旅行者号测量了来自银河系的Lyman-α散辐射
Rosine Lallement1, Eric Quémerais, Jean-Loup Bertaux
1Galaxies, Etoiles, Physique, Instrumentation (GEPI), Observatoire de Paris, CNRS, Université Paris Diderot, Place Jules Janssen, Meudon, France. rosine.lallement@obspm.fr
概括
旅行者航天器探测到银河系的气莱曼-α (Lyα) 辐射,此前隐藏在太阳的光中. 这一突破有助于理解遥远星系中的恒星形成和辐射转移.
科学领域:
- 天文学和天体物理学
- 宇宙学的宇宙学是什么?
- 银河系天文学 银河系天文学
背景情况:
- 水素莱曼-α (Lyα) 辐射是星系中恒星形成的关键指标.
- 由于太阳的Lyα光 (H光) 的压倒性前景污染,以前没有发现银河系的Lyα辐射.
- 日球的边界会影响当地的Lyα辐射源.
研究的目的:
- 检测和描述来自银河系的扩散莱曼-α (Lyα) 辐射.
- 为了克服当地的H光照干扰的挑战.
- 为星系中的Lyα辐射转移模型提供观测约束.
主要方法:
- 在旅行者航天器上利用紫外线光谱仪,它们正在离开日球.
- 利用H光的减少干扰来更清晰地检测银河系Lyα.
- 从恒星形成区域测量了表面亮度和估计的Lyα逃逸分数.
主要成果:
- 成功检测到来自银河系的扩散Lyα辐射.
- 对附近恒星形成区域的表面亮度为3-4雷利.
- 从明亮的H II区域确定了约3%的Lyα逃逸分数,显示出高的空间变异性.
结论:
- 对银河系Lyα辐射的检测提供了一个新的观测基准.
- 这些发现将完善外星系Lyα辐射转移的理论模型.
- 了解Lyα发射对于解释星系进化和恒星形成速度至关重要.
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