SIMBAD references

The direction of parsec-scale jets in active galactic nuclei (AGNs) is essential information for many astrophysical and astrometric studies, including linear polarization and magnetic field structure, frequency-dependent synchrotron opacity, proper motion, and reference-frame alignment. We developed a rigorous, simple, and completely automated method to measure the directions from calibrated interferometric visibility data at frequencies ranging from 1.4 to 86 GHz. We publish the results for 9220 AGNs with the typical accuracy below 10°. An internal check of the method comparing the directions between different observing frequencies as well as with previous publications verifies the robustness of the measured values.