The QCAL-1 KVN 43 GHz calibrator survey

In December 2011 a VLBI survey of bright compact extragalactic radio sources was made at 43 GHz with the Korean VLBI Network. As a result of this work the catalog of correlated flux densities in three ranges of baseline projection lengths of 637 sources from a 43 GHz (Q-band) was made. Of them, 623 sources have not been observed before at Q-band with VLBI. The goal of this work in the early science phase of the new VLBI array is twofold: to evaluate the performance of the new instrument that operates in a frequency range of 22–129 GHz and to build a list of objects that can be used as targets and as calibrators. We have observed the list of 799 target sources with declinations down to -40°. Among them, 724 were observed before with VLBI at 22 GHz and had correlated flux densities greater than 200 mJy. The overall detection rate is 78%. The detection limit, defined as the minimum flux density for a source to be detected with 90% probability in a single observation, was in a range of 115–180 mJy depending on declination. However, some sources as week as 70 mJy have been detected. Of 623 detected sources, 33 objects are detected for the first time in VLBI mode. We determined their coordinates with the median formal uncertainty 20 mas. The results of this work set the basis for future efforts to build the complete flux-limited sample of extragalactic sources at frequencies 22 GHz and higher at 3/4 of the celestial sphere.


Results of this work are submitted to Astronomical Journal, preprint, paper Leonid Petrov, Sang-Sung Lee, Jongsoo Kim, Taehyun Jung, Junghwan Oh, Bong Won Sohn, Do-Young Byun, Moon-Hee Chung, Do-Heung Je, Seog-Oh Wi, Min-Gyu Song, Jiman Kang, Seog-Tae Han, Jung-Won Lee, Bong Gyu Kim, Hyunsoo Chung, Hyun-Goo Kim, "Early science with Korean VLBI network: the QCAL-1 KVN 43~GHz calibrator survey", Astronomical Journal, 2012, submitted.

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This web page was prepared by Leonid Petrov ()
Last update: 2012.07.26_23:37:41