Origin of the heavy elements in binary neutron-star mergers from a gravitational-wave event
Origin of the heavy elements in binary neutron-star mergers from a gravitational-wave event
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DOI：
10.1038/nature24453
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发表时间：
2017-11-02
期刊：
影响因子：
64.8
通讯作者：
Ramirez-Ruiz, Enrico
中科院分区：
文献类型：
--
作者：
Kasen, Daniel;Metzger, Brian;Ramirez-Ruiz, Enrico
比铁重的元素的宇宙起源长期以来一直不确定。理论模型（1-7）表明，在两颗中子星的剧烈合并中排出的物质可以在称为快速中子捕获（r-过程）核合成的过程中聚集成重元素，如金和铂。重元素同位素的放射性衰变被预测（8-12）为独特的热辉光（“千诺瓦”）提供动力。引力波源（13）GW 170817的电磁对应物的发现代表了第一次探测和仔细检查新合成的r过程元素样品的机会（14-18）。在这里，我们报告的模型，预测的电磁发射的kilonovae详细，并使质量，速度和组成的喷出物从观测中得出。我们比较模型的光学和红外辐射与GW 170817事件，认为所观察到的源是一个kilonova。我们推断喷出物中存在两种不同的成分，一种主要由轻元素（原子质量数小于140）组成，另一种主要由重元素（原子质量数大于140）组成。从GW 170817推断出的抛射质量和合并率意味着这种合并是宇宙中r过程产生的主导模式。
The cosmic origin of elements heavier than iron has long been uncertain. Theoretical modelling(1-7) shows that the matter that is expelled in the violent merger of two neutron stars can assemble into heavy elements such as gold and platinum in a process known as rapid neutron capture (r-process) nucleosynthesis. The radioactive decay of isotopes of the heavy elements is predicted(8-12) to power a distinctive thermal glow (a 'kilonova'). The discovery of an electromagnetic counterpart to the gravitational-wave source(13) GW170817 represents the first opportunity to detect and scrutinize a sample of freshly synthesized r-process elements(14-18). Here we report models that predict the electromagnetic emission of kilonovae in detail and enable the mass, velocity and composition of ejecta to be derived from observations. We compare the models to the optical and infrared radiation associated with the GW170817 event to argue that the observed source is a kilonova. We infer the presence of two distinct components of ejecta, one composed primarily of light (atomic mass number less than 140) and one of heavy (atomic mass number greater than 140) r-process elements. The ejected mass and a merger rate inferred from GW170817 imply that such mergers are a dominant mode of r-process production in the Universe.