发表机构
Aster Scientific; Heidelberger Institut für Theoretische Studien; Monash University; Keele University; University of Tokyo; University of Geneva; Steward Observatory, University of Arizona（Aster Scientific; 海德堡理论研究所; 莫纳什大学; 基尔大学; 东京大学; 日内瓦大学; 亚利桑那大学斯图尔德天文台）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过三维模拟和RANS方程分析超新星前身星氧-氖壳层合并，揭示了对流区内嵌套的多层对流-反应结构及其湍流驱动的混合机制。
AI 中文摘要
对流-反应事件是恒星演化的阶段，其中湍流混合与核燃烧直接竞争，因为它们在对流区内的时标变得相似。在这些事件中，对流区结构由对流输运与各化学元素核燃烧之间复杂而动态的相互作用所塑造，等离子体流将夹带区域与燃烧层连接起来。在此，我们分析了一颗大质量前超新星中氧-氖壳层合并的三维流体动力学模拟。我们使用雷诺平均纳维-斯托克斯（RANS）平均场成分输运方程来研究所呈现的结构。我们发现，合并后的对流区发展出由湍流驱动的复杂混合结构，包含多个嵌套的对流-反应壳层，所有这些壳层都包含在单一对流区内。关键控制因素不仅包括平均分层和混合，还包括每个化学同位素所涉及的核反应的涌现集体行为。几乎所有层都显示出燃烧与混合之间的准稳态平衡。我们对各层进行分类，并与一维恒星演化代码的处理方法进行讨论和对比，突出了一些影响。
英文摘要
Convective-reactive events are phases of stellar evolution where turbulent mixing and nuclear burning directly compete, since their timescales become similar within convection zones. During these events the convection zone structure is shaped by a complex and dynamic interaction of convective transport and nuclear burning of individual chemical elements, with plasma streams connecting the entrainment regions with the burning layers. Here we analyse a 3D hydrodynamic simulation of an oxygen--neon shell merger in a massive pre-supernova star. We study the emergent structure using the Reynolds-Averaged Navier-Stokes (RANS) mean-field composition transport equation. We find that the merged convective zone develops a complex, turbulence-driven mixing structure of multiple nested convective-reactive shells, all contained within the single convection zone. Key controlling factors include not only the mean stratification and mixing, but also emergent collective behaviour of involved nuclear reactions for every chemical isotope. Almost all layers show a quasi-steady balance between burning and mixing. We categorise the various layers, and discuss/contrast with 1D stellar evolution code treatments, highlighting some implications.
