RUI: Low-Frequency Studies of Active Extragalactic Radio Sources

该项目的目标是记录可变河外射电源的低频(频率小于1 GHz)特性。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)相对论演化源的本征可变性，以及b)由于在中间介质中的散射或吸收而引起的外在可变性。为了在假设之间做出决定，将进行观测，以便：a)继续定期测量#年射电源的通量密度低频(318 MHz和430 MHz)，B)使用甚长基线干涉法(VLBI)获得低频(327 MHz)源的高分辨率图像，以及c)在甚大阵列(VLA)上获得这些源的低频(327 MHz)图像。数据库将由与其他从事无线电和光学波长工作的小组合作的数据扩大。本科生和研究生参与这一涉及国际合作和使用现代和尖端技术的项目，对他们来说是具有挑战性的和有益的机会。

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.