Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1769097 | Advances in Space Research | 2006 | 6 Pages |
Abstract
We derive the speed along the interplanetary field of the leading edge and peak flux density from dynamic WIND/WAVES spectrograms of interplanetary type-III fast-drift radio bursts associated with 52 beam-like near-relativistic electron events observed at 1Â AU from 1997 to 2000. The speeds of the leading edge and peak are established by a best fit to time-frequency points obtained from different frequency cuts of the WAVES spectrograms. These are the points when the flux density first rises above the pre-event level or reaches the peak flux density, respectively. The peak flux speeds are usually <0.1c with a median of 0.065c. While the speeds assigned to the leading edge can sometimes exceed 0.3c, their median speed is 0.15c (electron excitation energy of 6Â keV). We examine the speeds of the leading edge of the type-III bursts with respect to the delayed injection of the near-relativistic electrons measured at ACE to determine whether the speeds are correlated with the observed delays. We find a poor correlation and interpret this as no significant association between the low-energy electrons in the type-III leading edge and the population of near-relativistic electrons.
Keywords
Related Topics
Physical Sciences and Engineering
Earth and Planetary Sciences
Space and Planetary Science
Authors
Dennis K. Haggerty, Edmond C. Roelof,