γ線爆発の深部にある非常に高エネルギー成分
H Abdalla1, R Adam2, F Aharonian3,4,5
1Centre for Space Research, North-West University, Potchefstroom, South Africa.
Nature
|November 22, 2019
まとめ
ガンマ線爆発 (GRB) からの非常に高エネルギー放射は,後発光段階の深部で検出されました. この発見は既存のモデルに 異議を唱えており 逆コンプトン放射は これらのエネルギーに満ちた宇宙爆発からの 遅い時の放射を 説明するかもしれないと示唆しています
科学分野:
- 天体物理学
- 高エネルギー天体物理学
- 宇宙の爆発
背景:
- ガンマ線爆発 (GRB) は 宇宙で最もエネルギッシュな爆発的な現象です
- GRBの放出には即発光と後発光が含まれており,後発光は徐々に明るさが低下する.
- GRBからの高エネルギー光子 (GeV) が検出されましたが,その起源と非常に高エネルギー (VHE) の放出は不明です.
研究 の 目的:
- ガンマ線爆発 (GRB) からの非常に高エネルギー (VHE) フォトンの起源を調査する.
- GRB 後発光期における VHE 放射線の原因となる放出機構を分析する.
主な方法:
- GRB 180720Bからの後発光期における非常に高エネルギー (VHE) 放射の観測.
- X線とガンマ線のエネルギー流と光子指数の分析
- 観測データと逆コンプトンとシンクロトロン放射の理論モデルの比較.
主要な成果:
- GRB 180720BからのVHE放射の検出 即時放射が終了してから10時間.
- 照明後のX線とガンマ線で比較可能なエネルギー流と光子指数を観測した.
- 逆コンプトン排出モデルは,遅い時間VHE排出のための粒子のエネルギー要求を軽減します.
結論:
- GRBの後発の深部でVHEの検出は,GRBの環境と放出メカニズムに重要な制約を与える.
- 逆コンプトン散布は VHE 放出の遅い時間の説明であり,粒子エネルギー需要を緩和します.
- この発見は,ガンマ線爆発の将来のVHE観測に重要な意味を持っています.
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