THE SOURCE OF JOVIAN AURORAL HISS OBSERVED BY VOYAGER-1

Observations of auroral hiss obtained from the Voyager 1 encounter wit h Jupiter have been reanalyzed. The Jovian auroral hiss was observed n ear the inner boundary of the warm Io torus and has a low-frequency cu toff caused by propagation near the resonance cone. A simple ray traci ng procedure using an offset tilted dipole of the Jovian magnetic fiel d is used to determine possible source locations. The results obtained are consistent with two sources located symmetrically with respect to the centrifugal equator along an L shell (L similar or equal to 5.59) that is coincident with the boundary between the hot and cold regions of the Io tonrs and is located just inward of the ribbon feature obse rved from Earth. The distance of the sources from the centrifugal equa tor is approximately 0.58 +/- 0.01 R(J). Based on the similarity to te rrestrial auroral hiss, the Jovian auroral hiss is believed to be gene rated by beams of low energy (similar to tens to thousands of eV) elec trons. The low-frequency cutoff of the auroral hiss suggests that the electrons are accelerated near the inferred source region, possibly by parallel electric fields similar to those existing in the terrestrial auroral regions. A held-aligned current is inferred to exist at L she lls just inward of the plasma ribbon. A possible mechanism for driving this current is discussed.