High-resolution spectroscopy of the C2 Swan 0-0 band from Comet P/Halley
- Texas Univ., Austin (USA) Applied Research Corp., Landover, MD (USA) Liege Univ. de l'Etat (Belgium) European Southern Observatory, La Silla (Chile)
High-resolution spectra of the C2 Swan system's 0-0 band from Comet P/Halley in March 1986 show that the populations of the upper state's rotational levels may be described by two rotational temperatures. The low rotational levels provide a low temperature, Trot = about 600 - 700 K. The higher levels correspond to about 3200 K. If a contribution from the 3200-K molecules is subtracted from the populations of the low-J-prime levels, the latter are characterized by Trot = about 190 K. A comparison with recent predictions for C2 molecules fluorescing in sunlight shows that the observed and predicted level populations are in good agreement for J-prime greater than about 15, but there is a sharp disagreement for the low rotational levels. 26 refs.
- OSTI ID:
- 7040595
- Journal Information:
- Astrophysical Journal; (USA), Vol. 353; ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
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