title: Evidence for global electron transportation into the jovian inner magnetosphere.
abstract: Jupiter's magnetosphere is a strong particle accelerator that contains ultrarelativistic electrons in its inner part. They are thought to be accelerated by whistler-mode waves excited by anisotropic hot electrons (>10 kiloelectron volts) injected from the outer magnetosphere. However, electron transportation in the inner magnetosphere is not well understood. By analyzing the extreme ultraviolet line emission from the inner magnetosphere, we show evidence for global inward transport of flux tubes containing hot plasma. High-spectral-resolution scanning observations of the Io plasma torus in the inner magnetosphere enable us to generate radial profiles of the hot electron fraction. It gradually decreases with decreasing radial distance, despite the short collisional time scale that should thermalize them rapidly. This indicates a fast and continuous resupply of hot electrons responsible for exciting the whistler-mode waves.
authors.affiliation: Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA), Sagamihara, Japan. kazuo@stp.isas.jaxa.jp.
authors.forename: K
authors.initials: K
authors.lastname: Yoshioka
authors.affiliation: Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA), Sagamihara, Japan.
authors.forename: G
authors.initials: G
authors.lastname: Murakami
authors.affiliation: Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA), Sagamihara, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Yamazaki
authors.affiliation: Planetary Plasma and Atmospheric Research Center, Tohoku University, Sendai, Japan.
authors.forename: F
authors.initials: F
authors.lastname: Tsuchiya
authors.affiliation: Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA), Sagamihara, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Kimura
authors.affiliation: Planetary Plasma and Atmospheric Research Center, Tohoku University, Sendai, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Kagitani
authors.affiliation: Planetary Plasma and Atmospheric Research Center, Tohoku University, Sendai, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Sakanoi
authors.affiliation: Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA), Sagamihara, Japan. National Astronomical Observatory of Japan, Mitaka, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Uemizu
authors.affiliation: Department of Geophysics, Tohoku University, Sendai, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Kasaba
authors.affiliation: Department of Earth and Planetary Science, University of Tokyo, Tokyo, Japan.
authors.forename: I
authors.initials: I
authors.lastname: Yoshikawa
authors.affiliation: Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA), Sagamihara, Japan. Earth-Life Science Institute, Tokyo Institute of Technology, Tokyo, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Fujimoto