10:00 AM - 10:15 AM
[PPS01-05] Auroral Electron Energy Estimation Using H/H2 Brightness Ratio Applied to Jupiter
Keywords:Jupiter, aurora, ultraviolet emission
We use HST/STIS long-slit spectra taken on the first half of January 2014 (ID: GO13035). Since HST observes Jupiter from the orbit around the Earth, it contains Lyman-α emissions from geo-coronal hydrogen atoms, in addition to Jupiter's coronal emission. We remove these contaminations by subtracting the emission at the disc. The H/H2 brightness ratio is then evaluated by spectral fitting following the previous auroral analysis for Saturn.
As a result, we show that the H/H2 brightness ratio decreases with increasing H2 brightness, which is qualitatively similar to the Saturn's case, but with different quantitative values. The H/H2 brightness ratio, i.e., low energy electron precipitation, does not show clear relationship with the FUV CR, i.e., higher energy electron precipitation. Comparing to the same analysis applied to Saturn aurora, the relation at Jupiter shows decreasing flux with increasing energy without acceleration feature for the low energy range.