$r$-过程作为致密天体并合产生镧系元素的过程
$r$-Process as Production of Lanthanides from Compact Object Mergers
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中文总结 AI 辅助
本文通过端到端模拟研究双中子星与黑洞-中子星并合对$r$-过程元素增丰的贡献，发现镧系元素主要由双中子星并合产生，且丰度对状态方程和黑洞自旋不敏感。
中文摘要 AI 辅助
双中子星（BNS）并合与黑洞-中子星（BH-NS）并合对银河系中快速中子俘获过程（$r$-过程）元素增丰的相对贡献，在核天体物理学中仍是一个悬而未决的问题。本文中，我们分别利用致密天体并合群体天体物理与统计学（COMPAS）代码、SkyNet网络以及一个随机多区模型，开展了双星群体合成、核合成以及银河系化学演化（GCE）的端到端数值模拟。通过考虑五种中子星（NS）状态方程（EOS）以及BNS和BH-NS并合中不同的黑洞自旋，我们发现平均丰度似乎并不显著依赖于NS的状态方程以及BNS和BH-NS并合中黑洞的自旋。对于给定的NS状态方程，在第二峰之前（质量数$A\sim$130），BNS的丰度高于BH-NS并合，但当质量数大于130时，BNS的丰度则较低。此外，较轻的$r$-过程元素（$A<$130）主要由吸积盘风产生，而较重的元素（$A>$130）则主要来源于动力学抛射物。另一方面，纯BNS并合是银河系化学演化后期镧系元素（如铕（Eu））产生的主要贡献者，而BH-NS并合对银河系中$\rm Eu/Fe$演化轨迹中重$r$-过程元素的贡献很小。
英文摘要
The relative contributions of binary neutron star (BNS) and black hole-neutron star (BH-NS) mergers to the Galactic enrichment from the rapid neutron-capture process ($r$-process) remain an open question in nuclear astrophysics. In this paper, we present end-to-end numerical simulations of binary population synthesis, nucleosynthesis, and Galactic chemical evolution (GCE) via Compact Object Mergers Population Astrophysics and Statistics (COMPAS), SkyNet network, and a stochastic multi-zone model, respectively. By considering five equations of state (EOS) of NS and different spins of BH for BNS and BH-NS mergers, it is found that the averaged abundance seems not to be significantly dependent on the EOS of NS and spin of BH for BNS and BH-NS mergers. For given EOSs of NS, the abundance of BNS is higher than that of BH-NS mergers before the second peak (for mass number $A\sim$130), but it is lower when the mass number is greater than 130. Moreover, the lighter $r$-process elements ($A<$130) are predominantly produced by the disk wind, while the heavier elements ($A>$130) originate mainly from the dynamical ejecta. The purely BNS mergers, on the other hand, are the dominant contributors to the production of lanthanides like europium (Eu) at the later stage of GCE, but BH-NS mergers make only a small contribution of heavy $r$-process elements for the $\rm Eu/Fe$ evolutionary tracks in the Milky Way.
发表机构
- Guangxi University（广西大学）
机构由 AI 辅助整理，请以论文原文为准。
