高エネルギースペクトル成分を持つガンマ線爆発は,シンクロトロンショックモデルと矛盾しています
M M González1, B L Dingus, Y Kaneko
1Physics Department, University of Wisconsin, Madison, Wisconsin 53706, USA. magda@whopper.lanl.gov
Nature
|August 15, 2003
まとめ
新しい高エネルギーガンマ線成分が,1994年のガンマ線爆発 (GRB) で観測されました. この発見は標準モデルに異議を唱え,GRBにおける新しい粒子加速や陽子-光子相互作用を示唆している.
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:
- ガンマ線爆発 (GRB) は,宇宙で最もエネルギッシュな現象です.
- GRBは,エネルギーの大半を光子 (30 keV MeV) として放出し,エネルギーが低い後光を放ちます.
- 標準モデルでは,GRBの放射は,衝撃加速電子からのシンクロトロン放射に起因する.
研究 の 目的:
- GRBの特定の高エネルギースペクトルコンポーネントの観測を報告する.
- GRBの標準シンクロトロンショックモデルからの偏差を調査する.
主な方法:
- 1994年10月17日のガンマ線爆発の観測.
- 高エネルギー (複数-MeV) フォトンのスペクトル分析.
- 観測データを標準相対性ショックモデルと比較.
主要な成果:
- 異なる高エネルギー (マルチ-MeV) のスペクトル成分が観察され,低エネルギーガンマ線と異なる.
- 高エネルギーコンポーネントは,より遅いフクロス崩壊とより大きな流動性を示した.
- このコンポーネントは ~200 MeV (光子指数 ~ -1) までの功率法則に従った.
結論:
- 観測された高エネルギーコンポーネントは,GRBの標準シンクロトロンショックモデルに挑戦しています.
- 代替的な非熱電子プロセスなど,新しい現象が関与している可能性があります.
- 陽子-光子相互作用は,観測された高エネルギー放射の潜在的な説明である.
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