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arXiv 1012.4917astro-ph.SRnucl-exnucl-th
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核心坍缩超新星中的爆炸核合成

Explosive nucleosynthesis in core-collapse supernovae

A. Arcones

摘要:

通过快速中子俘获(r-过程)产生比铁重的一半元素的具体机制和天体物理学位置仍有待发现。为了重现太阳系和古老晕星的丰度,至少需要两种成分:重r-过程核(A>130)和对应于较轻重核(A<130)的弱r-过程。在这项工作中,我们提出了核合成研究的基础上的轨道流体动力学模拟核心坍缩超新星和随后的中微子驱动的风。我们表明,弱的r-过程元素可以产生中微子驱动的风,我们把它们的丰度从新生的中子星的中微子发射。根据最新的流体动力学模拟,重r过程元素不能在中微子驱动的风中合成。然而,通过人为地增加风熵,可以制造高达A=195的元素。用这种方法,人们可以模拟出发生r过程的喷出物的一般行为。我们用它来研究核物理输入(核质量,中子俘获截面,β-延迟中子发射)和长期动力学演化对最终丰度的影响。

英文摘要:

The specific mechanism and astrophysical site for the production of half of the elements heavier than iron via rapid neutron capture (r-process) remains to be found. In order to reproduce the abundances of the solar system and of the old halo stars, at least two components are required: the heavy r-process nuclei (A>130) and the weak r-process which correspond to the lighter heavy nuclei (A<130). In this work, we present nucleosynthesis studies based on trajectories of hydrodynamical simulations for core-collapse supernovae and their subsequent neutrino-driven winds. We show that the weak r-process elements can be produced in neutrino-driven winds and we relate their abundances to the neutrino emission from the nascent neutron star. Based on the latest hydrodynamical simulations, heavy r-process elements cannot be synthesized in the neutrino-driven winds. However, by artificially increasing the wind entropy, elements up to A=195 can be made. In this way one can mimic the general behavior of an ejecta where the r-process occurs. We use this to study the impact of the nuclear physics input (nuclear masses, neutron capture cross sections, and beta-delayed neutron emission) and of the long-time dynamical evolution on the final abundances.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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