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Titel |
The far-ultraviolet main auroral emission at Jupiter – Part 2: Vertical emission profile |
VerfasserIn |
B. Bonfond, J. Gustin, J.-C. Gérard, D. Grodent, A. Radioti, B. Palmaerts, S. V. Badman, K. K. Khurana, C. Tao |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
0992-7689
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Digitales Dokument |
URL |
Erschienen |
In: Annales Geophysicae ; 33, no. 10 ; Nr. 33, no. 10 (2015-10-01), S.1211-1219 |
Datensatznummer |
250121253
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Publikation (Nr.) |
copernicus.org/angeo-33-1211-2015.pdf |
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Zusammenfassung |
The aurorae at Jupiter are made up of many different features associated with
a variety of generation mechanisms. The main auroral emission, also known as
the main oval, is the most prominent of them as it accounts for approximately
half of the total power emitted by the aurorae in the ultraviolet range. The
energy of the precipitating electrons is a crucial parameter to characterize
the processes at play which give rise to these auroral emissions, and the
altitude of the emissions directly depends on this energy. Here we make use
of far-UV (FUV) images acquired with the Advanced Camera for Surveys on board
the Hubble Space Telescope and spectra acquired with the Space Telescope
Imaging Spectrograph to measure the vertical profile of the main emissions.
The altitude of the brightness peak as seen above the limb is ~ 400 km,
which is significantly higher than the 250 km measured in the post-dusk
sector by Galileo in the visible domain. However, a detailed analysis of the
effect of hydrocarbon absorption, including both simulations and FUV spectral
observations, indicates that FUV apparent vertical profiles should be
considered with caution, as these observations are not incompatible with an
emission peak located at 250 km. The analysis also calls for spectral
observations to be carried out with an optimized geometry in order to remove
observational ambiguities. |
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