Collaborative Research: RUI: Tracing the Spectropolarimetric History of Circumstellar Structures from High-Mass Stars through Supernovae

合作研究：RUI：追踪从大质量恒星到超新星的绕星结构的光谱偏振历史

• 批准号: 0807664
• 负责人: Richard Ignace
• 金额: $ 61.7万
• 依托单位: East Tennessee State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-08-01 至 2015-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0807664&HistoricalAwards=false
• 关键词: Collaborative; Research; RUI; Tracing; Spectropolarimetric

Though their field was once thought to be reasonably well-understood, astronomers in the massive-star community are now faced with a number of new and fundamental questions about the non-spherical character of stellar mass loss. The nature and extent of wind clumping remains an unsolved problem; recent studies suggest that due to this clumpiness, O star mass-loss rates should be revised downward by an order of magnitude or more. In addition, a growing body of evidence shows that magnetic fields can influence the geometry of mass loss in hot star winds in unanticipated ways. The effects of stellar rotation on the structure and formation of disks around some main sequence and post-main sequence massive stars are still not fully understood. Meanwhile, detailed observations of supernovae reveal that many more core-collapse objects interact extensively with aspherical circumstellar environments than previously realized, and signatures of this interaction may be mined for clues to the mass-loss histories of massive supernova progenitors.This project is a comprehensive study of clumpy and aspherical structures in the circumstellar media of massive stars and supernovae. Motivated by access to high-resolution spectropolarimetric data and using an established Monte Carlo radiative transfer code, Drs. Ignace and Hoffman, and their team, will construct simulations of variable line and continuum polarization in the stochastically clumped winds of Wolf Rayet, luminous blue variable, and O stars; in the disks and rotating magnetospheres of other active stars; and in core-collapse supernovae interacting with their immediate environments. They will also develop algorithms that will allow the modeling code to simulate line polarization arising from the Zeeman and Hanle effects from the circumstellar fields of magnetized stars. The investigators have broad experience in both radiation transport techniques and interpreting spectropolarimetric observations of hot star winds and interacting supernovae. By confronting detailed 3D models of these systems with multiwavelength and polarimetric data, the goal is a better understanding of how the mass-loss history of main-sequence and evolved massive stars can be extracted from their observation and those of core collapse supernovae.The project includes a unique outreach program, Promoting Careers in Science, through which Drs. Ignace and Hoffman will each implement innovative strategies for improving science education and literacy in their respective communities. Dr. Ignace will reach out to school counselors to enhance science education among Appalachian middle- and high-school students. Dr. Hoffman will partner with the University of Denver's Women's College to create new entry points into the scientific career 'pipeline' for non-traditional female undergraduate students. In addition, Dr. Ignace will continue supervising undergraduate research projects both through East Tennessee State University and through involvement in an REU site program. The bulk of the 5-year funding will go to support the training and professional development of a postdoctoral researcher at East Tennessee State University and a graduate student at the University of Denver who will be trained in the theoretical modeling of radiation transfer.

尽管他们的领域曾经被认为是合理地理解的，但大型明星社区中的天文学家现在面临着许多关于恒星群众损失的非球面特征的新的和根本的问题。风块的性质和程度仍然是一个未解决的问题。最近的研究表明，由于这种块状，应通过数量级或更多的数量级向下修改o恒星质量损失率。此外，越来越多的证据表明，磁场可以以意外的方式影响热星风中质量损失的几何形状。恒星旋转对某些主序列和后脑后序列围绕磁盘结构和形成的影响仍未完全了解。同时，对超新星的详细观察结果表明，比以前实现的许多核心爆发物体与非球形环境环境广泛相互作用，并且这种相互作用的签名可能是为大规模超级新星祖细胞的大规模历史而挖掘的签名。这些项目是一项全面的群集和地下的群众群体，是一项全面的群众群体和地下的媒体。通过访问高分辨率光谱数据的动机，并使用已建立的蒙特卡洛辐射转移代码DRS进行动机。 Ignace和Hoffman及其团队将在随机的狼雷特，发光蓝色变量和O星的随机聚集中构建可变线和连续极化的模拟；在其他活性恒星的磁盘和旋转磁层中；在核心溢出中，超新星与它们的直接环境相互作用。他们还将开发算法，这些算法将允许建模代码模拟由磁化恒星室外场的Zeeman和Hanle效应产生的线极化。研究人员在辐射传输技术和解释热星风和相互作用的超新星的光谱观测方面都有广泛的经验。通过与这些系统的详细3D模型与多波长和极化数据面对面，目标是更好地理解主要序列和进化的巨大恒星的大规模损害历史，并从其观察中提取了核心崩溃超新星的群众。 Ignace和Hoffman将各自实施创新策略，以改善各自社区的科学教育和识字率。 Ignace博士将与学校辅导员联系，以增强阿巴拉契亚中学和高中生的科学教育。霍夫曼博士将与丹佛大学的女大学合作，为非传统女性本科生的科学职业“管道”创建新的入学点。此外，Ignace博士将继续监督通过东田纳西州立大学以及参与REU站点计划的本科研究项目。 5年的大部分资金将用于支持东田纳西州立大学一名博士后研究员的培训和专业发展，以及丹佛大学的研究生，他们将接受有关辐射转移理论建模的培训。