終止ショックをヘリオシートに横切る:磁場
L F Burlaga1, N F Ness, M H Acuña
1NASA-Goddard Space Flight Center, Greenbelt, MD 20771, USA. Leonard.F.Burlaga@nasa.gov
Science (New York, N.Y.)
|September 24, 2005
まとめ
ヴォイジャー1号のデータは,94AUのターミネーションショックの横断を明らかにしています. 磁場強度は著しく増加し,予測から逸脱し,ヘリオシートにおけるガウス分布を示した.
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
- 惑星科学は惑星科学である.
背景:
- ヘリオスフィアは,太陽の磁場と太陽風が支配する広大な宇宙領域です.
- 終止ショックは,太陽風が急に減速する境界をマークします.
- ヴォイジャー1号のミッションは,ヘリオスフィアの外部の領域のインシット測定を行っています.
研究 の 目的:
- 磁場データを分析するために,ボイジャー1号がヘリオスフィアの終結ショックを横断した.
- ヘリオシートにおける磁場特性を特徴付けるために.
- パーカーのモデルのような理論的モデルと観測を比較する.
主な方法:
- ボーイジャー1号の搭載機器による磁場測定.
- 終結ショックにおける磁場強度の圧縮比の分析.
- ヘリオシェイダーの磁場データの統計分析,分布と方向を含む.
主要な成果:
- ヴォイジャー1号は,2004年12月16日ごろ,94AUで終結ショックを横断しました.
- 観測された磁場圧縮比は,ショック全体で3.05 ± 0.04でした.
- 平均ヘリオシート磁場強度は0.136 ± 0.035 nTで,パーカーのモデル予測の約4.2倍でした.
- ヘリオシート磁場は,一般的にパーカー螺旋に沿って太陽から遠ざかっています.
- 宇宙線の強度は,ヘリオシートにおける磁場強度の増加と相関する.
結論:
- ヘリオスフィアの終端衝撃は,惑星間磁場を著しく圧縮する.
- ヴォイジャー1号のデータは,パーカーのモデルによって予測されたより強いヘリオシート磁場を示しています.
- ヘリオシェアの磁場構造と宇宙線への影響は複雑で,さらなる研究が必要である.
関連する概念動画
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