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| Titel |
Observational constraint on Jovian active longitude controlling decameter emissions |
| VerfasserIn |
P. H. M. Galopeau, M. Y. Boudjada |
| Konferenz |
EGU General Assembly 2009
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250028615
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| Zusammenfassung |
| The occurrence probability of the Io-controlled Jovian decameter radio emissions depends on
both the central meridian longitude (CML) and the phase of the satellite Io. Recent
investigations by Galopeau et al. (J. Geophys. Res. 112, 2007) have shown that some specific
Jovian ‘active’ longitudes favour the radiation by considering that the emissions are produced
near the local gyrofrequency, along an active magnetic field line carried away by Io along
its revolution around Jupiter, within a hollow cone of constant angle. This model
involves the cyclotron maser instability as the mechanism at the origin of the radio
emission. The observed occurrence probability happens to be larger in some specific
regions of the CML-Io phase diagram, the so-called Io-controlled emissions and
well-known as Io-A, Io-B, Io-C and Io-D ‘sources’. In the present investigation,
we model four boxes representing the typical Io-controlled source regions in this
diagram. We discuss the consequences and the constraints on the location of the
Jovian active longitude at the origin of the Io-controlled radiation simultaneously
for both hemispheres. The first results show that the active longitude model can
only explain part of the emissions coming from restricted zones of the CML-Io
phase diagram. This is particular the case for the emissions of the Io-D source. |
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