3D hydrodynamic simulations of C ingestion into a convective O shell
3D hydrodynamic simulations of C ingestion into a convective O shell
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DOI：
10.1093/mnras/stz2952
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发表时间：
2018-08
影响因子：
4.8
通讯作者：
R. Andrassy;F. Herwig;P. Woodward;C. Ritter
中科院分区：
文献类型：
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作者：
R. Andrassy;F. Herwig;P. Woodward;C. Ritter
在进化的大质量恒星中，对流壳层之间的相互作用与超新星的仿制品有关，与奇z元素Cl， K和Sc的产生有关，它们也可能有助于产生大规模的非球面，这有助于超新星爆炸模型中的激波恢复。我们研究了c壳层物质摄取到对流o燃烧壳层的过程，包括摄取材料核燃烧的流体动力学反馈。我们的三维流体动力学模拟几乎跨越了总光度的3个指数。除一个模拟外，其余模拟均达到准平稳状态，夹带速率和对流速度分别与Ltot和L_\ mathm {tot}^{1/3}$成正比。碳燃烧提供$14\!-\！33{{\ \rm \ %}}$的总光度，取决于所考虑的反应集。在7683和11523网格上进行的等效模拟在数量上是非常一致的。气流以少数大尺度对流单体为主。在实验运行中，C燃烧产生的能量增加了10倍，导致马赫数超过0.2的大尺度振荡。这种运行最接近于剧烈的O-C壳层合并的预期条件，这是奇数- z元素（如K和Sc）的潜在生产场所，并且可能在超新星祖先中播下不对称的种子。一维模拟由于忽略了夹带物质的团块对核反应速率的影响，因此可能低估了摄取物质燃烧产生的能量，低估幅度高达1 / 2。
Interactions between convective shells in evolved massive stars have been linked to supernova impostors, to the production of the odd-Z elements Cl, K, and Sc, and they might also help generate the large-scale asphericities that are known to facilitate shock revival in supernova explosion models. We investigate the process of ingestion of C-shell material into a convective O-burning shell, including the hydrodynamic feedback from the nuclear burning of the ingested material. Our 3D hydrodynamic simulations span almost 3 dex in the total luminosity Ltot. All but one of the simulations reach a quasi-stationary state with the entrainment rate and convective velocity proportional to Ltot and $L_\mathrm{tot}^{1/3}$, respectively. Carbon burning provides $14\!-\!33{{\ \rm per\ cent}}$ of the total luminosity, depending on the set of reactions considered. Equivalent simulations done on 7683 and 11523 grids are in excellent quantitative agreement. The flow is dominated by a few large-scale convective cells. An instability leading to large-scale oscillations with Mach numbers in excess of 0.2 develops in an experimental run with the energy yield from C burning increased by a factor of 10. This run represents most closely the conditions expected in a violent O–C shell merger, which is a potential production site for odd-Z elements such as K and Sc and which may seed asymmetries in the supernova progenitor. 1D simulations may underestimate the energy generation from the burning of ingested material by as much as a factor 2 owing to their missing the effect of clumpiness of entrained material on the nuclear reaction rate.