日本地球惑星科学連合2023年大会

講演情報

[E] オンラインポスター発表

セッション記号 P (宇宙惑星科学) » P-EM 太陽地球系科学・宇宙電磁気学・宇宙環境

[P-EM14] Frontiers in solar physics

2023年5月24日(水) 10:45 〜 12:15 オンラインポスターZoom会場 (2) (オンラインポスター)

コンビーナ:鳥海 森(宇宙航空研究開発機構 宇宙科学研究所)、横山 央明(京都大学大学院理学研究科)、今田 晋亮(東京大学理学系研究科地球惑星科学専攻)、Sterling Alphonse(NASA/MSFC)

現地ポスター発表開催日時 (2023/5/23 17:15-18:45)

10:45 〜 12:15

[PEM14-P02] Quantitative study of pitch angle distribution through microwave fast propagation in a solar flare observed with Nobeyama Radioheliograph

*松本 圭太郎1増田 智1岩井 一正1金子 岳史2簑島 敬3 (1.名古屋大学宇宙地球環境研究所 、2.ロッキード・マーティン太陽天体物理学研究所 、3.海洋研究開発機構 数理科学・先端技術研究開発センター )


キーワード:太陽フレア、マイクロ波放射

The mechanism of particle acceleration during solar flares still remains controversial in solar physics. The pitch angle distribution of the accelerated electrons represents an important element in understanding this mechanism. Electrons that are accelerated to nearly relativistic speeds emit non-thermal microwaves. By using the Nobeyama Radioheliograph (NoRH), [Yokoyama+2002] estimated the pitch angle of accelerated electrons by analyzing the propagation velocity of non-thermal microwave sources. We found another flare event (an M-class flare on October 22, 2014) that showed similar observational features and evaluated the pitch angle of the accelerated electrons through multi-wavelength observations with NoRH, SDO, and Fermi, and computer simulations with the coronal magnetic field obtained from the NLFFF model. Finally, we concluded that electron injection took place toward one footpoint of the loop and also obtained results indicating a bouncing motion of the injected electrons along the magnetic loop (submitted to ApJL).

This presentation will undertake a theoretical examination of the position and pitch angle distribution of injected electrons within the loop. By solving the Fokker-Plank equation, we will determine the phase space density with pitch angle and energy as independent variables in an 1D coordinate system along the magnetic loop, as determined by the NLFFF model. This will allow us to investigate the bouncing motion of electrons along the loop. The time-varying 17 GHz microwave emission along the loop will be determined through the solution of the Fokker-Plank equation. Our results indicate that electron injection occurred in the direction of the footpoint on one side. We will also employ this method to conduct a comprehensive survey of the parameters affecting the injection position and pitch angle distribution of accelerated electrons, and compare the results to observations, with a focus on discussing the injection of accelerated electrons in this event.