Core-Collapse Supernovae Through Cosmic Time

穿越宇宙时间的核心塌陷超新星

• 批准号: 1440045
• 负责人: Eric Lentz
• 金额: $ 2.27万
• 依托单位: University of Tennessee Knoxville
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-01 至 2017-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1440045&HistoricalAwards=false
• 关键词: Core; Collapse; Supernovae; Through; Cosmic

When massive stars (those with at least 8 times the Sun's mass) reach the end of their existence they can explode releasing large quantities of heavy elements that enrich the next generation of stars. Modeling these core-collapse supernovae and their ejecta requires complex and well resolved three-dimensional numerical simulations running on large computers. The abundances of heavy elements (known as 'metals' to astronomers) has increased from none in the very first stars formed after the Big Bang to the Solar-like composition found in recently formed stars in the nearby universe. Supernovae are dependent on the pre-explosion structure of the star, which is dependent on both the stellar mass and the amount of 'metals' in the star. To cover the variation through cosmic time in the stars that explode as supernovae we will compute three well-resolved 3D supernova simulations for low, medium, and high mass exploding stars at each of three 'metallicities' representing the build-up of heavy elements from the primordial zero metallicity to solar metallicity. From these simulations the investigators will extract the properties of the explosions and their ejecta to get a better understanding of the nature of the supernova mechanism and its contributions to the evolution of galaxies through cosmic time.The investigators will use their multi-physics Chimera code, which includes neutrino radiation hydrodynamics with modern neutrino-matter interactions, general relativistic corrections to multi-pole self-gravity, a dense matter nuclear equation of state, and built-in nuclear networks to compute evolving abundances in the non-equilibrium layers outside the iron-core and in the ejecta. The three simulations of 1-degree resolution will be computed at each metallicity from low (about 10 solar mass), medium (15 solar mass), and high (about 25 solar mass) progenitors found to explode in similar 2D (axisymmetric) simulations. Simulations will be computed at zero, solar, and low metallicities and both direct and post-processed nucleosynthesis will be computed for the ejecta. Additional analyses will produce gravitational wave and neutrino signals that directly probe the central supernova engine.

当大质量恒星（至少是太阳质量的8倍）到达生命的尽头时，它们会爆炸，释放出大量的重元素，丰富下一代恒星。对这些核心坍缩的超新星及其喷出物进行建模需要在大型计算机上运行复杂且分辨率良好的三维数值模拟。重元素（天文学家称之为“金属”）的丰度从大爆炸后形成的第一颗恒星中的零增加到最近在附近宇宙中形成的恒星中发现的类似太阳的成分。超新星取决于星星爆炸前的结构，这取决于恒星质量和星星中“金属”的数量。为了涵盖宇宙时间的变化，在恒星爆炸为超新星，我们将计算三个分辨率良好的3D超新星模拟低，中，高质量的爆炸恒星在每三个“金属丰度”代表积累的重元素从原始的零金属丰度太阳金属丰度。从这些模拟中，研究人员将提取爆炸及其喷出物的性质，以更好地了解超新星机制的本质及其对宇宙时间内星系演化的贡献。研究人员将使用他们的多物理Chimera代码，其中包括中微子辐射流体动力学与现代中微子-物质相互作用，对多极自引力的广义相对论修正，一个稠密物质核状态方程，和内置的核网络，以计算不断变化的丰度在非平衡层以外的铁核心和喷出物。在类似的2D（轴对称）模拟中，将从低（约10个太阳质量）、中（15个太阳质量）和高（约25个太阳质量）的祖先中计算出每种金属丰度的三个1度分辨率的模拟。模拟将计算在零，太阳，和低金属丰度和直接和后处理的核合成将计算喷出物。额外的分析将产生引力波和中微子信号，直接探测中央超新星发动机。