Position and Polarization of Solar Drift Pair Bursts

Extract

Reverse drift pairs were first described by Roberts (1958) and later by Ellis (1969) and de la Nòe and Moller-Pedersen (1971). Figure 1 shows a 10-min section of the spectrograph record and the corresponding section of the polarimeter record. The figure contains several reverse drift pairs and illustrates the main features of RDPs, namely: (1) frequency drift rate of about 4 MHz s^-1 (i.e. a factor of ~50 faster than Type lis and a factor of ~2 slower than type Ills); (2) drift to higher frequencies (i.e. opposite to that of Type II and III bursts, hence the name ‘reverse’); and (3) an apparent ‘echo’ of the burst some 1 to 2 s later to form a pair. On 1979 February 17/18 a noise storm consisting of Type 1 bursts, Type III bursts and an underlying continuum was observed with the Culgoora spectropolarimeter, spectrograph, and radioheliograph. During this noise storm, the spectrograph record showed several hundred RDP bursts, and about fifty FDPs. Here we report new results on the polarization-of drift pair bursts, present further data on RDP positional and frequency characteristics, and then comment on existing theories concerning RDPs.