遠いクエーサーからの非常に高エネルギーのガンマ線:宇宙はどのくらい透明ですか?
まとめ
MAGIC望遠鏡は,遠いクエーサー3C 279からの非常に高エネルギーガンマ線を検出し,そのような放射線を発する観測された最も遠い物体をマークしました. この発見は,宇宙における分散した背景光のレベルが低いことを示唆している.
科学分野:
- * 天文学と天体物理学
- *高エネルギーガンマ線天文学
背景:
- *準恒星放射源 (クエザール) は,電磁スペクトル全体にわたって放射線を放射することが知られている活発な銀河核です.
- * 遠い物体からの非常に高エネルギー (VHE) ガンマ線を検出することは,銀河外背景光 (EBL) によって吸収される可能性があるため,困難です.
研究 の 目的:
- * 低値ガンマ望遠鏡を使用して,遠いクエーサーからのVHEガンマ線放射を検出する.
- * VHEガンマ線伝播に基づく銀河外背景光の性質を調査する.
主な方法:
- * 大気ガマ画像チェレンコフ望遠鏡 (MAGIC) を利用し,低エネルギー値観測に最適化しました.
- *クワザール3C 279の巨大なフレアからのガンマ線信号を観測・分析した.
主要な成果:
- *0.536の赤偏移 (5億光年以上の距離) に位置するクエーサー3C279からのVHEガンマ線を成功裏に検出しました.
- * これは50ギガ電子ボルト (GeV) 以上でガンマ線を放射する,これまでに検出された最も遠い物体を表しています.
- *観測結果は,銀河外背景光の密度が予想より低いことを示唆している.
結論:
- * 3C 279からのVHEガンマ線の検出は,観測可能なガンマ線天文学の境界を前例のない距離へと押し広げています.
- *推論された低EBL密度は,銀河数から得られた推定値と一致し,独立した証拠を提供しています.
- * この研究は,現在のガンマ線望遠鏡が,遠い宇宙とその間接する放射線場を探査する能力を実証しています.
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