Correlations Between Jupiter's X-ray Aurora and the Outer Magnetosphere Plasma Sheet

Jupiter produces dynamic X-ray auroral emissions at both of its poles [e.g Gladstone et al. 2002; Cravens et al. 2003; Elsner et al. 2005; Branduardi-Raymont et al. 2004; 2007; Dunn et al. 2017]. These consist of two main components: 1. a lower latitude bremsstrahlung emission from precipitating electrons along the UV main emission [Branduardi-Raymont et al. 2004; 2008] and 2. a more dominant poleward emission from the precipitation of highly energetic ions [e.g. Elsner et al. 2005; Branduardi-Raymont et al. 2007]. These emissions are often observed to pulse, sometimes erratically and sometimes with a regular beat (e.g. Jackman et al. 2018). For much of the last two decades, these remote signatures of energetic ion precipitations have been interpreted as indicators of the processes at Jupiter's cusp and/or Jupiter's return current system [e.g. Bunce et al. 2004; Cravens et al. 2003]. Here, we report on an extensive campaign totalling hundreds of hours of Jupiter observations by XMM-Newton that were conducted coincident with in-situ measurements of Jupiter by NASAs Juno mission. By comparing data from XMM-Newton and Junos JEDI, WAVES and MAG instruments, we identify strong correlations between events at 50- 70 Jupiter radii in the outer magnetosphere and Jupiter's X-ray auroral emissions. Strangely, these correlations connect the dawn and night-side magnetosphere with the aurora and not the expected noon magnetosphere [Dunn et al. 2016; Kimura et al. 2016]. We finish by leveraging our understanding of the UV emissions to interpret the triggers of these processes.