Uncertainties in the production of p nuclides in thermonuclear supernovae determined by Monte Carlo variations
Uncertainties in the production of p nuclides in thermonuclear supernovae determined by Monte Carlo variations
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DOI：
10.1093/mnras/stx3033
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发表时间：
2017-11
影响因子：
4.8
通讯作者：
N. Nishimura;N. Nishimura;T. Rauscher;T. Rauscher;Raphael Hirschi;Raphael Hirschi;A. Murphy;G. Cescutti;G. Cescutti;C. Travaglio
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作者：
N. Nishimura;N. Nishimura;T. Rauscher;T. Rauscher;Raphael Hirschi;Raphael Hirschi;A. Murphy;G. Cescutti;G. Cescutti;C. Travaglio
起源于从伴星星星吸积物质的白色矮星爆炸的热核超新星被认为是产生p核素的场所。这种核是在爆炸过程中产生的，在富含来自先前强S处理的种子核的层中。这些种子主要通过光衰变反应转化为质子更丰富的同位素。在蒙特卡罗方法中使用了来自2D爆炸模型的数千个轨迹。温度依赖的不确定性被单独分配到数千个速率同时变化的后处理在一个扩展的核反应网络。确定了由于天体物理反应率的不确定性而引起的最终核丰度的不确定性。除了35种经典p核素外，还测定了放射性核素Nb-92、Tc-97、Tc- 98、Sm-146以及丰度比Y（Mo-92）/Y（Mo-94）、Y（Nb-92）/Y（Mo-92）、Y（Tc-97）/Y（Ru-98）、Y（Tc-98）/Y（Ru-98）和Y（Sm-146）/Y（Sm-144）的丰度不确定度。对银河系化学演化研究很重要。未发现的一般低于2的一个因素，虽然大多数核合成流主要涉及预测率较大的不确定性。对总不确定性的主要贡献来自于一组来自爆炸白色矮星内部的具有高峰密度的轨道。低密度和高密度轨道之间的区别允许得出更一般的结论，也适用于其他白色矮星爆炸的模拟。
Thermonuclear supernovae originating from the explosion of a white dwarf accreting mass from a companion star have been suggested as a site for the production of p nuclides. Such nuclei are produced during the explosion, in layers enriched with seed nuclei coming from prior strong s processing. These seeds are transformed into proton-richer isotopes mainly by photo-disintegration reactions. Several thousand trajectories from a 2D explosion model were used in a Monte Carlo approach. Temperature-dependent uncertainties were assigned individually to thousands of rates varied simultaneously in post-processing in an extended nuclear reaction network. The uncertainties in the final nuclear abundances originating from uncertainties in the astrophysical reaction rates were determined. In addition to the 35 classical p nuclides, abundance uncertainties were also determined for the radioactive nuclides Nb-92, Tc-97,Tc- 98, Sm-146, and for the abundance ratios Y(Mo-92)/Y(Mo-94), Y(Nb-92)/Y(Mo-92), Y(Tc-97)/Y(Ru-98), Y(Tc-98)/Y(Ru-98), and Y(Sm-146)/Y(Sm-144), important for Galactic Chemical Evolution studies. Uncertainties found were generally lower than a factor of 2, although most nucleosynthesis flows mainly involve predicted rates with larger uncertainties. The main contribution to the total uncertainties comes from a group of trajectories with high peak density originating from the interior of the exploding white dwarf. The distinction between low-density and high-density trajectories allows more general conclusions to be drawn, also applicable to other simulations of white dwarf explosions.