两次来自尘土充的地区的γ射线爆发,其中少有分子气体
B Hatsukade1, K Ohta2, A Endo3
1National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan.
Nature
|June 13, 2014
概括
长时间的马射线爆发发生在灰尘的地区,但令人惊的是,缺乏丰富的分子气体. 这表明大质量恒星可能在爆炸之前散发密集的气体,影响恒星形成环境.
科学领域:
- 天体物理学 天体物理学
- 宇宙恒星形成的宇宙恒星形成.
- 马射线爆炸天文学
背景情况:
- 长时间的马射线爆发 (GRBs) 起源于巨大的恒星爆炸,通常在具有分子气体的恒星形成区域中发现.
- 以前使用一氧化碳 (CO) 排放的研究未能在GRB宿主星系中检测到分子气体.
- 沿GRB后发光线的吸收中检测到的分子气体表明扩散云的特性,但并不代表一般环境.
研究的目的:
- 通过使用空间分辨率的观测,研究长时间GRB的直接环境中的分子气体和尘埃含量.
- 为了确定GRB宿主区域是否拥有预期的大质量恒星形成的分子气体储备.
主要方法:
- 对一氧化碳 (CO) 排放线进行了空间分辨率的观测.
- 进行毫米波长连续观测以追踪尘埃.
- 分析了来自两个星系的数据,其中有长时间的马射线爆发.
主要成果:
- 观测到的GRB的区域富含尘埃,但显著缺乏显著的分子气体.
- 与典型的恒星形成区域相比,分子气体与尘埃的比例较低 (<9-14).
- 这些发现与在巨大的恒星形成和爆炸的环境中大量分子气体的预期形成鲜明对比.
结论:
- 低分子气体与尘埃的比率表明,恒星形成所需的密集气体可能在GRB环境中被耗尽.
- 大质量恒星可能会通过反机制在它们最终爆炸性灭亡之前消散周围的分子气体.
- 这挑战了GRBs仅与原始,富含气体的恒星形成区域的简单关联.
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