8%的莱曼连续光子从一个紧的形成恒星的矮星系泄漏
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
概括
低质量星系是宇宙再电离的关键. 观测显示附近的恒星形成星系,J0925+1403,正在泄漏电离辐射,这表明这些星系可以电离星系间介质.
科学领域:
- 宇宙再离子化
- 观测宇宙学
- 银河系的演变
背景情况:
- 在宇宙"黑暗时代"之后,宇宙的再离子化是宇宙学的一个主要问题.
- 低质量,恒星形成的星系被假设为电离辐射的主要来源.
- 直接观察高红移星系是一项挑战,需要对当地的代理星系进行研究.
研究的目的:
- 确定可以作为宇宙再电离源的代理星系群体.
- 为了研究离子辐射的逃生分数来自附近的低质量恒星.
主要方法:
- 附近的低质量恒星形成星系J0925+1403的远紫外观测.
- 对电离辐射泄漏和逃逸部分的分析.
主要成果:
- 星系J0925+1403的离子辐射逃逸率很大,约为8%.
- 这种逃逸率高于以前在类似的低红移星系 (1-3%) 中观察到的.
- 发射的光子足以电离比银河系本身更大质量的星际介质物质.
结论:
- 附近的低质量恒星形成星系,如J0925+1403,能够对宇宙的再离子化做出重大贡献.
- 观察到的高逃逸率支持这样的星系是电离辐射的主要来源的假设.
- 对这些本地类型的进一步研究对于理解再离子化时代至关重要.
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