A Highly Circularly Polarized Solar Radio Emission Component Observed at Hectometric Wavelengths |
| |
Authors: | M J Reiner M L Kaiser J Fainberg J -L Bougeret |
| |
Institution: | (1) The Catholic University of America and NASA/Goddard Space Flight Center, Greenbelt, Maryland, U.S.A.;(2) NASA/Goddard Space Flight Center, Greenbelt, Maryland, U.S.A.;(3) Observatoire de Paris, Meudon, France |
| |
Abstract: | We report here the observation of a rare solar radio event at hectometric wavelengths that was characterized by essentially
100% circularly polarized radiation and that was observed continuously for about six days, from May 17 to 23, 2002. This was
the first time that a solar source with significantly polarized radiation was detected by the WAVES experiment on the
Wind spacecraft. From May 19 to 22, the intense polarized radio emissions were characterized by quasi-periodic intensity variations
with periods from one to two hours and with superposed drifting, narrowband, fine structures. The bandwidth of this radiation
extended from about 400 kHz to 7 MHz, and the peak frequency of the frequency spectrum slowly decreased from 2 MHz to about
0.8 MHz over the course of four days. The radio source, at each frequency, was observed to slowly drift from east to west
about the Sun, as viewed from the Earth and was estimated to lie between 26 and 82R⊙ (R⊙ = 696 000 km). We speculate that this unusual event may represent an interplanetary manifestation of a moving type IV burst
and discuss possible radio emission mechanisms. The ISEE-3 spacecraft may possibly have detected a similar event some 26 years
ago. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|