Detection and Diagnostics of a Coronal Shock Wave Driven by a Partial-Halo Coronal Mass Ejection on 2000 June 28
AIR FORCE RESEARCH LAB HANSCOM AFB MA SPACE VEHICLES DIRECTORATE
Pagination or Media Count:
A fast partial-halo coronal mass ejection CME was observed on 2000 June 28 by instruments on the SOHO spacecraft. The CME leading edge and filamentary cold core were detected over the northwest limb at 2.32 Rcircle dot solar by the SOHO UV Coronagraph Spectrometer UVCS. The broad profile of the O VI lambda-1032 line gives evidence of a shock front at the leading edge, supporting the identification of white-light CME sharp leading edges as fast-mode shocks. Line-of-sight speeds are as high as 1500 km s-1, comparable to the projected speed obtained from LASCO. Pumping of the O VI lambda-1032 by Ly-beta upsilon1810 km s-1 and of O VI lambda-1037 by O VI lambda-1032 upsilon1648 km s-1 were detected, which provide diagnostics of outflow speed and density. The angle of the ejecta with the plane of the sky is obtained, combining the projected speed from LASCO with the line-of-sight speed, and varies between 7 degrees and 46 degrees. In the latter case the projected height of 2.32 Rcircle dot solar was at an actual heliocentric distance of 3.6 Rcircle dot solar. An associated solar energetic particle SEP event was observed at the L1 point following this CME. The abundance and charge-state data are consistent with a gradual shock-accelerated SEP event. A type II radio burst was observed at the same time the shock front was detected by UVCS.
- Ultraviolet Detection and Detectors