천문학회보 (The Bulletin of The Korean Astronomical Society)
- 제44권2호
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- Pages.41.3-41.3
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- 2019
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- 1226-2692(pISSN)
Origin and formation mechanism of LASCO-C2 post CME blobs observed on 2017 September 10
- Lee, Jae-Ok (Korea Astronomy and Space Science Institute) ;
- Cho, Kyung-Suk (Korea Astronomy and Space Science Institute) ;
- Lee, Kyoung-Sun (Center for Space Plasma and Aeronomic Research, University of Alabama in Huntsville)
- 발행 : 2019.10.14
초록
To find out the origin and formation mechanism of LASCO-C2 post-CME blobs, we investigate 2 LASCO-C2 blobs and 35 low corona blobs observed by K-Cor on 2017 September 10 from 17:11 to 18:58 UT. By visual inspection of a post-CME ray and the locations of low corona blobs in K-Cor and LASCO-C2 images with examining the time-height data of all blobs, we find the following results: (1) The post-CME ray structure is well identified in the K-Cor images than LASCO-C2 ones. (2) Low corona blobs can be classified into two groups according to their formation mechanisms: 27 blobs belong to Group 1, generated by the tearing mode instability near the middles of current sheets as described by Furth et al., 1963; Shibata & Tanuma, 2001; Shen et al., 2011, the others belong to Group 2, formed by the tearing mode instability near the tips of current sheets as shown in Figure 5 of Sitnov et al., 2002. (3) Group 1 has low initial appearance heights <1.30 Rs>, broad speed range (38 ~ 945 km/s), and high accelerations <4,272 m/s2 > than Group 2, which has initial appearance heights <1.72 Rs>, speed range (579 ~ 843 km/s), and accelerations <1,413 m/s2 >. (4) among 8 blobs for Group 2, only 2 blobs are temporally and spatially associated with 2 LASCO-C2 ones and their initial observation heights are 1.93 and 1.79 Rs, respectively. Our results firstly demonstrate that LASCO-C2 blobs form the heights from about 1.7 to 2.0 Rs and they are generated by the tearing mode instability near the tips of current sheets.
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