太陽系近くの強い,非常に傾いた恒星間磁場です
M Opher1, F Alouani Bibi, G Toth
1George Mason University, 4400 University Drive, Fairfax, Virginia 22030, USA. mopher@gmu.edu
Nature
|December 25, 2009
まとめ
新しい測定により,局所的な恒星間磁場は,これまで考えられていたよりも強く (3.7-5.5マイクロG) 傾いていることが明らかになった. この発見は,太陽圏と銀河の磁場に関する私たちの理解に影響を与えます.
科学分野:
- 天体物理学 天体物理学
- プラズマ物理学 プラズマ物理学
- ヘリオフィジックス ヘリオフィジックス
背景:
- 銀河の進化を理解するために,ヘリオスフィアの近くの局所的な星間媒介 (ISM) の磁場の強さと方向性は極めて重要ですが,十分に制限されていません.
- ISMの磁場強度 (1.8-2.5マイクロG) と方向に関する以前の推定は,間接的な方法に基づいており,星間中性水素を完全に考慮していなかった.
研究 の 目的:
- ヘリオスフィアの近くにある恒星間媒体の磁場の強さと方向を決定する.
- 地元のISMとヘリオスフィアの相互作用のモデルを精錬する.
主な方法:
- 太陽風のプラズマの流れの傾斜をヘリオシートで測定する.
- ヘリオスフィア内の宇宙船の観測データを利用する.
主要な成果:
- 地元のISMの磁場強度は3.7~5.5マイクロGの間で推定されている.
- 磁場は,星間媒体の流動方向から約20〜30度傾いている.
- 磁場は,銀河平面に対して約30度方向に傾いている.
結論:
- 太陽の周辺の恒星間磁場は,これまで考えられていたよりもかなり強い.
- フィールドの方向性は,それが渦巻またはヘリオスフィアの近くで歪んだ可能性があることを示唆しています.
- これらの発見は,ヘリオスフィアのモデルと,地元の銀河環境との相互作用を改訂することを必要としています.
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