Is the enhancement of type Ⅱ radio bursts during CME interactions related to the associated solar energetic particle event?

作     者：Liu-Guan Ding Zhi-Wei Wang Li Feng Gang Li Yong Jiang 

作者机构：School of Physics and Optoelectronic EngineeringNanjing University of Information Science and Technology Institute of Space WeatherNanjing University of Information Science and Technology Key Laboratory of Dark Matter and Space AstronomyPurple Mountain ObservatoryChinese Academy of Sciences Department of Space Science and CSPARUniversity of Alabama in Huntsville 

出 版 物：《Research in Astronomy and Astrophysics》 (天文和天体物理学研究（英文版）)

年 卷 期：2019年第19卷第1期

页      面：47-60页

核心收录：

学科分类：070802[理学-空间物理学] 07[理学] 0708[理学-地球物理学] 070401[理学-天体物理] 0704[理学-天文学] 

基　　金：supported at NUIST by the National Natural Science Foundation of China (NSFC) (Grant Nos. U1731105 and 41304150) the Natural Science Foundation of Jiangsu Province of China (No. BK20171456) sponsored also by the Qing Lan Project of Jiangsu Province for L.G. Ding (2016) supported by NSFC (Grant Nos.11522328, 11473070 and 11427803) the Youth Innovation Promotion Association the specialized research fund from the State Key Laboratory of Space Weather for financial support 

主　　题：Sun:coronal mass ejections(CMEs) Sun:radio radiation Sun:particle emission Sun:CME interaction 

摘      要：We investigated 64 pairs of interacting-CME events identified from simultaneous observations by the SOHO and STEREO spacecraft from January 2010 to August 2014, to examine the relationship between large SEP events in the energy range of ～25 to～60 MeV and properties of the interacting *** found that during CME interactions, the large SEP events in this study were all generated by CMEs with the presence of enhanced type Ⅱ radio bursts, which also have wider longitudinal distributions compared to events without a type Ⅱ radio burst or its enhancement(almost always associated with small SEP events).It seems that the signature of type Ⅱ radio burst enhancement is a good discriminator between large SEP and small or no SEP event producers during CME interactions. The type Ⅱ radio burst enhancement is more likely to be generated by CME interactions, with the main CME having a larger speed(v), angular width(WD), mass(m) and kinetic energy(Ek), and taking over the preceding CMEs. The preceding CMEs in these instances have higher v, WD, m and Ekthan those in CME pairs missing type Ⅱ radio bursts or enhancements. Generally, the values of these properties in the type-Ⅱ-enhanced events are typically higher than the corresponding non-type-Ⅱ or non-type-Ⅱ-enhanced cases for both the main and preceding CMEs. Our analysis also revealed that the intensities of associated SEP events correlate negatively with the intersection height of the two CMEs. Moreover, the overlap width of two CMEs is typically larger in type-Ⅱ-enhanced events than in non-type-Ⅱ or non-type-Ⅱ-enhanced events. Most type-Ⅱ-enhanced events and SEP events are coincident and are almost always made by the fast and wide main CMEs that sweep fully over relatively slower and narrower preceding CMEs. We suggest that a fast CME with enough energy completely overtaking a relatively narrower preceding CME, especially at low height, can drive a more energetic shock signified by the enhanced type Ⅱ radio bursts. The shock m