Elliptical Polarization as a Probe of the Magnetic Fields in AGNs

椭圆偏振作为活动星系核磁场的探针

• 批准号: 0307629
• 负责人: Hugh Aller
• 金额: $ 36.52万
• 依托单位: Regents of the University of Michigan - Ann Arbor
• 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: 2003-07-15 至 2007-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0307629&HistoricalAwards=false
• 关键词: Elliptical; Polarization; Probe; Magnetic; Fields

AST-0307629AllerThe link between the black hole and accretion disk at the heart of active galactic nuclei (AGN), and the radio jets commonly observed in these sources and apparently emanating from the central engine, remains an unanswered question. Past work has successfully treated the radio jets as hydrodynamical flows with passive magnetic fields, even though the magnetic energy must be high. This research will explore the connection between these regimes, using multi-frequency radio polarimetry observations to measure directly the magnetic field strength and orientation. Both single dish and interferometric observations of linear and circular polarization at multiple frequencies, over timescales of weeks to decades, are necessary and will be obtained, and interpreted using associated modeling. A valuable by-product will be information on particle composition and particle energy distribution, fundamental jet properties which remain unknown. The database of unique measurements will be made readily available, and the research will help maintain one of the few radio telescopes available in the US for hands-on student training.***

AST-0307629Aller 活动星系核 (AGN) 中心的黑洞和吸积盘，以及在这些源中常见的、显然是从中央引擎发出的射电喷流之间的联系，仍然是一个悬而未决的问题。 过去的工作已成功地将无线电射流视为具有被动磁场的流体动力流，尽管磁能必须很高。 这项研究将探索这些状态之间的联系，利用多频射电极化观测直接测量磁场强度和方向。 在数周至数十年的时间尺度内，对多个频率下的线偏振和圆偏振进行单碟和干涉观测都是必要的，并且将使用相关模型来获得和解释。 一个有价值的副产品将是关于颗粒成分和颗粒能量分布的信息，以及仍然未知的基本射流特性。 独特测量的数据库将随时可用，并且该研究将有助于维护美国为数不多的射电望远镜之一，用于学生实践培训。***