Speaker
Description
The location of the blazar zone has been a topic of decades long debate. The only wavelength at which we can spatially resolve the jet is radio, where the jet becomes optically thin several parsecs away from the black hole. It has been generally argued that the main blazar zone is located much closer to the black hole due to the fast variability we see, but also due to lack of seed photons further out. In this talk, I will present recent results from extensive multiwavelength campaigns, demonstrating how the data from radio to VHE gamma-rays was used to pinpoint the location of the blazar zone to the 43GHz VLBI core and possible solutions to the seed photon problem in these cases. I will also discuss why further observations are still needed, also in the CTA era, highlighting the importance of long-term monitoring and multiwavelength support observations, in particular VLBI and optical polarization observations.
