[KSCI] Korea Science Citation Index Service

http://dx.doi.org/10.5303/PKAS.2022.37.1.001

REEVALUATION OF KVN GAINS

Cheong, Whee Yeon (University of Science and Technology)
Kim, Sang-Hyun (University of Science and Technology)
Lee, Sang-Sung (University of Science and Technology)
Byun, Do-Young (University of Science and Technology)
Jung, Taehyun (Korea Astronomy and Space Science Institute)

Publication Information

Publications of The Korean Astronomical Society / v.37, no.1, 2022 , pp. 1-11 More about this Journal

Abstract

During the course of analysing both single-dish and very long baseline interferometry (VLBI) data obtained from the Korean VLBI Network (KVN), we found a systematic offset between flux density measurements from different antennas. We were able to attribute a majority of the systematic offsets to changes in the "a priori" antenna gains, which were found to have varied up to 10 percent at 22 GHz and up to 30 percent at 43 GHz. Using historical calibrator observations, we present a revised set of gains that may be applied to KVN data taken from 2015 August to 2019 January. Application of the revised gains to the KVN results in a consistency of correlated flux density measurements between the three baselines of approximately five percent. We found that images from the recalibrated data typically have a 50 percent higher dynamic range, with some cases showing an increase of dynamic range of up to a factor of three.

Keywords

telescopes; techniques: miscellaneous; methods: observational;

Citations & Related Records

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