Composition of the Innermost Core-Collapse Supernova Ejecta
Composition of the Innermost Core-Collapse Supernova Ejecta
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最内层核心塌缩超新星喷射物的成分
DOI：
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发表时间：
2004
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通讯作者：
K. Nomoto
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作者：
C. Frohlich;P. Hauser;M. Liebendoerfer;G. Martínez;F. Thielemann;E. Bravo;N. Zinner;W. Hix;K. Langanke;A. Mezzacappa;K. Nomoto
在目前已知的一维输入物理和计算机模拟下，对核心坍缩超新星的自洽处理尚未导致成功的爆炸，而二维模型显示出一些希望。因此，有强烈的迹象表明，延迟中微子机制的工作结合多维对流处理不稳定层（可能与旋转，磁场和/或仍然存在的中微子不透明度的不确定性的援助）。另一方面，有必要提供正确的核合成丰度的星系演化和低金属丰度恒星的观测领域的进展。最里面的喷出物直接受到爆炸机制的影响，即，最强烈的是，Fe族核的产额，对于Fe族核，诱导活塞或热弹处理将不能提供正确的产额，因为没有包括中微子相互作用的影响。我们应用参数化的变化，中微子散射截面，以模仿在一个维度上的中微子光度的不确定性所造成的原中子星星对流的可能增加。或者，参数化的变化被施加到中微子吸收截面的核子在“增益区”，以模仿中微子能量沉积的增加，使对流营业额。我们发现，这两种措施导致类似的结果，导致爆炸和一个叶> 0.5的最里面的喷射层，由于一个短的弱相互作用的时间尺度和一个可以忽略不计的电子简并的综合效应，揭示了质子-中子质量差。我们包括所有的弱相互作用（电子和正电子捕获，β衰变，中微子和反中微子捕获的核，中微子和反中微子捕获的核子）和目前的第一个核合成的结果，这些最内层的喷射层，讨论他们如何改善预测的Fe族核。质子丰富的环境导致45 Sc，49 Ti和64 Zn的丰度增强，这是化学演化研究和低金属丰度恒星观测所需的，以及在质量范围高达A = 80的核的可观生产。
With currently known input physics and computer simulations in one dimension, a self-consistent treatment of core-collapse supernovae does not yet lead to successful explosions, while two-dimensional models show some promise. Thus, there are strong indications that the delayed neutrino mechanism works combined with a multidimensional convection treatment for unstable layers (possibly with the aid of rotation, magnetic fields and/or still existent uncertainties in neutrino opacities). On the other hand, there is a need to provide correct nucleosynthesis abundances for the progressing field of galactic evolution and observations of low-metallicity stars. The innermost ejecta is directly affected by the explosion mechanism, i.e., most strongly, the yields of Fe group nuclei for which an induced piston or thermal bomb treatment will not provide the correct yields because the effect of neutrino interactions is not included. We apply parameterized variations to the neutrino-scattering cross sections in order to mimic in one dimension the possible increase of neutrino luminosities caused by uncertainties in proto-neutron star convection. Alternatively, parameterized variations are applied to the neutrino absorption cross sections on nucleons in the "gain region" to mimic the increase in neutrino energy deposition enabled by convective turnover. We find that both measures lead to similar results, causing explosions and a Ye > 0.5 in the innermost ejected layers, due to the combined effect of a short weak-interaction timescale and a negligible electron degeneracy, unveiling the proton-neutron mass difference. We include all weak interactions (electron and positron capture, β-decay, neutrino and antineutrino capture on nuclei, and neutrino and antineutrino capture on nucleons) and present first nucleosynthesis results for these innermost ejected layers to discuss how they improve predictions for Fe group nuclei. The proton-rich environment results in enhanced abundances of 45Sc, 49Ti, and 64Zn as required by chemical evolution studies and observations of low-metallicity stars, as well as appreciable production of nuclei in the mass range up to A = 80.