Effelsberg observations of the evolution of Jupiterʹs radio brightness during and after the impacts of comet Shoemaker-Levy 9

The Effelsberg 100 m Radio Telescope monitored Jupiterʹs radio brightness before, during and after the impacts of comet Shoemaker-Levy 9. Significant increases in the nonthermal flux density were detected during the week of impacts. The brightness level did not rise uniformly during the impact week. The net increase in flux density at the end of the impact week was very nearly constant for all System III longitudes. The timescale of the subsequent exponential decay was τ ⋍ 100 days (e-folding time) immediately following the impacts, but increased as the relaxation continued. The relaxation process back to preimpact emission levels was quicker at the longer wavelengths.