Journal article
Radio emissions observed by Galileo near Io
Geophysical research letters, Vol.25(1), pp.25-28
1998
DOI: 10.1029/97GL03442
Abstract
The Galileo spacecraft observed spin modulation of radio wave emissions near Io in the frequency range from about 600 kHz to about 1.2 MHz. Assuming transverse EM radiation, we have used the modulation of the high-frequency sweep-frequency receiver signals of the electric dipole antenna over many spins to estimate the plane through the source. The emission has a range of frequencies close to the local upper hybrid frequency of the plasma near Io. We conclude that the emission may be associated with either the plasma torus or magnetic flux tubes in the wake of Io (the Alfvén current system). We postulate this emission may be associated with a free-energy source such as density gradients, energetic plasma beams and/or an electron distribution with a temperature anisotropy. All of these free-energy sources are observed or expected in the torus near Io. The observations are the first in the hectometric frequency range that have a source associated with Io or in the Io torus.
Details
- Title: Subtitle
- Radio emissions observed by Galileo near Io
- Creators
- J. D Menietti - University of IowaD. A Gurnett - University of IowaW. S Kurth - University of IowaJ. B Groene - University of IowaL. J Granroth - University of Iowa
- Resource Type
- Journal article
- Publication Details
- Geophysical research letters, Vol.25(1), pp.25-28
- Publisher
- American Geophysical Union
- DOI
- 10.1029/97GL03442
- ISSN
- 0094-8276
- eISSN
- 1944-8007
- Language
- English
- Date published
- 1998
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984455553902771
Metrics
1 Record Views