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ヘリオスフィアの終結衝撃の近くにあるエネルギー粒子増強
Frank B McDonald1, Edward C Stone, Alan C Cummings
1Institute for Physical Science and Technology, University of Maryland, College Park, Maryland 20742, USA. fm27@umail.umd.edu
Nature
|November 7, 2003
まとめ
ボイジャー1号は,太陽圏の近くで,宇宙線を含むエネルギー粒子の大幅な増加を検出しました.
科学分野:
- 宇宙物理学 宇宙物理学
- ヘリオフィジックス ヘリオフィジックス
- 宇宙線物理学 宇宙線物理学
背景:
- ヴォイジャー1号は85天文学単位 (au) を超えた遠くのヘリオスフィアを探査しています.
- ターミネーションショックは,超音速太陽風が減速する重要な境界線です.
- この領域では,様々なエネルギー粒子が加速すると予想されます.
研究 の 目的:
- ヴォイジャー1号によって観測されたエネルギー粒子のユニークな増加を報告し,分析するためです.
- これらの観測をヘリオスフィアの構造と粒子加速の文脈で解釈する.
主な方法:
- ヴォイジャー1号からのエネルギーイオンと電子データの分析.
- 観測された粒子集団と,ヘリオスフィアの理論的予想を比較する.
主要な成果:
- 2002年半ばから7ヶ月間持続したエネルギーイオンと電子の増加が観察されました.
- このイベントは,銀河の宇宙線,異常な宇宙線,低エネルギーイオンの同時上昇を示した.
- 異常な宇宙線特性は,ボイジャー1号がまだ終結ショックに達していないことを示唆しています.
結論:
- 観測された粒子の増加は,終止ショックに到達する前駆体イベントとして解釈されます.
- 宇宙線の低い放射性アニソトロピーは,フォアショックの領域の位置を支えている.
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