V-FASTR: THE VLBA FAST RADIO TRANSIENTS EXPERIMENT
V-FASTR: THE VLBA FAST RADIO TRANSIENTS EXPERIMENT
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DOI：
10.1088/0004-637x/735/2/97
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发表时间：
2011-04
期刊：
影响因子：
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通讯作者：
R. Wayth;W. Brisken;A. Deller;W. Majid;D. Thompson;S. Tingay;K. Wagstaff
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文献类型：
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作者：
R. Wayth;W. Brisken;A. Deller;W. Majid;D. Thompson;S. Tingay;K. Wagstaff
最近用单碟射电望远镜发现了分散的、非周期的脉冲射电信号，这激发了人们对探索相对未知的快速瞬态射电信号空间的极大兴趣。在这里，我们描述了V-FASTR，一个使用甚长基线阵列（VLBA）进行快速瞬态无线电信号盲搜索的实验。实验完全在共频模式下运行，同时进行正常的VLBA观测和操作。这是由用于处理VLBA数据的DiFX软件相关器的功能和灵活性所实现的。与单碟实验相比，使用VLBA进行这种类型的实验具有显著的优势，包括更大的视野，能够轻松地将本地射频干扰与真实信号区分开来，以及将天空中检测到的事件定位到毫秒精度的可能性。我们描述了我们的软件管道，它在相关期间实时接收来自每个天线的短集成（~ ms）光谱仪数据，并在一系列试验色散测量中分别对每个天线执行非相干去色散。分散的数据由一个复杂的探测器处理，并记录候选事件。在关联结束时，存储事件发生时的原始数据的小片段，以供进一步分析。我们给出了对脉冲星B0329+54和B0531+21（蟹状脉冲星）的一些测试观测的事件探测管道的结果。
Recent discoveries of dispersed, non-periodic impulsive radio signals with single-dish radio telescopes have sparked significant interest in exploring the relatively uncharted space of fast transient radio signals. Here we describe V-FASTR, an experiment to perform a blind search for fast transient radio signals using the Very Long Baseline Array (VLBA). The experiment runs entirely in a commensal mode, alongside normal VLBA observations and operations. It is made possible by the features and flexibility of the DiFX software correlator that is used to process VLBA data. Using the VLBA for this type of experiment offers significant advantages over single-dish experiments, including a larger field of view, the ability to easily distinguish local radio-frequency interference from real signals, and the possibility to localize detected events on the sky to milliarcsecond accuracy. We describe our software pipeline, which accepts short integration (∼ ms) spectrometer data from each antenna in real time during correlation and performs an incoherent dedispersion separately for each antenna, over a range of trial dispersion measures. The dedispersed data are processed by a sophisticated detector and candidate events are recorded. At the end of the correlation, small snippets of the raw data at the time of the events are stored for further analysis. We present the results of our event detection pipeline from some test observations of the pulsars B0329+54 and B0531+21 (the Crab pulsar).