Supernova Progenitors, Stellar Remnants, and their Binary Companions

在过去的十年中，双星系统的研究再次引起了人们的关注，因为它们在广泛的天文学领域发挥着关键作用：x射线和脉冲星双星、伽马射线暴、系外行星、引力波源、超新星（SN）祖先、宇宙学，尤其是瞬态天文学。观测的进步已经改变了景观，并突出了当前建模尝试的局限性。与此同时，近十年来，二元演化模型并没有取得显著进展；反过来，这也限制了我们理解和解释与双星群相关的一些当前观测结果的能力。基于他们过去的经验，该项目的研究人员将推进二进制建模和紧凑物体形成和演化的物理复杂性。他们将开发下一代二进制种群模拟工具（PSyDLib），该工具具有自一致的物理建模的主要关键优势。该团队将利用持续增长的计算能力和MESA的公共可用性，MESA是一种通用的，强大的恒星结构和进化代码。所有的模拟代码都将公开供其他研究项目使用。该项目将利用PI与当地学校（芝加哥地区的城市和郊区）建立的联系，以前/现在与高中教师的合作，以及天文学对儿童的吸引力，以解决小学和中学STEM教育的关键需求。在所有学校，目前正在实施的下一代科学标准要求引入和使用计算思维和建模。然而，在这一领域，大多数学校教师缺乏专门知识，并表示他们需要专业发展和适当的课程材料。PI将与经验丰富的教师组成的小组合作，开发计算天文学课程材料。PI还将利用过去在天文学可视化方面的工作，并开发新的双星传质和x射线双星形成的方法。PI将在芝加哥阿德勒天文馆和埃文斯顿高中新天文馆的公众宣传演讲中广泛使用它们。PI还将包括两名女研究生，她们将接受高级计算方面的培训，从而为多样化、具有全球竞争力的STEM劳动力做出贡献。从技术上讲，该团队将开发新的模块和创新的混合软件结构，以结合(i)真实的传质序列和稳定性的物理评估，（ii）对共同包络演化的高级处理，消除了对特别参数化的需要，以及（iii）由于潮汐和传质导致的偏心、异步双星的一般情况下的自一致轨道演化。该项目的科学目标集中在研究(i)核心坍缩超新星的物理特性及其双星伴星，并与超新星调查的观测结果进行比较；（ii）银河系和麦哲伦星云中的高质量x射线双星，它们提供了大量的观测系统，其特性与最初预期的非常不同。考虑到更多的XRB样本，研究人员实际上将使用（ii）中的比较来校准他们的模型并评估(i)预测的可靠性。预期的结果不仅有助于解释当前的观测结果，而且还将为未来的多波长观测提供动力和预测。

The study of binary stellar systems has attracted renewed attention in the past decade as they are shown to play a critical role in a wide range of astronomy areas: X-ray and pulsar binaries, gamma-ray bursts, extrasolar planets, gravitational-wave sources, supernova (SN) progenitors, cosmology, and especially transient astronomy. Observational advances have transformed the landscape and have highlighted the limitations of current modeling attempts. At the same time binary evolution modeling has not advanced significantly in the past decade; in turn, this has limited our ability to understand and interpret a number of current observational results related to binary populations. Building on their past experience, the investigators in this project will advance the physical sophistication of binary modeling and compact object formation and evolution. They will develop the next-generation binary-populations simulation tool (PSyDLib) with major, key advantages for self-consistent, physical modeling. The team will take advantage of the continued increase in computational power and the public availability of MESA, a versatile, robust stellar structure and evolution code. All the simulation codes will be made publicly available for other research projects.This project will take advantage of the PI's established connections with local schools (urban and suburban in the Chicago area), prior/current work with high-school teachers, and astronomy's appeal to children to address a critical need in elementary- and middle-school level STEM education. At all school levels the Next Generation Science Standards that are currently being implemented call for the introduction and use of computational thinking and modeling. However, in this area most school teachers do not have expertise and voice their need for professional development and appropriate curriculum materials. In collaboration with small teams of experienced teachers, the PI will develop computational astronomy curriculum materials. The PI will also capitalize on past work on astronomy visualizations and develop new ones for mass transfer in binaries and X-ray binary formation. The PI will use them extensively at public outreach presentations at Chicago's Adler Planetarium and the Evanston High School new planetarium. The PI will also involve two female graduate students who will be trained in advanced computation, hence contributing to a diverse, globally competitive STEM workforce.More technically, the team will develop new modules and an innovative hybrid software structure to incorporate (i) realistic mass-transfer sequences and physical assessment of stability, (ii) advanced treatment of common-envelope evolution eliminating the need for ad-hoc parameterization, and (iii) self-consistent orbital evolution for the general case of eccentric, asynchronous binaries due to tides and mass transfer. The project's science goals focus on studies of (i) core-collapse supernovae in terms of the physical properties of both their progenitors and their binary companions and compare to observational results from supernova surveys and (ii) high-mass X-ray binaries in the Milky Way and the Magellanic Clouds, which provide a plethora of observed systems with very different properties than originally expected. Given the more substantial XRB samples, the investigators will actually use the comparisons in (ii) to calibrate their models and assess the reliability of predictions for (i). The anticipated results will not only help to explain current observations but will also provide motivation and predictions for future multi-wavelength observations.