EAPSI: Detailed Three-Dimension Simulations of an Unexplored Progenitor System for Type Ia Supernovae

Ia型超新星是白色矮星的热核爆炸。它们是伟大的宇宙探测器，因为它们的亮度几乎总是相同的，并且可以根据经验进行标准化。这些物体在1999年被用来发现暗能量，这一成就在2011年获得诺贝尔奖。然而，爆炸的恒星的性质是什么？祖先系统仍然是个谜这颗白色矮星的质量是由于它的伴星星星吸积物质而增加的。虽然Ia型超新星已经被研究了30多年，但这些爆炸的祖先系统仍然存在争议。该项目旨在研究一个提议的祖先系统，该系统在很大程度上尚未被探索。在与京都大学动力学爆炸模型专家Keiichi Maeda的合作中，研究人员将通过两颗质量不同的白色矮星合并来创建Ia型超新星的计算机模拟。这个模拟将探索质量较小的白色矮星被潮汐破坏并吸积到质量较大的白色矮星上的情况。该模型有望解决以往模型与观测结果之间的一些差异。更好地理解祖先系统将提高其作为宇宙性质探测器的有用性。本项目将创建一个流体动力学模拟的Ia型超新星从潮汐中断双degenate合并。这种模拟将用于测试这种类型的爆炸的几个属性。它将探索由于旋转而可能发生的爆炸质量的范围。这将使这个模型既能拟合阿格拉塞卡质量，也能拟合超级钱德拉爆炸。 这种爆炸类型不应该作为超软X射线源容易观察到，并且应该是近似球形的爆炸。 这两种情况都将使它与当前的观测限制兼容。该模型可以测试从这种类型的爆炸预测的丰度，并测试在低爆炸速度下碳的存在。 东亚和太平洋夏季研究所计划下的这个奖项支持美国研究生的夏季研究，由NSF和日本科学促进会共同资助。

Type Ia supernovae are thermonuclear explosions of white dwarf stars. They are great cosmic probes because their brightness is almost always the same and can be standardized empirically. These objects were used to discover the Dark Energy in 1999, an accomplishment recognized with the Nobel Prize in 2011. However, the nature of the stars that blow up?the progenitor system?remains a bit of a mystery. The mass of the white dwarf is increased by accreting material from its companion star. While Type Ia supernovae have been studied for over 30 years the progenitor system for these explosions is still disputed. This project seeks to study one proposed progenitor system that has remained largely unexplored. In collaboration with Keiichi Maeda, an expert in dynamical explosion models, at Kyoto University the researcher will create a computer simulation of a Type Ia supernova from the merger of two white dwarfs of differing masses. This simulation will explore the case where the less massive white dwarf is tidally disrupted and accretes onto the more massive white dwarf. This model is expected to resolve some discrepancies between previous models and observations. A better understanding of the progenitor system will improve its usefulness to as probes of the nature of Universe.This project will create a hydrodynamic simulation of a Type Ia supernova from a tidally disrupted double degnerate merger. This simulation will be used to test several properties of this type of explosion. It will explore the range of possible explosion masses due to spin up. This would allow this model to fit both Chandrasekhar mass as well as superchandra explosions. This explosion type should not be easily observable as a supersoft X-ray source, and should be a nearly spherical explosion. Both of these will make it compatible with current observational constraints. This model can test the abundances predicted from this type of explosion and test for the presence of carbon at low explosion velocities. This award under the East Asia and Pacific Summer Institutes program supports summer research by a U.S. graduate student and is jointly funded by NSF and the Japan Society for the Promotion of Science.