title: Equatorial X-ray Emissions: Implications for Jupiter's High Exospheric Temperatures
abstract: Observations with the High Resolution Imager on the Rontgensatellit reveal x-ray emissions from Jupiter's equatorial latitudes. The observed emissions probably result from the precipitation of energetic (>300 kiloelectron volts per atomic mass unit) sulfur and oxygen ions out of Jupiter's inner radiation belt. Model calculations of the energy deposition by such heavy ion precipitation and of the resulting atmospheric heating rates indicate that this energy source can contribute to the high exospheric temperatures(>800 kelvin at 0.01 microbar) measured by the Galileo probe's Atmospheric Structure Instrument. Low-latitude energetic particle precipitation must therefore be considered, in addition to other proposed mechanisms such as gravity waves and soft electron precipitation, as an important source of heat for Jupiter's thermosphere.
authors.affiliation: J. H. Waite Jr., G. R. Gladstone, W. S. Lewis, Department of Space Science, Southwest Research Institute, Post Office Box 28510, San Antonio, TX 78228-0510, USA. P. Drossart, DESPA, Observatoire de Paris, F-92195 Meudon Cedex, France. T. E. Cravens and A. N. Maurellis, Department of Physics and Astronomy, University of Kansas, Lawrence, KS 66045-2151, USA. B. H. Mauk, Applied Physics Laboratory, The Johns Hopkins University, Laurel, MD 20723-6099, USA. S. Miller, Department of History, Philosophy, and Communication in Science, University College London, London WC1E 6BT, UK.
authors.initials: JH
authors.lastname: Waite
authors.initials: GR
authors.lastname: Gladstone
authors.initials: WS
authors.lastname: Lewis
authors.initials: P
authors.lastname: Drossart
authors.initials: TE
authors.lastname: Cravens
authors.initials: AN
authors.lastname: Maurellis
authors.initials: BH
authors.lastname: Mauk
authors.initials: S
authors.lastname: Miller