Exploring the Nucleosynthesis of Core Collapse Supernovae in Multidimensions

超新星的核心坍缩除了是最具能量的天体物理事件之一之外，还是生命所必需的重元素的最多产的工厂。因此，它们在化学元素的起源和进化中扮演着关键角色，而化学元素是数学物理科学理事会“宇宙起源”主题的核心研究课题。超新星也一直并将继续成为美国国家科学基金会资助的天文、核物理和粒子物理实验和天文台的极大兴趣对象，从射电和光学望远镜到核加速器、中微子和引力波探测器。近年来，核心坍缩超新星的理论研究取得了很大进展，但仍存在一些令人信服的问题。在这个建议中，我们提出了一个计划，以提高我们对核合成的理解，核合成是在核心坍缩超新星爆炸时产生的。这项提议建立在我们目前的努力基础上，并补充了美国能源部资助的橡树岭国家实验室对核心坍缩超新星机制的研究。虽然核心坍缩超新星的理论研究在过去十年中取得了很大进展，但基本问题仍然存在，包括“中微子再加热机制，当在多维空间中精确计算时，能否成功地产生超新星爆炸？”“回答这些问题的关键是将计算模型与观测结果进行比较的能力。由于对超新星的许多重要观测都强调元素组成，因此需要对这些多维核坍缩超新星模拟的核合成进行精确计算。特别是，我们需要了解以自洽的多维方式计算的现实核合成与当前参数化的一维模型有何不同。因此，我们建议在我们世界领先的中微子辐射流体动力学能力的基础上，研究这些模型的核合成。我们的最终目标是自洽核合成，在中微子辐射流体动力学模型中原位计算，但我们也将讨论中间步骤，这将给我们一些更直接的核合成信息。“我们是星星的东西”，构成我们身体和我们的世界的化学元素起源于星星，这种认识已经深入到公众的意识中，甚至涉及到流行文化和哲学。因此，对宇宙起源的研究是具有广泛社会影响和兴趣的科学。为了回应公众的好奇心，近年来，Hix和Mezzacappa已经就这个话题做了几次公开讲座，并希望继续这样做，作为这项提议的一部分。这一建议将进一步促进核物理学和天体物理学之间的跨学科合作。这一建议也将在多个方面促进教育和专业发展。该提案将资助一名研究生参与ORNL的超新星研究工作，为学生提供进入世界一流科学环境的教育机会。我们也期待暑期本科生参与这项研究，就像我们过去一样，通过田纳西州资助的科学联盟。最后，这个提议将允许希克斯发展他的独立研究议程，进一步发展他作为一名科学家。

In addition to being among the most energetic of astrophysical events, core collapsesupernovae are the most productive factories of the heavy elements which are necessary forlife. As a result, they are critical players in the origin and evolution of the chemicalelements, a subject of study central to the Directorate of Mathematical \& PhysicalSciences' Origins of the Universe theme. Supernovae have also been, and continue to be,objects of great interest to a wide range of NSF-funded astronomical, nuclear and particlephysics experiments and observatories, from radio and optical telescopes to nuclearaccelerators and neutrino and gravity wave detectors. The theoretical study of corecollapse supernovae has progressed greatly in recent years, however compelling questionsremain.In this proposal, we advance a plan to improve our understanding ofthe nucleosynthesis which results when a core collapse supernovae explodes. This proposalbuilds on our current efforts and is complimentary to DoE funded research into the corecollapse supernova mechanism at Oak Ridge National Laboratory. While the theoreticalstudy of core collapse supernovae has progressed greatly in the past decade, fundamentalquestions remain, including ''Can the neutrino reheating mechanism, when calculatedaccurately in multidimensions, successfully produce supernova explosions?'' Key toanswering these questions is the ability to compare the computed models with observations.Since many of the important observations of supernovae highlight the elementalcomposition, accurate calculation of the nucleosynthesis of these multi-dimensional corecollapse supernova simulations is needed. In particular, we need to see how realisticnucleosynthesis, calculated in a self-consistent multi-dimensional fashion, differs fromcurrent parameterized one dimensional models. We therefore propose to build on ourworld-leading neutrino radiation hydrodynamic capability and investigate thenucleosynthesis of these models. Our ultimate goal is self consistent nucleosynthesis,calculated in situ within the neutrino radiation hydrodynamic models, but we will alsodiscuss interim steps that will give us some nucleosynthesis information more immediately.The realization that "we are star stuff", that the chemical elements that compose ourbodies and our world originate in stars, has penetrated deep into the public awareness,reaching as far as pop culture and philosophy. Thus, the study of Cosmic Origins isscience with broad societal impact and interest. In response to this public curiosity,Hix and Mezzacappa have given several public lectures on this topic in recent years andexpect to continue to do so as part of this proposed effort. This proposal would furtherthe interdisciplinary collaboration between nuclear physics and astrophysics. Thisproposal would also further educational and professional development on several fronts.This proposal would fund the involvement of a graduate student in supernova researchefforts at ORNL, providing educational access to a world class scientific environment. Wealso anticipate the involvement in this research of summer undergraduate students, as wehave in the past, through the Science Alliance funded by the state of Tennessee. Finallythis proposal would allow Hix to develop his independent research agenda, furthering hisdevelopment as a scientist.