Korean VLBI Network (KVN)

2015 Seminar List:

01/23/2015   01/30/2015   02/13/2015   02/27/2015   03/20/2015   04/10/2015   05/08/2015   05/15/2015   05/22/2015   05/29/2015   06/05/2015   06/12/2015   07/03/2015   07/24/2015   07/31/2015   08/07/2015   08/28/2015   09/04/2015   09/18/2015   09/25/2015   10/02/2015   10/30/2015   11/06/2015   11/27/2015  

Dr. Guang-Yao Zhao
KVN Group
KVN source-frequency phase-referencing observations of 3C 66A&B

Both 3C66 A and 3C 66B are interesting radio sources. The separation on the sky plane between them is very small.

Previous VLBA observation results indicate non-stationarity of the core may exist in one or both sources.

We have carried out 6-epoch SFPR observation of 3C 66A&B with the KVN. Two more sources were included as secondary phase-referencing calibrators and each source was observed at 22, 43, and 86 GHz simultaneously. Our preliminary results show that after frequency phase transfer from the lower frequency, the phase of each source at higher frequencies became more aligned, i.e. the coherence time becomes longer.

After all the calibration, the SFPRed maps and combined core-shift measurements are obtained. The measurements are found to be affected by structural blending effect because of the large beamsize of KVN. So we have carried out KaVA observations to overcome this issue. It is found the combined core-shift does not change significantly over a timescale of 2 months but the relative core position at each frequency has changed. The reason could be inner-jet structural change or real SMBH motion. Further analysis of the next few epochs may help reveal the nature of this motion.

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Korean VLBI Network