RUI: Low-Frequency Studies of Active Extragalactic Radio Sources

RUI：主动河外射电源的低频研究

• 批准号: 8715532
• 负责人: Jose Nieves
• 金额: $ 8.45万
• 依托单位: University of Puerto Rico-Rio Piedras
• 依托单位国家: 美国
• 项目类别: Continuing grant
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-05-01 至 1992-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8715532&HistoricalAwards=false
• 关键词: RUI; Low; Frequency; Studies; Active

The objective of this project is to document the low frequency (frequency less than 1 GHz) characteristics of variable extragalactic radio sources. These data will be compared with the predictions of the various mechanisms which have been proposed for this activity. These mechanisms can be divided into: a) Intrinsic variability of a relativistically evolving source, and b) Extrinsic variability due to scattering or absorption in the intervening medium. In order to decide between the hypotheses, observations will be carried out to: a) Continue with the periodic measurements of the flux density of radio sources at low frequencies (318 MHz and 430 MHz), b) Obtain high resolution images of the sources at low frequencies (327 MHz) using Very Long Baseline Interferometry (VLBI), and c) Obtain low frequency (327 MHz) images of these sources at the Very Large Array (VLA). The data base will be augmented by data from a collaboration with other groups working at radio and optical wavelengths. The participation of undergraduate and graduate students in this project, which involves international cooperation and the use of modern and sophisticated techniques, represents for them challenging and rewarding opportunities.

该项目的目标是记录可变河外射电源的低频（频率小于1ghz）特征。这些数据将与为这一活动提出的各种机制的预测进行比较。这些机制可分为：a)相对演化源的内在变异性；b)由于在中间介质中散射或吸收引起的外在变异性。为了在假设之间做出决定，将进行以下观察：a)继续定期测量低频（318兆赫和430兆赫）射电源的通量密度；b)使用甚长基线干涉测量法（VLBI）获得低频（327 MHz）源的高分辨率图像；c)在甚大阵列（VLA）上获得这些源的低频（327 MHz）图像。该数据库将通过与从事无线电和光学波长工作的其他小组合作获得的数据加以扩充。本科生和研究生参与这个涉及国际合作和使用现代和复杂技术的项目，对他们来说是具有挑战性和有益的机会。