The Intermediate r-process in Core-collapse Supernovae Driven by the Magneto-rotational Instability
The Intermediate r-process in Core-collapse Supernovae Driven by the Magneto-rotational Instability
复制标题
DOI：
10.3847/2041-8213/aa5dee
复制
发表时间：
2016-11
期刊：
影响因子：
--
通讯作者：
N. Nishimura;H. Sawai;T. Takiwaki;S. Yamada;Friedrich-Karl Thielemann
中科院分区：
文献类型：
--
作者：
N. Nishimura;H. Sawai;T. Takiwaki;S. Yamada;Friedrich-Karl Thielemann
基于磁转不稳定性(MRI)引起的一种新的爆炸机制，我们研究了磁转超新星中的r过程核合成。进行了一系列具有包括中微子加热在内的详细微观物理的轴对称磁流体力学模拟，对磁共振成像进行了数值解析。中微子加热占主导地位的爆炸，在磁场的增强下，显示出轻度富含中子的抛射物产生的核(即弱r过程)，而磁场较强的爆炸模型再现了类似太阳的r过程模式。在我们的模型中，更常见的丰度模式是在弱的和规则的r过程之间，产生较轻和中等质量的核。这些中间的r过程表现出不同的丰度分布，与r过程增强的贫金属星中的几种丰度模式相一致。在磁力驱动的喷流中，Eu喷射物的数量与早期星系化学演化的预测值一致。相比之下，以中微子加热为主的爆炸具有相当数量的Fe()和Zn，分别与普通超新星和超新星相当。这些结果表明，磁转超新星可以产生从铁族到r过程元素的广泛的重核，这取决于爆炸动力学。
We investigated r-process nucleosynthesis in magneto-rotational supernovae, based on a new explosion mechanism induced by the magneto-rotational instability (MRI). A series of axisymmetric magneto-hydrodynamical simulations with detailed microphysics including neutrino heating is performed, numerically resolving the MRI. Neutrino-heating dominated explosions, enhanced by magnetic fields, showed mildly neutron-rich ejecta producing nuclei up to (i.e., the weak r-process), while explosion models with stronger magnetic fields reproduce a solar-like r-process pattern. More commonly seen abundance patterns in our models are in between the weak and regular r-process, producing lighter and intermediate-mass nuclei. These intermediate r-processes exhibit a variety of abundance distributions, compatible with several abundance patterns in r-process-enhanced metal-poor stars. The amount of Eu ejecta in magnetically driven jets agrees with predicted values in the chemical evolution of early galaxies. In contrast, neutrino-heating dominated explosions have a significant amount of Fe ( ) and Zn, comparable to regular supernovae and hypernovae, respectively. These results indicate magneto-rotational supernovae can produce a wide range of heavy nuclei from iron-group to r-process elements, depending on the explosion dynamics.