Astronomy and Astrophysics – Astrophysics – Solar and Stellar Astrophysics
Scientific paper
2011-12-20
Astronomy and Astrophysics
Astrophysics
Solar and Stellar Astrophysics
13 pages, 4 figures, accepted for publication in The Astrophysical Journal Letters
Scientific paper
We address the nature of EUV waves through direct observations of the formation of a diffuse wave driven by the expansion of a coronal mass ejection (CME) and its subsequent separation from the CME front. The wave and the CME on 2011 June 7 were well observed by Atmospheric Imaging Assembly onboard Solar Dynamic Observatory. Following the solar eruption onset, marked by the beginning of the rapid increasing of the CME velocity and the X-ray flux of accompanying flare, the CME exhibits a strong lateral expansion. During this impulsive expansion phase, the expansion speed of the CME bubble increases from 100 km s$^{-1}$ to 450 km s$^{-1}$ in only six minutes. An important finding is that a diffuse wave front starts to separate from the front of the expanding bubble shortly after the lateral expansion slows down. Also a type-II burst is formed near the time of the separation. After the separation, two distinct fronts propagate with different kinematic properties. The diffuse front travels across the entire solar disk; while the sharp front rises up, forming the CME ejecta with the diffuse front ahead of it. These observations suggest that the previously termed EUV wave is a composite phenomenon and driven by the CME expansion. While the CME expansion is accelerating, the wave front is cospatial with the CME front, thus the two fronts are indiscernible. Following the end of the acceleration phase, the wave moves away from the CME front with gradually an increasing distance between them.
Cheng Xiande
Ding Ming-De Ding
Liu Ya-Ying
Olmedo Oscar
Vourlidas Angelos
No associations
LandOfFree
Investigation of the Formation and Separation of An EUV Wave from the Expansion of A Coronal Mass Ejection does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Investigation of the Formation and Separation of An EUV Wave from the Expansion of A Coronal Mass Ejection, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Investigation of the Formation and Separation of An EUV Wave from the Expansion of A Coronal Mass Ejection will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-54391