狭い,星を形成する矮星銀河からライマン連続体の光子の8パーセントの漏れ
Y I Izotov1, I Orlitová2, D Schaerer3,4
1Main Astronomical Observatory, National Academy of Sciences of Ukraine, 27 Zabolotnoho street, Kyiv 03680, Ukraine.
Nature
|January 15, 2016
まとめ
低質量銀河は 宇宙の再イオン化の鍵です 観測により,近くの恒星形成銀河である J0925+1403 が電離放射線を放出しており,これらの銀河が銀河間媒体を電離することが示唆されています.
科学分野:
- 宇宙再イオン化
- 観測宇宙学
- 銀河の進化
背景:
- 宇宙の再イオン化は 宇宙学における大きな問題です
- 低質量で恒星を形成する銀河は,電離放射線の主な源であると考えられています.
- 高赤偏移の銀河を直接観測するのは難しいので ローカルプロキシを研究する必要がある.
研究 の 目的:
- 宇宙再イオン化の源として役立つ 局所的な銀河群を特定する
- 近くの低質量恒星系からの電離放射線の 脱出分子を調査するためです
主な方法:
- 近くの低質量恒星形成銀河J0925+1403の遠紫観測
- 離子放射線の漏れと脱出分子の分析
主要な成果:
- J0925+1403の銀河は,約8%の電離放射線の大幅な脱出率を示しています.
- この脱出分数は,似たような低赤偏移銀河 (1-3%) で以前に観測されたより高い.
- 放射される光子は銀河間媒体の物質を イオン化するのに十分で 銀河自身よりも 大きく質量があります
結論:
- J0925+1403のような近隣の低質量恒星系は,宇宙の再イオン化に大きく貢献できる.
- 観測された高い脱出分数は,そのような銀河が電離放射線の主な源であるという仮説を支持する.
- これらの局所的なアナログのさらなる研究は,再イオン化の時代を理解するために不可欠です.
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