Three‐dimensional Structure of the 2002 April 21 Coronal Mass Ejection

J.‐Y. Lee, J. C. Raymond, Y.‐K. Ko, K.‐S. Kim
2006 Astrophysical Journal  
A three-dimensional reconstruction of the 2002 April 21 partial halo Coronal Mass Ejection (CME) has been made based on the O vi 1032 8 and [ Fe xviii] 974 8 lines observed by the Ultraviolet Coronagraph Spectrometer ( UVCS) on board the Solar and Heliospheric Observatory (SOHO). We use the Doppler velocities to derive the CME structure along the line of sight. UVCS observed the O vi line profiles split into strongly Doppler red-and blueshifted components, and the region of split profiles grew
more » ... plit profiles grew rapidly along the long spectrograph slit. The more localized [Fe xviii] bright emission starts at the same time as the maximum Doppler redshift of O vi, indicating that it is inside the CME. In the view from the solar west, the O vi looks like halo CMEs seen by the Large Angle and Spectrometric Coronagraph (LASCO). The [ Fe xviii] bright emission appears as a barlike structure seen nearly end-on from the Earth, and side-on from the solar north and from solar west. The reconstructed [Fe xviii] emission allows two interpretations, as ejection of preexisting hot plasma or as a current sheet. The evidence favors the current sheet interpretation, although we cannot rule out the alternatives.
doi:10.1086/506981 fatcat:74zp6imtfvbvbbirozfcx7r5ba