title: Detection of a deep 3-microm absorption feature in the spectrum of Amalthea (JV).
abstract: Near-infrared spectra of Jupiter's small inner satellites Amalthea and Thebe are similar to those of D-type asteroids in the 0.8- to 2.5-micrometer wavelength range. A deep absorption feature is detected at 3 micrometers in the spectra of the trailing side of Amalthea, which is similar to that of the non-ice components of Callisto and can be attributed to hydrous minerals. These surface materials cannot be explained if the satellite formed at its present orbit by accreting from a circumjovian nebula. Amalthea and Thebe may be the remnants of Jupiter's inflowing building blocks that formed in the outer part or outside of the circumjovian nebula.
authors.affiliation: Subaru Telescope, National Astronomical Observatory of Japan, 650 North Aohoku Place, Hilo, Hawaii 96720, USA. takato@naoj.org
authors.forename: Naruhisa
authors.initials: N
authors.lastname: Takato
authors.forename: Schelte J
authors.initials: SJ
authors.lastname: Bus
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Terada
authors.forename: Tae-Soo
authors.initials: TS
authors.lastname: Pyo
authors.forename: Naoto
authors.initials: N
authors.lastname: Kobayashi
mesh_terms: D007053:Ice; D018538:Jupiter; D008903:Minerals; D019265:Spectroscopy, Near-Infrared; D013696:Temperature; D014867:Water
chemical_list: D007053:Ice; D008903:Minerals; D014867:Water