Skip to Main content Skip to Navigation
Journal articles

Jupiter radio emission induced by Ganymede and consequences for the radio detection of exoplanets

Abstract : By analysing a database of 26 yr of observations of Jupiter with the Nancay Decameter Array, we unambiguously identify the radio emissions caused by the Ganymede-Jupiter interaction. We study the energetics of these emissions via the distributions of their intensities, duration, and power, and compare them to the energetics of the Io-Jupiter radio emissions. This allows us to demonstrate that the average emitted radio power is proportional to the Poynting flux from the rotating Jupiter's magnetosphere intercepted by the obstacle. We then generalize this result to the radio-magnetic scaling law that appears to apply to all plasma interactions between a magnetized flow and an obstacle, magnetized or not. Extrapolating this scaling law to the parameter range corresponding to hot Jupiters, we predict large radio powers emitted by these objects, that should result in detectable radio flux with new-generation radiotelescopes. Comparing the distributions of the durations of Ganymede-Jupiter and Io-Jupiter emission events also suggests that while the latter results from quasi-permanent Alfven wave excitation by Io, the former likely results from sporadic reconnection between magnetic fields Ganymede and Jupiter, controlled by Jupiter's magnetic field geometry and modulated by its rotation.
Document type :
Journal articles
Complete list of metadatas

Cited literature [33 references]  Display  Hide  Download
Contributor : Nathalie Pothier <>
Submitted on : Friday, September 20, 2019 - 2:45:55 PM
Last modification on : Monday, December 14, 2020 - 3:40:34 PM
Long-term archiving on: : Sunday, February 9, 2020 - 3:26:44 AM


Publisher files allowed on an open archive



P. Zarka, M. Marques, C. Louis, V. Ryabov, L. Lamy, et al.. Jupiter radio emission induced by Ganymede and consequences for the radio detection of exoplanets. Astronomy and Astrophysics - A&A, EDP Sciences, 2018, 618, pp.A84. ⟨10.1051/0004-6361/201833586⟩. ⟨insu-02177063⟩



Record views


Files downloads