Heino Falcke
Today black holes produce the deepest gravitational wells, the hottest plasmas, and likely also the highest energy particles in the universe. The tools of radio astronomy, i.e., innovative new radio interferometers, but also powerful supercomputers, let us study these extreme ends of current physics with unprecedented detail. With current observations we are already approaching the event horizon of black holes, allowing us to study General Relativity and magnetohydrodynamic processes in the most extreme of all environments. We also measure particles with energies $>10^{20}$ eV - the highest ever found - who's acceleration site is likely the hot plasma initially energized and expelled from the immediate environment of black holes. Hence, observations coupled with simulations will allow us eventually to answer some of the fundamental question in todays astrophysics, such as: Does an event horizon exist? How are particles and plasma accelerated and energized to such high energies? What is the source of the enigmatic ultra-high energy cosmic rays?
Amphithéâtre Henri Mineur, Institut d'Astrophysique de Paris