TRENDS IN 44Ti AND 56Ni FROM CORE-COLLAPSE SUPERNOVAE
TRENDS IN 44Ti AND 56Ni FROM CORE-COLLAPSE SUPERNOVAE
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核心塌陷超新星中 44Ti 和 56Ni 的趋势
DOI：
10.1088/0067-0049/191/1/66
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发表时间：
2010
期刊：
影响因子：
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通讯作者：
M. Wiescher
中科院分区：
文献类型：
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作者：
G. Magkotsios;F. Timmes;A. Hungerford;C. Fryer;P. Young;M. Wiescher
我们比较了从后处理的热力学轨迹从三个不同的核心崩溃模型-仙后座A祖，双冲击超新星祖，和旋转的二维爆炸的产量从指数和幂律轨迹的44 Ti和56 Ni的产量。在这些核心塌陷模型中达到的峰值温度和密度跨越了我们确定的几个不同的核合成区域，导致不同质量元素的44 Ti和56 Ni产率有不同的趋势。44 Ti和56 Ni的质量分数分布的指数和幂律的配置文件一般解释的趋势后处理的产量，这取决于哪些区域被遍历的模型。我们发现，从指数和幂律轨迹的44 Ti和56 Ni的综合产量一般是在一个因素的两个或更少的后处理产量。我们还分析了特定核反应对44 Ti和56 Ni丰度演化的影响。影响所有产率的反应是3α，p（e-，νe）n和。其余反应根据它们对44 Ti合成的影响程度进行排序。44 Ti（α，p）47 V，40 Ca（α，γ）44 Ti，45 V（p，γ）46 Cr，40 Ca（α，p）43 Sc，17 F（α，p）20 Ne，21 Na（α，p）24 Mg，41 Sc（p，γ）42 Ti，43 Sc（p，γ）44 Ti，44 Ti（p，γ）45 V，57 Ni（p，γ）58 Cu，沿着着有许多弱反应。我们的分析表明，并不是所有的44 Ti都需要在核心坍塌事件中富含α的冻结中产生，并且反应速率平衡与膨胀曲线的时标效应相结合可能解释了超新星遗迹中观察到的44 Ti的缺乏。
We compare the yields of 44Ti and 56Ni produced from post-processing the thermodynamic trajectories from three different core-collapse models—a Cassiopeia A progenitor, a double shock hypernova progenitor, and a rotating two-dimensional explosion—with the yields from exponential and power-law trajectories. The peak temperatures and densities achieved in these core-collapse models span several of the distinct nucleosynthesis regions we identify, resulting in different trends in the 44Ti and 56Ni yields for different mass elements. The 44Ti and 56Ni mass fraction profiles from the exponential and power-law profiles generally explain the tendencies of the post-processed yields, depending on which regions are traversed by the model. We find that integrated yields of 44Ti and 56Ni from the exponential and power-law trajectories are generally within a factor two or less of the post-process yields. We also analyze the influence of specific nuclear reactions on the 44Ti and 56Ni abundance evolution. Reactions that affect all yields globally are the 3α, p(e−, νe)n and . The rest of the reactions are ranked according to their degree of impact on the synthesis of 44Ti. The primary ones include 44Ti(α, p)47V, 40Ca(α, γ)44Ti, 45V(p, γ)46Cr, 40Ca(α, p)43Sc, 17F(α, p)20Ne, 21Na(α, p)24Mg, 41Sc(p, γ)42Ti, 43Sc(p, γ)44Ti, 44Ti(p, γ)45V, and 57Ni(p, γ)58Cu, along with numerous weak reactions. Our analysis suggests that not all 44Ti need to be produced in an α-rich freeze-out in core-collapse events, and that reaction rate equilibria in combination with timescale effects for the expansion profile may account for the paucity of 44Ti observed in supernova remnants.