DOI

https://doi.org/10.48717/efaq-7225

Project

EF033

Title

Potential VLBI phase-ref sources

Abstract

Finding significantly more mas-scale compact and bright active galactic nuclei by blindly targeting known arcsec-scale radio sources would be prohibitively expensive in terms of VLBI resources. On the other hand, a substantial increase in the number of VLBI sources that are also useful as phase-reference calibrators offers huge potential in various science fields, including interplanetary spacecraft navigation, astrophysics, astrometry, and cosmology. With modern large, high-quality optical quasar catalogues and all-sky radio surveys, it is time to investigate whether a highly efficient pre-selection method can guarantee the VLBI detection of certain sources, in large quantities. To test simple selection criteria applied to cross-matched Quaia optical quasars and VLASS sources, we propose X-band snapshot observations of 80 bright (>20 mJy) compact radio sources in two separate fields. Their VLBI detection rate would be characteristic to a sample of ~4000 similar objects. The data will be used to verify and refine the approach that can eventually provide us with up to thousands of prospective new VLBI calibrators all over the sky. We intend to make the calibrated visibility data and images of all the detected sources publicly available for the community.