
DOI: | 10.1086/169155 |