Comparing Jupiter's Equatorial X-Ray Emissions With Solar X-Ray Flux Over 19Years of the Chandra Mission.

Abstract

We present a statistical study of Jupiter's disk X-ray emissions using 19years of Chandra X-Ray Observatory (CXO) observations. Previous work has suggested that these emissions are consistent with solar X-rays elastically scattered from Jupiter's upper atmosphere. We showcase a new pulse invariant (PI) filtering method that minimizes instrumental effects which may produce unphysical trends in photon counts across the nearly two-decade span of the observations. We compare the CXO results with solar X-ray flux data from the Geostationary Operational Environmental Satellites X-ray Sensor for the wavelength band 1-8Å (long channel), to quantify the correlation between solar activity and Jovian disk counts. We find a statistically significant Pearson's Correlation Coefficient of 0.9, which confirms that emitted Jovian disk X-rays are predominantly governed by solar activity. We also utilize the high spatial resolution of the High Resolution Camera Instrument on-board the CXO to map the disk photons to their positions on Jupiter's surface. Voronoi tessellation diagrams were constructed with the Juno Reference Model through Perijove 9 internal field model overlaid to identify any spatial preference of equatorial photons. After accounting for area and scattering across the curved surface of the planet, we find a preference of Jovian disk emission at 2-3.5 Gauss surface magnetic field strength. This suggests that a portion of the disk X-rays may be linked to processes other than solar scattering: the spatial preference associated with magnetic field strength may imply increased precipitation from the radiation belts, as previously postulated.