VLBI-Gaia Synergy Allows to Find Quasars with An Extremely Low Core Brightness

Recently, statistically significant shifts were discovered between the quasars’ radio coordinates determined by very long baseline interferometry (VLBI) and optical coordinates by Gaia. We conducted a systematic search for quasars in which the shift is due to the fact that the compact radio structure is dominated by a jet brightening parsecs away from the jet’s apparent origin (core), while the core corresponding to the Gaia coordinates is dimmer. We found about 30 objects. Their characteristic core brightness temperature ∼ 109.5 K is an order of magnitude lower than the value for energy equipartition, which questions the energy balance in their jets.