Localization of Io and non-Io sources of Jovian decameter emission

Abstract

The observation of interplanetary scintillations (IPS) of the decameter radio emission from Jupiter provides information about the structure and position of the sources of emission. The paper presents the analysis of all the observations made at Nançay during the years 1978 and 1979. The authors confirm the preliminary results of Genova and Boischot (1981) on the frequency drift on the IPS patterns indicating that the emission is spatially distributed along field lines, and the localization of Io-controlled A and B sources on opposite sides of Jupiter. It is furthermore shown that the non-Io sources A and B behave exactly like the Io-sources. It is concluded that the non-Io emissions come from sources along magnetic field lines seen at large distance from the central meridian, on the East for the non-Io-B source and on the West for the non-Io-A. The emission mechanism is thus to be the same for Io-controlled and Io-independent sources.