The Impact of Nuclear Reaction Rate Uncertainties on the Evolution of Core-collapse Supernova Progenitors
The Impact of Nuclear Reaction Rate Uncertainties on the Evolution of Core-collapse Supernova Progenitors
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DOI：
10.3847/1538-4365/aaa29b
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发表时间：
2018-02-01
影响因子：
8.7
通讯作者：
Couch, S. M.
中科院分区：
文献类型：
--
作者：
Fields, C. E.;Timmes, F. X.;Couch, S. M.
我们探索的核心坍缩超新星的祖先属性的热核反应速率的复合不确定性耦合的概率密度函数的反应速率提供的STARLIB反应速率库与梅萨恒星模型。我们发展了1000个模型的15 M（圆点）从前主序核心O-耗尽在太阳和太阳下的金属丰度为2000 Monte Carlo恒星模型。对于每个恒星模型，我们独立地同时采样665个热核反应速率，并将它们用于梅萨原位反应网络，该网络遵循从H-1到Zn-64的127种同位素。在这个框架下，我们调查的核心质量，燃烧寿命，成分和结构特性在五个不同的进化时期。在每个时期，我们测量每个属性的变化的概率分布函数，并计算每个采样反应速率的斯皮尔曼等级顺序相关系数，以确定哪个反应速率对每个属性的变化影响最大。我们发现，反应速率的不确定性的N-14（p，γ）O-15，三-α，C-12（α，γ）O-16，C-12（C-12，p）Na-23，C-12（O-16，p）Al-27，O-16（O-16，n）S-31，O-16（O-16，p）P-31和（16 O）（O-16，α）Si-28占主导地位的变化的性质调查。我们发现，在核反应速率的不确定性引起的变化增长与每个通过阶段的演变，并在核心H-，He-耗尽，他们是相当的幅度的变化引起的质量分辨率和网络分辨率的选择。然而，在核心的C-，Ne-和O-耗尽，反应速率的不确定性可以占主导地位的变化，导致不确定性的各种性质的恒星模型的演变向铁核塌缩。
We explore properties of core-collapse supernova progenitors with respect to the composite uncertainties in the thermonuclear reaction rates by coupling the probability density functions of the reaction rates provided by the STARLIB reaction rate library with MESA stellar models. We evolve 1000 models of 15M(circle dot) from the pre-main sequence to core O-depletion at solar and subsolar metallicities for a total of 2000 Monte Carlo stellar models. For each stellar model, we independently and simultaneously sample 665 thermonuclear reaction rates and use them in a MESA in situ reaction network that follows 127 isotopes from H-1 to Zn-64. With this framework we survey the core mass, burning lifetime, composition, and structural properties at five different evolutionary epochs. At each epoch we measure the probability distribution function of the variations of each property and calculate Spearman rank-order correlation coefficients for each sampled reaction rate to identify which reaction rate has the largest impact on the variations on each property. We find that uncertainties in the reaction rates of N-14(p, gamma)O-15, triple-alpha, C-12(alpha, gamma)O-16, C-12(C-12, p)Na-23, C-12(O-16, p)Al-27, O-16(O-16, n)S-31, O-16(O-16, p)P-31, and (16O)(O-16, alpha)Si-28 dominate the variations of the properties surveyed. We find that variations induced by uncertainties in nuclear reaction rates grow with each passing phase of evolution, and at core H-, He-depletion they are of comparable magnitude to the variations induced by choices of mass resolution and network resolution. However, at core C-, Ne-, and O-depletion, the reaction rate uncertainties can dominate the variation, causing uncertainty in various properties of the stellar model in the evolution toward iron core-collapse.