Access of solar particles to the interplanetary medium

fl236.pick01
Posted:  18-May-96
Updated: 27-Jan-97
Events specified: See text

M. Pick, D. Maia, P. K. Manoharan, S. Hoang. DASOP, Observatory of Meudon.

Fast electron beams are revealed by the radio emission they produce along their path when they propagate through the corona then in the interplanetary medium (type III emission).

The emission in the corona is produced in decimeter meter range, and in the interplanetary medium typically at kilometer wavelengths. The goals of this proposal are:

1. to understand the coronal origin of the fast electrons which produce the interplanetary type III burst:

• is it a repetitive accelerating site?
• is it a single site or fragmented?

This point will be investigated using positional information obtained with the multifrequency Nancay Radioheliograph.

2. to determine the characteristics of the structures involved and their dynamics:

          
 with the Yohkoh data we can superpose the radio and X
ray     
        images.
          
 the radio experiment aboard the Ulysses spacecraft will     
        provide the interplanetary observations.

We have established a list of about 25 days with interesting events observed jointly by Ulysses and Nancay. To start the study we have selected 5 cases for which we ask for the Yohkoh soft X-ray data:

---

Day Month Year Time interval (UT)

---

 18  February  1993    [ 9:00,12:00]
  4  March     1993    [10:00,15:00]
 19  March     1993    [12:00,15:00]
 26  March     1993    [11:00,16:00]
  5  January   1994    [ 9:00,15:00]

Update 27-Jan-97

Among the five days for which we requested the data, for three of them (march 4 , March 19 and March 26 1993), there were data gaps at the time of the radio events. January 5 1994 is an intersting case. We are presently writing a first report on the results obtained from the comparison between the Nancay radioheliograph and Yohkoh.

For the last day, February 18, 1993, the file was corrupted and we cannot read the data. We are presetly asking again the data for this day. The radio events are intersting and justify a secon request