J1128+592: a highly variable IDV source
J1128+592: a highly variable IDV source
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DOI：
10.1002/asna.200710818
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发表时间：
2007-05
影响因子：
0.9
通讯作者：
K. Gabányi;N. Marchili;T. Krichbaum;S. Britzen;L. Fuhrmann;A. Witzel;J. Zensus;P. Muller;X. Li
中科院分区：
文献类型：
--
作者：
K. Gabányi;N. Marchili;T. Krichbaum;S. Britzen;L. Fuhrmann;A. Witzel;J. Zensus;P. Muller;X. Li
致密河外射电类星体和耀变体的短时间尺度射电变化被称为日内变化（IDV），至少在某些来源中可以解释为传播效应;这些变化被解释为银河系湍流星际介质中的无线电波闪烁。最有说服力的观测参数之一，有利于传播引起的变化的情况下，是观察到的年度调制的特征时间尺度的变化，由于地球的轨道运动。到目前为止，只有两个已知的来源具有良好的季节性周期。对于其他几个记录不太完整的天体，也提出了年度调制的建议。然而，对于其他一些IDV源，源内在结构的变化，导致急剧变化的变异性时间尺度也提出了建议。J1128+592是最近发现的高度可变的IDV源。以前，使用Effelsberg 100米射电望远镜（德国）和乌鲁木齐25米射电望远镜（中国）进行的密集时间采样通量密度测量强烈表明时间尺度的年度调制。然而，2006/7年的最新4次观测结果与之前提出的年调制模型不太符合。在本文中，我们调查了这种差异的可能解释。（© 2007 WILEY-VCH Verlag GmbH & Co. KGaA，魏因海姆）
Short time-scale radio variations of compact extragalactic radio quasars and blazars known as IntraDay Variability (IDV) can be explained in at least some sources as a propagation effect; the variations are interpreted as scintillation of radio waves in the turbulent interstellar medium of the Milky Way. One of the most convincing observational arguments in favor of a propagation-induced variability scenario is the observed annual modulation in the characteristic time scale of the variation due to the Earth's orbital motion. So far there are only two sources known with a well-constrained seasonal cycle. Annual modulation has been proposed for a few other less well-documented objects. However, for some other IDV sources source-intrinsic structural variations which cause drastic changes in the variability time scale were also suggested. J1128+592 is a recently discovered, highly variable IDV source. Previous, densely time-sampled flux-density measurements with the Effelsberg 100-m radio telescope (Germany) and the Urumqi 25-m radio telescope (China), strongly indicate an annual modulation of the time scale. The most recent 4 observations in 2006/7, however, do not fit well to the annual modulation model proposed before. In this paper, we investigate a possible explanation of this discrepancy. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)