[Colloquium] Recent Advances in AGN Jet Studies Enabled by the Global VLBI Alliance

© Jongho Park

Very Long Baseline Interferometry (VLBI) achieves ultrahigh angular resolution by utilizing widely separated radio telescopes. The quality of VLBI images improves with more participating telescopes, a principle realized by the Global VLBI Alliance (GVA). In this talk, I will present recent advances in AGN jet studies enabled by the GVA.

(1) We identified a dense, cold ambient medium near the core of the 3C 84 jet, which guides its propagation on parsec scales and significantly influences its overall shape.

(2) Our observations of NGC 315 reveal that its jet, previously known for a center-brightened morphology at parsec scales, is actually edge-brightened—a feature unresolved in earlier VLBI studies.

I will discuss the physical implications of these findings and explore future research opportunities with the GVA.