HR: 1340h
AN: SH33B-0380    [Abstracts]
TI: Directivity of Solar Type III Radio Bursts Deduced From Ulysses-Wind Simultaneous Observations.
AU: Bonnin, X
EM: xbonnin@noos.fr
AF: LESIA - Observatoire de Paris, LESIA, Observatoire de Paris-Meudon, Place J. Janssen, Meudon, 92195 France
AU: * Maksimovic, M
EM: milan.maksimovic@obspm.fr
AF: LESIA - Observatoire de Paris, LESIA, Observatoire de Paris-Meudon, Place J. Janssen, Meudon, 92195 France
AU: Hoang, S
EM: sang.hoang@obspm.fr
AF: LESIA - Observatoire de Paris, LESIA, Observatoire de Paris-Meudon, Place J. Janssen, Meudon, 92195 France
AB: The solar type III radio bursts are produced by subrelativistic electrons travelling outward along open magnetic field lines to lower densities in the interplanetary medium (IPM). Along their path in the IPM, these electrons trigger intense Langmuir waves which are in part converted into radio emission at the fundamental (F) and/or harmonic (H) of the local plasma frequency. We present observations of these solar type III bursts performed simultaneously by the spacecraft Wind and Ulysses while this latter crossed the ecliptic plane in March 1995. For each of the observed bursts, we localize the radio source in the IPM by : (i) associating the radio source with a solar source active region, (ii) using a simple IPM density model, (ii) making an assumption on the (F/H) radiation mode and (iv) using some direction finding possibilities on the two spacecraft. Once the radio sources are localized in the IPM, we compute, for each of the bursts, the ratios of the fluxes observed by the two spacecraft at serveral frequencies. From a statistical analysis of these ratios, we deduce some geometrical properties of the corresponding radio patterns at several frequencies.
DE: 2114 Energetic particles (7514)
DE: 7534 Radio emissions
SC: SPA-Solar and Heliospheric Physics [SH]
MN: Fall Meeting 2005