THE ION-INDUCED CHARGE-EXCHANGE X-RAY EMISSION OF THE JOVIAN AURORAS: MAGNETOSPHERIC OR SOLAR WIND ORIGIN?

A new and more comprehensive model of charge-exchange induced X-ray emission, due to ions precipitating into the Jovian atmosphere near the poles, has been used to analyze spectral observations made by the Chandra X-ray Observatory. The model includes for the first time carbon ions, in addition to the oxygen and sulfur ions previously considered, in order to account for possible ion origins from both the solar wind and the Jovian magnetosphere. By comparing the model spectra with newly reprocessed Chandra observations, we conclude that carbon ion emission provides a negligible contribution, suggesting that solar wind ions are not responsible for the observed polar X-rays. In addition, results of the model fits to observations support the previously estimated seeding kinetic energies of the precipitating ions (∼0.7-2 MeV u-1), but infer a different relative sulfur-to-oxygen abundance ratio for these Chandra observations.