The Q-band (43 GHz) Celestial Reference Frame Observed in 2021

Abstract

Our Q-band (43 GHz) celestial reference frame, based on three dual-polarization VLBA sessions from 2021, has 428 sources and 67 thousand observations. The primary goal of these sessions was to compare the structure of the active galactic nuclei (AGN) observed at Q-band (43 GHz) to S, X, and K-bands (2.3, 8.4, and 24 GHz) using nearly concurrent VLBA sessions. The solution presented here was made with the VieVS software on February 09, 2024. Median formal precisions are 203 μas in α cos δ and 353 μas in δ . This Q-band frame is based solely on the all northern geometry of the VLBA. As a result, sky coverage is limited to declinations above −45 deg and precision tends to decrease as one moves south. We are exploring the potential to add Q-band VLBI observations using the Korean tri-band (K, Q, W-band) system. In the far south, we are exploring the baseline from Mopra, Australia to the CART 40-m antenna in Argentina. The prospects for future improvements are bright with the aforementioned potential for adding new stations as well as plans for proposing for more Q-band time on the VLBA, and the planned VLBA upgrade from 4 to 8 Gbps data rates.