The Realizability of the Double-Detonation Mechanism for Type Ia Supernovae

Ia型超新星双爆机制的可实现性

• 批准号: 2307442
• 负责人: Dean Townsley
• 金额: $ 25.99万
• 依托单位: University of Alabama Tuscaloosa
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-01 至 2026-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2307442&HistoricalAwards=false
• 关键词: Realizability; Double; Detonation; Mechanism; Type

Type Ia supernovae (SN) play an essential role in measuring the accelerating expansion of the Universe, produce half of the Universe’s heavy metals, and serve as testbeds for stellar hydrodynamics, nuclear physics, binary stellar evolution, and many other aspects of astrophysics. However, despite their importance and several decades of observational and theoretical investigation, the detailed nature of the stellar systems that give rise to these explosions remains uncertain. A research team at the University of Alabama Tuscaloosa will use computer-based numerical simulations to investigate one of the most promising candidate scenarios for a SN Ia explosion. This scenario, called the “double-detonation” mechanism, starts with an explosive helium detonation on the surface of a highly compact white dwarf star, which in turn yields a carbon-burning detonation in the core of that star. The research will involve the training of graduate and undergraduate students in high performance computing and the development of scientific software. Along with research products, this work will produce short videos of scientific results intended for a general audience, a portable planetarium program for small groups, and simple simulations of stellar explosions that can be run by students in upper-division astronomy courses.Obstacles remain to understanding the double-detonation mechanism and this work will help resolve them. The detailed mechanism of the first ignition in the helium shell of the star is still unclear, calling into question the robustness of this critical stage of the beginning of the explosion. In order for this scenario to be viable as a major contributor to SNe Ia, the ignition process must not just be possible under fine-tuning, but robust and almost universal. Secondly, based on recent simulations, it is clear that the detailed structure of the outer layers of the exploding star and the presence of the companion star are critical to determining whether the resulting supernova matches those observed. Using tailored simulations, the work will determine whether a realistic ignition and surface layer structure placed in a binary star system leads to realistic supernovae. This project is jointly funded by the Division of Astronomical Sciences and the Established Program to Stimulate Competitive Research (EPSCoR).This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

Ia 型超新星 (SN) 在测量宇宙加速膨胀方面发挥着重要作用，产生了宇宙一半的重金属，并充当恒星流体动力学、核物理、双星演化和天体物理学许多其他方面的试验台。尽管它们很重要，并且经过了数十年的观测和理论研究，但引起这些爆炸的恒星系统的详细性质仍然不确定，阿拉巴马州塔斯卡卢萨大学的一个研究小组将使用基于计算机的数值模拟。调查最有希望的 SN Ia 爆炸候选者之一，这种被称为“双爆炸”机制的情况是从高度致密的白矮星表面的氦爆炸开始，进而产生碳-该研究将涉及对研究生和本科生进行高性能计算和科学软件开发的培训，以及研究产品，并将制作用于一般用途的科学成果短片。观众，一个针对小组的便携式天文馆程序，以及可由高级天文学课程的学生运行的简单的恒星爆炸模拟。理解双爆炸机制仍然存在障碍，这项工作将有助于解决这些障碍的详细机制。恒星氦壳中的第一次点火仍不清楚，这使人对爆炸开始的这一关键阶段的稳健性产生疑问。其次，根据最近的模拟，很明显，爆炸恒星外层的详细结构和伴星的存在对于点火过程至关重要。确定由此产生的超新星是否与观测到的相匹配，这项工作将确定双星系统中的真实点火和表面层结构是否会产生真实的超新星。该项目由天文科学部和已建立的机构共同资助。程序刺激竞争性研究 (EPSCoR)。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力优点和更广泛的影响审查标准进行评估，被认为值得支持。