Wednesday

X-ray emissions from Jupiter’s poles were first witnessed by the Einstein Observatory and subsequently by ROSAT. The launches of Chandra and XMM-Newton twenty years ago have helped to greatly improve our understanding of Jupiter’s X-ray aurorae. Unlike at the Earth, Jupiter’s north and south aurorae behave independently and may hint that the polar regions are at times driven by highly energetic, non-conjugate magnetospheric processes. Juno’s arrival at Jupiter in 2016 has meant that in situ data can be used to complement the data obtained by Chandra and XMM-Newton. Furthermore, the polar orbit of Juno has given us views of Jupiter’s aurorae that remote sensing telescopes never could.

XMM-Newton carries three large collecting area X-ray telescopes equipped with CCD cameras collectively known as the EPIC instrument. The pn camera collects the full beam focussed by the first telescope, while the two MOS cameras receive only half of the photons entering the second and third telescopes. The rest of the photons are directed to the secondary RGS foci.

Our observation campaign with XMM-Newton occurred over 26 hours between 16th and 17th July 2017 and coincided with Juno being in Jupiter’s plasma sheet. Spectra of the northern and southern X-ray aurorae were extracted for the three EPIC cameras, combined and spectral fitting was carried out using an ion charge exchange model. We present novel results of the composition and abundances of the ions responsible for producing the X-ray aurorae which appear to support in situ measurements by Juno.