What is TANAMI?
Among the most distant objects that we can detect in our Universe are the 'active galactic nuclei' (AGN) at the centers of galaxies that are said to be 'active'. This means that most of the energy they emit does not come from their stars as is the case for 'quiescent' galaxies like our own Milky Way Galaxy. AGN appear to house supermassive black holes millions to billions of times heavier than our Sun. Matter is dragged towards these monster black holes and copious amounts of energy is radiated as this matter swirls around them forming a disk. In a small fraction of AGN some of the matter from near (not inside) the black hole is formed into a pair of tight 'jets' and is flung outwards at speeds very close to that of light. Indeed thanks to a type of optical illusion, jets in several AGN appear to be moving faster than the speed of light! Though we have some good ideas about how all these processes work most of the details are poorly understood. AGN emit all kinds of light from low energy radio and submillimeter waves, through medium energy optical and uv to high evergy light such as X-ray and gamma-ray radation. It has been clear for some time that the key to solving many of these puzzles is to observe all of these types of light coming from AGN and to observe them at the same time. The technique of Very Long Baseline Interferometry (VLBI) which is used to make radio observations is a uniquely useful component of such studies as it provides information at a level of detail that no other technique even gets close to. The TANAMI project uses telescopes of the Australian Long Baseline Array (LBA) as well as telescopes in Antarctica, Chile, South Africa and New Zealand. We are combining these LBA observations with those from NASA's Fermi Gamma-ray Space Telescope, NASA's Swift satellite (which has X-ray, uv and optical telescopes) and ground facilities at optical and infrared wavelengths to understand these edgy cousins of our placid Milky Way Galaxy.
