# Korean VLBI Network Calibrator Survey (KVNCS): 1. Source Catalog Of KVN Single Dish Flux Density Measurement In The K And Q Bands

## TL;DR

The KVNCS catalog provides a comprehensive list of radio sources observed at 22 and 43 GHz, aiding high-frequency VLBI calibration with a large, sky-covering sample of compact sources.

## Contribution

This paper presents the first part of the KVNCS, a large-scale survey of radio sources at K and Q bands using the Korean VLBI Network, with detailed flux measurements and source characterization.

## Key findings

- Catalog includes 1533 sources at K band and 553 at Q band.
- Approximately 76% of detected sources are flat-spectrum.
- Most sources are compact and suitable as high-frequency VLBI calibrators.

## Abstract

We present the catalog of the KVN Calibrator Survey (KVNCS). This first part of the KVNCS is a single dish radio survey conducted at 22 (K band) and 43 GHz (Q band) simultaneously using the Korean VLBI Network (KVN) from 2009 to 2011. A total 2045 sources selected from the VLBA Calibrator Survey (VCS) with an extrapolated flux density limit of 100 mJy at K band. The KVNCS contains 1533 sources in the K band with a flux density limit of 70 mJy and 553 sources in the Q band with a flux density limit of 120 mJy; it covers the whole sky down to $-32.^\circ5$ in declination. Five hundred thirteen sources were detected in the K and Q bands, simultaneously; $\sim76\%$ of them are flat-spectrum sources ($-0.5 \leq \alpha \leq 0.5$). From the flux--flux relationship, we anticipated that the most of the radiation of many of the sources comes from the compact components. Therefore, the sources listed in the KVNCS are strong candidates for high frequency VLBI calibrators.