Identifying the variety of jovian X-ray auroral structures: tying the
morphology of X-ray emissions to associated magnetospheric dynamics
Abstract
We define the spatial clustering of X-rays within Jupiter’s northern
auroral regions by classifying their distributions into ‘X-ray auroral
structures’. Using data from Chandra during Juno’s main mission
observations (24 May 2016 – 8 September 2019), we define five X-ray
structures based on their ionospheric location and calculate the
distribution of auroral photons. The morphology and ionospheric location
of these structures allow us to explore the possibility of numerous
X-ray auroral magnetospheric drivers. We compare these distributions to
Hubble Space Telescope (HST)and Juno (Waves and MAG) data, and a 1D
solar wind propagation model to infer the state of Jupiter’s
magnetosphere. Our results suggest that the five sub-classes of ‘X-ray
structures’ fall under two broad morphologies: fully polar and low
latitude emissions. Visibility modelling of each structure suggests the
non-uniformity of the photon distributions across the Chandra intervals
are likely associated with the switching on/off of magnetospheric
drivers as opposed to geometrical effects. The combination of
ultraviolet (UV) and X-ray morphological structures is a powerful tool
to elucidate the behaviour of both electrons and ions and their link to
solar wind/magnetospheric conditions in the absence of an upstream solar
monitor.