在双中子恒星合并过程中的r过程核合成的光谱识别
E Pian1, P D'Avanzo2, S Benetti3
1INAF, Institute of Space Astrophysics and Cosmic Physics, Via Gobetti 101, I-40129 Bologna, Italy.
Nature
|November 3, 2017
概括
两个中子星的合并产生了明亮的千新星, 一个强大的事件产生像黄金和这样的重元素. 这个与GW170817相关的宇宙爆炸, 提供了关于核合成和宇宙元素工厂的见解.
科学领域:
- 天体物理学
- 核物理
- 宇宙学
背景情况:
- 理论上说,中子星的合并会产生短的马射线爆发,引力波和千新星.
- 千诺瓦是短暂的光近红外光源,由重元素合成 (r过程) 提供动力.
- 之前关于千新星的证据有限,在2017年观察到微弱的重新亮化.
研究的目的:
- 通过光谱识别和描述与GW170817和GRB 170817A相关的明亮千新星.
- 了解千诺瓦喷射物及其核合成产物的物理性质.
- 确认中子星合并在重元素的产生过程中的作用.
主要方法:
- 使用地面观测站的一系列光谱.
- 覆盖从紫外线到近红外线的波长范围.
- 将观察到的光谱特征与千诺瓦喷射的理论模型进行比较.
主要成果:
- 千新星呈现出快速膨胀的喷射物 (0.2c),在1.5天内达到50AU.
- 频谱特征表明在动态喷射和风区域中存在核合成产生的元素.
- 估计0.03-0.05太阳物质被抛出,包括化物.
结论:
- 观察到的千新星为中子星的融合提供了强有力的证据,
- 这项研究证实了与中子星融合相关的预测现象.
- 这些发现支持千诺瓦在合成黄金和等稀有元素中的作用.
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