一个千诺瓦作为引力波源的电磁对应物
S J Smartt1, T-W Chen2, A Jerkstrand3
1Astrophysics Research Centre, School of Mathematics and Physics, Queens University Belfast, Belfast BT7 1NN, UK.
Nature
|November 3, 2017
概括
双中子星的合并会产生引力波和千新星. 这些事件会抛出重元素,发出与r过程核合成相一致的电磁信号,证实它们在制造比铁更重的元素中的作用.
科学领域:
- 天体物理学
- 核天体物理学
- 引力波天文学
背景情况:
- 引力波最初是从二进制黑洞的合并中检测到的.
- 预计中子星的合并会产生GW并喷射放射性物质.
- 这种喷射出来的物质可以为称为千诺瓦的发光电磁信号提供能量.
研究的目的:
- 报告一个电磁瞬态与二进制中子星合并 (GW170817) 的观测.
- 模拟瞬态的物理参数并将其与理论的千诺瓦预测进行比较.
- 研究中子星合并产生的重元素的核合成起源.
主要方法:
- 观测NGC 4993星系的短暂事件,与GW170817的空间一致.
- 观察到的电磁辐射的物理建模,包括弹出的质量,不透明度,速度和电源.
- 用光谱分析识别元素组成并与r过程核合成预测进行比较.
主要成果:
- 检测到与GW170817空间一致的快速色的电磁瞬态 (千诺瓦) 和微弱的马射线爆发.
- 物理参数 (射出质量~0.04太阳质量,低不透明度,高速度) 基本上与蓝色千诺瓦的预测相匹配.
- 光线曲线的功率规律斜率 (-1.2 ± 0.3) 与来自r过程核素的放射性电源相一致.
- 光谱特征表明存在轻的r过程元素 (原子质量为90-140).
- 观察到的快速色和红色表明可能来自丰富的化物排泄物.
结论:
- 双中子恒星的合并会产生引力波和放射性发电的千新星.
- 这些合并被证实是重于铁的核合成元素的重要来源.
- 在这些宇宙事件中产生了重元素.
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