Far-UV emissions from the SL9 impacts with Jupiter
Talavera, A.; Feldman, P. D.; Strobel, D. F.; Liu, X.; Combi, M. R.; Clarke, J. T.; Gladstone, G. R.; Ballester, G. E.; Harris, W. M.; McGrath, M. A.; Ajello, J. M.; Livengood, T. A.; Budzien, S. A.; Emerich, C.; Miller, S.; Jessup, K. L.; Prangé, R.; Rego, D.; Hall, D. T.; Vincent, M. B.; ben Jaffel, L.; Fireman, G.; Woodney, L.
United States, France, Spain, United Kingdom
Abstract
Observations with the International Ultraviolet Explorer (IUE) during the impacts of the fragments of comet D/Shoemaker-Levy 9 with Jupiter show far-UV emissions from the impact sites within a ∼10 min time scale. Positive detections of H2 Lyman and Werner band (1230-1620 Å) and H-Lyα emissions are made for impacts K and S, and marginally for P2. No thermal continuum is observed. The radiated far-UV output was >1021 ergs. The H2 spectrum is consistent with electron collisional excitation if significant CH4 absorption is included. Such emissions could result from plasma processes generated by the impacts. Non-thermal excitation by the high altitude entry and explosion shocks may also be relevant. Emissions by Al+ (1671 Å) and C (1657 Å) of cometary origin are tentatively identified.