Upper Limits to Jovian X-Ray Emission from the Uhuru Satellite

Abstract

In the past decade, the study of celestial X-radiation has led to a deeper understanding of physical processes at work both in the Cosmos in general, and in our own solar system in particular. As magnetospheres seem to be universal astrophysical phenomena, it is interesting to search for rather general scaling laws which might govern their large scale energy balance. The study of terrestrial auroral zone X-rays, created by the precipitation of energetic electrons into the upper atmosphere under a wide variety of geomagnetic and solar wind conditions, has given us considerable information about the dynamics of our magnetosphere; in principle, a study of Jovian X-ray emission would do the same for Jupiter. Moreover, if Jovian X-ray activity were detectable at Earth — from satellite or balloon observations, for example — we could acquire a long term picture of the Jovian magnetosphere which might be as revealing as the information gathered by flyby experiments.