Milliarcsecond Polarization Studies of Compact ExtragalacticRadio Sources

紧凑型河外射电源的毫弧秒偏振研究

• 批准号: 8901743
• 负责人: John F. Wardle
• 金额: $ 17.52万
• 依托单位: Brandeis University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-07-01 至 1993-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8901743&HistoricalAwards=false
• 关键词: Milliarcsecond; Polarization; Studies; Compact; ExtragalacticRadio

The distributions of the linear polarization of radio wavelength emission from compact radio sources will be studied at milliarcsecond resolution using the technique of the Very Long Baseline Interferometry (VLBI). These radio sources are associated with the nuclei of quasars and active galaxies, where enormous amounts of energy are emitted on very short timescales, probably due to the infall of material onto a supermassive black hole. The energy manifests itself as radiation on all parts of the electromagnetic spectrum. At radio wavelengths we see compact radio-emitting `cores' and `jet-like' features, that vary rapidly in both total intensity and polarization. In many sources, bright knots of emission appear to be moving down the jets at several times the speed of light. The goals of the observations are: (1), to map the topology of the magnetic field structures and to study their evoulution; (2), to obtain kinematic and geometric information to constrin models of superluminal sources; (3), to help understand the differences between differnt classes of compact radio sources; (4), to probe the plasma surrounding the rdio sources in the innermost regions of quasars and active galactic nuclei; and (5), to study the relationship between the milliarcsecond radio structure and the large scale (much greater than 1 arcsecond) jets and lobes found in extended radio sources.

利用甚长基线干涉测量（VLBI）技术，在毫弧秒分辨率下研究了紧密型射电源发射的射电波长线偏振分布。这些射电源与类星体和活动星系的核有关，在那里，大量的能量在很短的时间尺度上发射出来，可能是由于物质落入超大质量黑洞。能量在电磁波谱的所有部分表现为辐射。在无线电波长上，我们看到紧凑的无线电发射“核心”和“射流”特征，它们在总强度和极化上变化迅速。在许多来源中，明亮的发射结似乎以几倍于光速的速度沿着喷流移动。观测的目的是：(1)绘制磁场结构的拓扑图并研究其演化；(2)获取超光速光源约束模型的运动学和几何信息；(3)，帮助了解不同类别的紧凑型射电源之间的差异；(4)探测类星体和活动星系核最内层射电源周围的等离子体；(5)研究毫角秒射电结构与扩展射电源中发现的大尺度（远大于1角秒）喷流和叶的关系。