Collaborative Research: Asymmetry is Destiny: Structure and Fate of Wolf-Rayet Binary Systems

超新星是已知能量最大的爆炸。能量最高的超新星（SNe）被认为是由快速旋转的星星直接坍缩成黑洞形成的。产生这些SNe的恒星系统的类型还不太清楚。被称为沃尔夫-拉叶星（WR）的非常热的大质量恒星能够产生在这种SNe爆炸中观察到的特征。然而，在星星系统中WR星在产生超新星中的作用还没有详细的观测研究。研究人员将使用大型望远镜来展示SNe爆炸产生的光是如何偏振的，这将有助于确定爆炸是如何发生的。然后，他们将使用计算机模型来更好地理解和解释从超新星中流出的物质。他们将为有色人种的中学女生组织一个夏令营，并在整个学年中提供指导。然后，他们将评估在USNA建立这样一个项目的可行性。本计画利用分光偏振法，观测确定WR双星的风形态。偏振光谱法探测偏振发射线的散射历史，揭示它们在系统内的形成和散射位置。V444 Cyg系统是一个典型的WR+O食双星，现有的偏振观测表明，由于两颗恒星的风碰撞，存在激波锥结构。该研究将量化类似系统中的这种行为，并确定WR+O显示中风的形态特征范围。蒙特卡洛建模将允许团队解释结果，预测相互作用的双星的极化特征，并将结果与当前的WR风和双星演化理论进行比较。他们建议继续一个成功的试点项目，使用南非大望远镜上的RRS仪器，为~15 WR双星系统构建良好采样的偏振相位曲线。该奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的知识价值和更广泛的影响审查标准进行评估的支持。

Supernovae are the most energetic explosions known. The very most energetic supernovae (SNe) are thought to form from the direct collapse of a rapidly rotating star into a black hole. The types of stellar systems which produce these SNe are not well understood. The very hot, massive stars known as Wolf-Rayet (WR) stars are capable of producing features observed in such SNe explosions. However, the role of WR stars in binary star systems in producing supernovae has not been observationally studied in detail. The investigators will use large telescopes to show how the light from such SNe explosions is polarized; this will help determine how the explosion occurred. They will then use computer models to better understand and interpret material flowing out from the supernovae. They will organize a summer camp for middle-school girls of color, following up with mentoring throughout the school year. They will then assess the feasibility of establishing such a program at USNA. This project uses the method of spectropolarimetry to observationally determine the morphology of the winds in WR binaries. Spectropolarimetry probes the scattering history of polarized emission lines, revealing their formation and scattering locations within the system. Existing polarimetric observations of the V444 Cyg system, a prototypical WR+O eclipsing binary, suggest that a shock-cone structure exists due to the collision of the two stars' winds. The study will quantify this behavior in similar systems and determine the range of morphological characteristics winds in WR+O display. Monte Carlo modeling will allow the team to interpret the results, predict polarimetric signatures from interacting binary stars, and compare the results to current theories of WR winds and binary evolutions. They propose to continue a successful pilot project using the RRS instrument on the South African Large Telescope to construct well-sampled polarization phase curves for ~15 WR binary systems.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.