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噴火中の矮星新星における一時的な無線ジェット
Elmar Körding1, Michael Rupen, Christian Knigge
1School of Physics and Astronomy, University of Southampton, Southampton SO17 1BJ, UK. elmar@phys.soton.ac.uk
Science (New York, N.Y.)
|June 7, 2008
まとめ
天文学者は,白矮星の一種である新矮星からの最初の天体物理ジェットを検出しました. この発見は,ディスク/ジェットカップリングメカニズムが,すべての集積する天体に共通していることを示唆しています.
科学分野:
- 天体物理学 天体物理学
- 恒星の進化について
- プラズマ物理学 プラズマ物理学
背景:
- 天体物理学的なジェットは,超大質量ブラックホールや若い恒星物体など,様々な増加する天体で観測されています.
- 主にX線バイナリに基づいた統一されたディスク/ジェットカップリングシナリオは広く受け入れられています.
- 壊滅的な変数,特に矮星新星 (弱く収縮する白矮星) は,X線バイナリー星に似た爆発行動にもかかわらず,検出されたジェットがないため,例外とみなされた.
研究 の 目的:
- 矮星新星における天体物理ジェットの存在を調査する.
- 他の集積する天体で見られる円盤/ジェット結合メカニズムが,矮星新星にも存在するかどうかを判断する.
- ジェット生成が,増加系における至る所に存在する現象であるという仮説を検証する.
主な方法:
- アウトバースト・フェーズ中の小惑星新星に関する無線観測を行った.
- 観測された無線放射を,ジェットからのシンクロトロン放射を示す特性について分析した.
- 推論されたジェット (パワー,アウトバーストサイクルとの関係) の性質を,X線バイナリで観測されたものと比較した.
主要な成果:
- アウトバースト中の矮星新星からの変数フラットスペクトルの無線放射が検出されました.
- ラジオ発射を一時ジェットから発生したものと解釈し,シンクロトロン発射と一致した.
- 推論されたジェットパワーと噴出サイクルとの関係は,X線バイナリーのそれと類似していることがわかりました.
結論:
- 矮星新星におけるジェットの検出は,これらのシステムがジェット生成の例外であるという考えに異議を唱える.
- この発見は,ディスク/ジェットカップリングメカニズムは,実に至るところに存在し,様々なアクレートする物体で動作していることを示唆している.
- この研究は,恒星質量の物体から超大質量ブラックホールまで,多様な天体物理環境におけるジェット形成の理解を統一しています.
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