Jl. Bougeret et al., A SHOCK ASSOCIATED (SA) RADIO EVENT AND RELATED PHENOMENA OBSERVED FROM THE BASE OF THE SOLAR CORONA TO 1 AU, Geophysical research letters, 25(14), 1998, pp. 2513-2516
We present for the first time an almost complete frequency coverage of
a Shock Associated (SA) radio event and related phenomena observed on
May 6, 1996 at 9:27 UT. It is observed from the base of the solar cor
ona up to almost 1 Astronomical Unit (AU) from the Sun by the followin
g radio astronomical instruments: the Ondrejov spectrometer operating
between 4.5 GHz and 1 GHz (radiation produced near the chromosphere);
the Thermopyles Artemis-N spectrograph operating between 600 MHz and 1
10 MHz (distance range about 1.1-1.4 R-. from sun center); the Nancay
Decameter Array operating between 75 and 25 MHz (distance range about
1.4-2 R-.); and the RAD2 and RAD1 radio receivers on the WIND spacecra
ft covering the range from 14 MHz to about 20 kHz (distance range betw
een 3 R-. and about 1 AU). Observations at the Nancay Decameter Array
clearly show that the SA event starts from a coronal type II radio bur
st which traces the progression of a shock wave through the corona abo
ve 1.8 R-.-2 R-. from the sun center. This SA event has no associated
radio emission in the decimetric-metric range, thus there is no eviden
ce for electron injection in the low/middle corona.