PAGaN II: The Evolution of AGN Jets on Sub-Parsec Scales
  We report first results from KVN and VERA Array (KaVA) VLBI observations
obtained in the frame of our Plasma-physics of Active Galactic Nuclei (PAGaN)
project. We observed eight selected AGN at 22 and 43 GHz in single polarization
(LCP) between March 2014 and April 2015. Each source was observed for 6 to 8
hours per observing run to maximize the $uv$ coverage. We obtained a total of
15 deep high-resolution images permitting the identification of individual
circular Gaussian jet components and three spectral index maps of BL Lac, 3C
111 and 3C 345 from simultaneous dual-frequency observations. The spectral
index maps show trends in agreement with general expectations -- flat core and
steep jets -- while the actual value of the spectral index for jets shows
indications for a dependence on AGN type. We analyzed the kinematics of jet
components of BL Lac and 3C 111, detecting superluminal proper motions with
maximum apparent speeds of about $5c$. This constrains the lower limits of the
intrinsic component velocities to $\sim0.98c$ and the upper limits of the angle
between jet and line of sight to $\sim$20$\deg$. In agreement with global jet
expansion, jet components show systematically larger diameters $d$ at larger
core distances $r$, following the global relation $d\approx0.2r$, albeit within
substantial scatter.
