OBSERVATIONAL EVIDENCE OF PARTICLE ACCELERATION ASSOCIATED WITH PLASMOID MOTIONS

Journal Article · Sat Sep 10 04:00:00 EDT 2016 · Astrophysical Journal

DOI:https://doi.org/10.3847/0004-637X/828/2/103· OSTI ID:22667437

Takasao, Shinsuke ^[1]; Asai, Ayumi; Shibata, Kazunari ^[2]; Isobe, Hiroaki ^[3]

---

1. Department of Physics, Nagoya University, Nagoya, Aichi 464-8602 (Japan)
2. Kwasan and Hida Observatories, Kyoto University, Yamashina, Kyoto 607-8471 (Japan)
3. Unit of Synergetic Studies for Space, Kyoto University, Yamashina, Kyoto 607-8471 (Japan)

We report a strong association between the particle acceleration and plasma motions found in the 2010 August 18 solar flare. The plasma motions are tracked in the extreme ultraviolet (EUV) images taken by the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory and the Extreme UltraViolet Imager (EUVI) on the Solar Terrestrial Relations Observatory spacecraft Ahead , and the signature of particle acceleration was investigated by using Nobeyama Radioheliograph data. In our previous paper, we reported that in EUV images many plasma blobs appeared in the current sheet above the flare arcade. They were ejected bidirectionally along the current sheet, and the blobs that were ejected sunward collided with the flare arcade. Some of them collided or merged with each other before they were ejected from the current sheet. We discovered impulsive radio bursts associated with such plasma motions (ejection, coalescence, and collision with the post flare loops). The radio bursts are considered to be the gyrosynchrotron radiation by nonthermal high energy electrons. In addition, the stereoscopic observation by AIA and EUVI suggests that plasma blobs had a three-dimensionally elongated structure. We consider that the plasma blobs were three-dimensional plasmoids (i.e., flux ropes) moving in a current sheet. We believe that our observation provides clear evidence of particle acceleration associated with the plasmoid motions. We discuss possible acceleration mechanisms on the basis of our results.

• OSTI ID: 22667437
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 828; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ACCELERATION
COALESCENCE
COLLISIONS
EXTREME ULTRAVIOLET RADIATION
MAGNETIC FIELDS
MAGNETIC RECONNECTION
PLASMA
PLASMOIDS
SHEETS
SOLAR FLARES
SPACE VEHICLES
SUN
THREE-DIMENSIONAL CALCULATIONS