Heavy Ion Charge States in Jupiter's Polar Magnetosphere Inferred From Auroral Megavolt Electric Potentials

In this paper, we exploit the charge‐dependent nature of auroral phenomena in Jupiter's polar cap region to infer the charge states of energetic oxygen and sulfur. To date, there are very limited and sparse measurements of the >50 keV oxygen and sulfur charge states, yet many studies have demonstrated their importance in understanding the details of various physical processes, such as X‐ray aurora, ion‐neutral interactions in Jupiter's neutral cloud, and particle acceleration theories. In this contribution, we develop a technique to determine the most abundant charge states associated with heavy ions in Jupiter's polar magnetosphere. We find that O+ and S++ are the most abundant and therefore iogenic in origin. The results are important because they provide (1) strong evidence that soft X‐ray sources are likely due to charge stripping of magnetospheric ions and (2) a more complete spatial map of the oxygen and sulfur charge states, which is important for understanding how the charge‐ and mass‐dependent physical processes sculpt the energetic particles throughout the Jovian magnetosphere. Key Points Quasi‐static electric potentials in Jupiter's polar cap region are used to determine the energetic (>hundreds of keV) ion charge states The most abundant charge states associated with these precipitating ions are O+ and S++ and therefore iogenic in origin These observations are important for X‐ray auroral and ion‐neutral interaction physics