Southern-Hemisphere AGN Monitoring on (Sub-)Parsec Scales: The TANAMI
  Program
  The Very Long Baseline Interferometry (VLBI) monitoring program TANAMI
provides bi-monthly, dualfrequency (8GHz and 22GHz) observations of
extragalactic jets with milliarcsecond resolution south of -30 deg declination
using the Australian Long Baseline Array (LBA) and additional radio telescopes
in Antarctica, Chile, New Zealand and South Africa. Supporting programs provide
multiwavelength coverage of the Fermi/LAT sources of the TANAMI sample, in
order to construct simultaneous broadband spectral energy distributions (SEDs),
as well as rapid follow-ups of high energy flares. The main purpose of this
project is to study the radio-gamma-ray connection seen in the jets of active
galactic nuclei (AGN) via simultaneous monitoring of their VLBI structure and
broadband emission in order to distinguish between different proposed emission
models. Here we give a brief description of the TANAMI program and will then
focus on its current status: (1) We present some results on the first
simultaneous dual-frequency images of the whole sample resulting in spectral
index maps of the parsec-scale core-jet structure. (2) The TANAMI array allows
us to observe the closest radio galaxy Centaurus A with unprecedented high
angular resolution resulting in the best-ever image of an AGN jet. We
constructed the best resolved spectral index map of its jet-counterjet system
revealing multiple possible production sites of gamma-rays recently detected by
Fermi/LAT. With the first epochs of the TANAMI monitoring, we can study the
proper jet motion of individual jet components of Cen A on sub-parsec scales.
(3) Since the launch of Fermi/LAT we added newly detected gamma-ray bright AGN
to the TANAMI observing list which is built as a combined radio and gamma-ray
selected sample. For most of these sources the TANAMI observations obtain the
first VLBI images ever made.
