Polarimetric Millimeter-VLBI Study of Radio Galaxy M87 and 3C84
Understanding how mass accretion and jet formation occurs near the central engine of AGN has been one of major challenges in modern astrophyiscs. The apparent size of the jet forming region is desperately small even for an extraordinary massive BH system (10Rs=0.001pc for a BH mass of 10^9Msun), making a direct comparison of theories and observations difficult. Therefore, it is indispensable to image the vicinity of the SMBH and the accretion disk with ultra-high resolution VLBI technique. In this talk, I will present an observational study of the innermost region (7 - 100s of Rs) of nearby radio galaxies M87 and 3C 84. The data obtained by global VLBI observations at 86 GHz, with high-sensitivity stations such as the 100m GBT and the IRAM 30m being included, reveal several new features which were not seen by previous VLBI at lower-resolution and/or lower-frequency. Analysis and interpretation of the total intensity and linear polarization structures will be mainly presented.