Hopkins Ultraviolet Telescope determination of the Io torus electron temperature

Abstract

view Abstract Citations (17) References (31) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Hopkins Ultraviolet Telescope Determination of the Io Torus Electron Temperature Hall, D. T. ; Bednar, C. J. ; Durrance, S. T. ; Feldman, P. D. ; McGrath, M. A. ; Moos, H. W. ; Strobel, D. F. Abstract Sulfur ion emissions from the Io plasma torus observed by the Hopkins Ultraviolet Telescope (HUT) in 1990 December have been analyzed to determine the effective temperature of the exciting electrons. Spectra were obtained with a long slit that extended from 3.1 to 8.7 Jupiter radii RJ on both dawn and dusk torus ansae. The average temperature of electrons exciting S(2+) emissions from the dawn ansa is (4800 +/- 2400) K lower than on the dusk ansa, a dawn-dusk asymmetry comparable in both sign and magnitude to that measured by the Voyager Ultraviolet Spectrograph (UVS) experiment. Emissions from S(2+) ions are generated in a source region with electron temperatures in the range 32,000-56,000 K; S(3+) ion emissions are excited by electrons that average 20,000-40,000 K hotter. This distinct difference suggests that the S(3+) emission source region is spatially separate from the S(2+) source region. Estimated relative aperture filling factors suggest that the S(3+) emissions originate from a region more extended out of the centrifugal plane than the S(2+) emissions. Publication: The Astrophysical Journal Pub Date: January 1994 DOI: 10.1086/187159 Bibcode: 1994ApJ...420L..45H Keywords: Electron Energy; Io; Plasma Temperature; Sulfur; Toruses; Ultraviolet Astronomy; Ultraviolet Spectra; Ultraviolet Spectrometers; Ultraviolet Telescopes; Voyager 1 Spacecraft; Voyager 2 Spacecraft; Astronomy; PLANETS AND SATELLITES: INDIVIDUAL IO; PLANETS AND SATELLITES: INDIVIDUAL JUPITER; ULTRAVIOLET: SOLAR SYSTEM full text sources ADS | data products MAST (1)