제목 : The Plasma-Physics of AGN on (Sub)Parsec Scales
연사 : Sasacha Trippe 교수님 (서울대학교)
언어 : English
"The Korean VLBI Network (KVN) is capable of simultaneous multi-frequency full polarization observation observations. This makes the KVN ideal for studying the jet physics of radio-bright active galactic nuclei, especially blazars.
Firstly, I present results of a monitoring study of BL Lacertae from 2013 to 2016. BL Lac's radio core shows an exponential decay of brightness over time, with the decay time scale depending on frequency. The resulting scaling law suggests that the (sub-)mm radio core is a standing re-collimation shock.
Secondly, I present the first systematic study of multi-frequency blazar polarization with KVN. We have been able to obtain high-quality linear polarization data for several sources, with typical degrees of polarization being on the order of few per cent. Faraday rotation measures (RM), which probe particle densities and magnetic field strengths, are on the order of thousands of of rad per square meter. The evolution of RM with frequency suggests that jet bases are either spherical or conical."