Monte Carlo NLTE Radiation Transfer in Circumstellar Disks

星周盘中的蒙特卡罗 NLTE 辐射传输

• 批准号: 0307686
• 负责人: Jon Bjorkman
• 金额: $ 39.07万
• 依托单位: University of Toledo
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-08-15 至 2008-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0307686&HistoricalAwards=false
• 关键词: Monte; Carlo; NLTE; Radiation; Transfer

AST 0307686PI BjorkmanNew high-resolution observations of circumstellar environments are beginning to provide a wealth of detail about the nature of the physical processes occurring in stellar envelopes. These observations dramatically demonstrate that both axisymmetric and clumpy structures are ubiquitous, occurring in a diverse range of astrophysical systems, such as young stellar objects, outflows from highly evolved stars, and the explosive eruptions seen, for example, in novae, and supernovae. However to fulfill the promise of using these data to uncover the underlying physical mechanisms governing these phenomena, adequate theoretical techniques must be developed for investigating the transfer of radiation through matter with complex geometries. In this research 2- and 3-dimensional Monte Carlo simulations of the radiation transfer in these environments will be carried out. The geometries investigated primarily are the axisymmetric, disk-like structures produced around young stellar objects, highly evolved objects, and rotating stellar winds. Additional studies will investigate asymmetries in these environments, such as the clumpy winds of hot stars and spiral density waves in circumstellar disks.Broader Impact. This work supports both a post-doctoral researcher and a graduate student, and hence directly contributes to the training of future researchers. In addition to graduate students, the principle investigator regularly works with undergraduates and exchange students leading to on-going collaborations with researchers in Brazil. To help enrich the local community, public lectures on this research are given, as well as teacher training workshops to K-12 teachers to help train the teachers in the practical use of hands-on activities for their classroom. Finally, this research is developing new parallel computing algorithms, which ultimately will benefit other researchers interested in multi-dimensional radiation transfer.

AST 0307686 PI Bjorkman对星周环境的新的高分辨率观测开始提供关于恒星包层中发生的物理过程的性质的大量细节。这些观测结果戏剧性地表明，轴对称和星团结构都是普遍存在的，发生在不同的天体物理系统中，例如年轻的恒星物体，高度演化的恒星的外流，以及在新星和超新星中看到的爆炸性爆发。然而，为了实现使用这些数据来揭示这些现象的潜在物理机制的承诺，必须开发足够的理论技术来研究辐射通过具有复杂几何形状的物质的传输。 在这项研究中，2-和3-维蒙特卡罗模拟在这些环境中的辐射传输将进行。研究的几何形状主要是围绕年轻恒星物体、高度演化的物体和旋转的恒星风产生的轴对称盘状结构。进一步的研究将调查这些环境中的不对称性，例如热恒星的星云风和星周盘中的螺旋密度波。这项工作支持博士后研究人员和研究生，因此直接有助于培养未来的研究人员。 除了研究生之外，主要研究人员还定期与本科生和交换生合作，从而与巴西的研究人员进行持续合作。为了帮助丰富当地社区，就这项研究进行了公开讲座，并为K-12教师举办了教师培训研讨会，以帮助培训教师在课堂上实际使用实践活动。 最后，这项研究正在开发新的并行计算算法，这最终将有利于其他研究人员感兴趣的多维辐射传输。