Collaborative Research: Observational testing of interstellar grain alignment theory

合作研究：星际颗粒排列理论的观测测试

• 批准号: 1109295
• 负责人: Alexandre Lazarian
• 金额: $ 14.53万
• 依托单位: University of Wisconsin-Madison
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-10-01 至 2016-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1109295&HistoricalAwards=false
• 关键词: Collaborative; Research; Observational; testing; interstellar

The collaborative research lead by Dr. Andersson (Universities Space Research Association), Dr. Jones (University of Minnesota), and Dr. Lazarian (University of Wisconsin, Madison) advances our ability to trace magnetic fields in the interstellar medium and molecular clouds through new multi-wavelength observations and theoretical modeling. It leads to a better understanding of the foregrounds to the cosmic microwave background (CMB) polarization through targeted observations of interstellar grain alignment and modeling based on the leading theoretical paradigm. The combined new quantitative effort addresses interstellar grain alignment mechanisms. A quantitative theory based on radiative alignment torques provides specific, testable predictions of the grain alignment as functions of the environment and grain characteristics. Observations, employing optical and near-infrared (NIR) polarimetry, directly probe the theoretical predictions of the variations of grain alignment efficiencies from the molecular cloud surfaces to the depths where (sub-)mm wave polarized emission is observed. Extensive modeling of the grain alignment, simulating the polarization arising from aligned grains, supports interpretations of the observations. A quantitative understanding of the alignment mechanism is important to understand the structure and strength of the magnetic field (through the geometry of the polarization vectors and the Chandrasekhar-Fermi method, respectively). The impact on related research ranges from models of star formation (through a reliable magnetic field tracing) to the physics of Early Universe (through a reliable separation of polarized dust foreground from the CMB polarized radiation) as well as a better understandinging micro-physics of interstellar dust grains. This project trains young researchers and graduate students in the acquisition, analysis and interpretation of the optical and NIR observations, and on computational models necessary for the study of astrophysical magnetic fields and the nature of interstellar polarization.

安德森（Andersson）博士（大学太空研究协会），琼斯（Jones of Minnesota大学）和Lazarian博士（威斯康星大学麦迪逊大学）的合作研究领导，通过新的多波长观测值和理论模型，通过新的多波长观测和理论模型来提高我们在星际媒介和分子云中追踪磁场的能力。它通过基于领先的理论范式的星际晶粒对准和建模，可以更好地理解前景到宇宙微波背景（CMB）极化。合并的新定量努力解决了星际谷物对准机制。基于辐射比对扭矩的定量理论提供了针对环境和谷物特征功能的晶粒比对的特定测试预测。使用光学和近红外（NIR）极化法直接探测晶粒对准效率从分子云表面到深度（亚MM波偏光发射的深度）的变化的理论预测。对晶粒比对的广泛建模，模拟由对齐的晶粒产生的极化，支持对观测值的解释。对比对机理的定量理解对于理解磁场的结构和强度很重要（分别通过极化向量和Chandrasekhar-Fermi方法的几何形状）。对相关研究的影响范围从恒星形成的模型（通过可靠的磁场追踪）到早期宇宙的物理（通过将极化尘埃前景与CMB极化辐射的可靠分离）以及更好地理解星体尘埃谷物的微物理学。该项目培训了年轻的研究人员和研究生，以对光学和NIR观察的获取，分析和解释，以及研究天体物理磁场和星际极化的性质所必需的计算模型。