Jupiter’s X-ray Aurora Spectra 2016-2017

Poleward of Jupiter’s main auroral emission, there are diverse dynamic multi-waveband aurorae. The most energetic photons observed from this region are X-rays. Most of these X-rays are produced when high-energy (~10s MeV) ions collide with Jupiter’s atmosphere [Gladstone et al. 2002; Elsner et al. 2005; Branduardi-Raymont et al. 2007; 2008]. These X-ray emissions typically pulse and change morphology, intensity and precipitating particle populations from observation to observation and pole to pole [Kimura et al. 2016; Dunn et al. 2016; 2017; Jackman et al., in review]. The acceleration process/es that allow Jupiter to produce X-rays remain to be confirmed, but probably involve a combination of outer magnetosphere processes and local acceleration at the pole [Cravens et al. 2003; Bunce et al. 2004; Clark et al. 2017; Paranicas et al. 2018]. We present an overview of ~100 hours of XMM-Newton observations of Jupiter from 2016-17 and focus on a 40-hour continuous observation from July 10-12th 2017, during Juno PJ 7. At this time, we observe significant changes in the X-ray aurora from Jupiter rotation to rotation. Amongst these changes, we observe time-varying auroral pulsation rates , which change from a non-regular interval to regular 10-13-min (40-45-min) Northern (Southern) auroral pulses. We also observe time-varying accelerations, with a transient possible sulphur XV line suggesting that the ions may sometimes precipitate with energies in excess of 64 MeV [Kharchenko et al. 2008]. Alongside a range of auroral sulphur and oxygen lines that have previously been observed [Elsner et al. 2005; Branduardi-Raymont et al. 2007; Dunn et al. 2016], we also find spectral lines that are not catalogued as oxygen or sulphur lines, but are at known wavelengths for carbon and/or nitrogen and magnesium, suggesting that the species and abundances of the precipitating ion populations may change with time and/or space. We finish by trying to place these results in the context of other wavebands and their possible physical drivers.