フェルミ LATによって明らかにされた超新星残骸W44の殻からのガンマ線放射
A A Abdo1, M Ackermann, M Ajello
1Space Science Division, Naval Research Laboratory, Washington, DC 20375, USA.
Science (New York, N.Y.)
|January 9, 2010
まとめ
W44のような超新星残骸は,宇宙線を加速し,ガンマ線放射を生成します. 観測により,陽子と原子核が原点であると確認され,宇宙における粒子加速に関する洞察が提供されました.
科学分野:
- 天体物理学 天体物理学
- 高エネルギー天体物理学
- 宇宙線物理学 宇宙線物理学
背景:
- 超新星残留物 (SNRs) は,宇宙線を非常に高いエネルギーまで加速させると仮定されています.
- SNRから観測された放出の原因となる特定の粒子は,未だに特定されていない.
研究 の 目的:
- SNR W44.4からの高エネルギー放射の起源を調査する.
- SNRでガンマ線を発生させる粒子を特定する.
- 粒子加速機構とその環境依存性を探求する.
主な方法:
- フェルミ大望遠鏡を用いたSNR W44の観測.
- 2 x 10^8から3 x 10^11電子ボルトのエネルギー範囲のガンマ線スペクトルの分析.
- ガンマ線源とSNRシェルの形態学的比較.
主要な成果:
- SNR W44シェルと空間的に一致するガンマ線源の検出.
- ガンマ線スペクトルは,陽子や原子核からの放射によってよくモデル化されています.
- 約10^9電子ボルト以上で観測されたスペクトルの鋭さ.
結論:
- SNR W44からのガンマ線放射は,残骸の中で加速した粒子によって生成されます.
- 陽子と原子核は,この放射の発生源である可能性が高い.
- スペクトルの特徴は,密度の高い環境における粒子の加速と,それらの星間空間への放出についての洞察を提供します.
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