The last few years have seen dramatic new results in the field of TeV gamma-ray astronomy, shedding new light on particle acceleration
and non-thermal radiation processes in a range of astrophysical objects; shell-type supernova remnants, molecular clouds,
pulsar-wind nebulae (PWN),
compact binary systems, nearby active galactic nuclei (AGN) and radio galaxies. In addition, several TeV sources remain unidentified, with no clear
counterpart at any other energies. These results have furthered our knowledge of several modern astrophysics and cosmological issues such as the role of
SNR shocks in the production of Galactic cosmic-rays, the production of pulsar winds and their interaction with the
interstellar medium, the variable particle acceration environments of compact binary systems,
particle acceleration in supermassive black holes and the level of extragalactic background radiation in the nearby (z < 0.2) Universe.
The key technical advance in this field is the ground-based stereoscopic atmospheric Cherenkov imaging technique, employed in arrays of imaging atmospheric Cherenkov telescopes (IACTs) such as H.E.S.S., CANGAROO-III and VERITAS, which are optimised for the 0.1 to several 10's of TeV energy range. The great success of H.E.S.S., for example, has clearly established this technique as by far the most sensitive tracer of non-thermal particle acceleration, and has led to the development of future detectors with coverage in unexplored energy ranges. New instruments (eg. H.E.S.S.-II, MAGIC-II) designed for the sub-0.1 TeV range are under construction, and will probe the exciting high energy astrophysics of, for example, pulsars, gamma-ray bursts and AGN at increasing distances. Larger-scale long-term projects are also being discussed amongst present collaborations.
In the higher energy domain, E>10 TeV, gamma-ray astronomy is also able to tackle fundmental astrophysical questions concerned with the nature of particle acceleration at PeV (10^15 eV) energies and beyond. At PeV energies, around the so-called knee of the cosmic-ray energy spectrum, there are no convincing theories as to how particles are accelerated. Some hints might be available as many of the known Galactic TeV sources have unbroken energy spectra extending to E~10 TeV, guaranteeing the presence of sources for study at higher energies. The same technique, as used in H.E.S.S. and others, is in fact perfectly-suited to gamma-ray detection at higher energies well above 10 TeV, and there is considerable interest in developing arrays of IACTs specifcally for this purpose. Their potentially simple design yet sensitive performance, and modest size and cost, make such telescopes a very attractive future activity in high energy astrophysics, with short time-scale development.
A key focus of this workshop is to discuss the development of a large array of imaging atmosperic Cherenkov telescopes (IACTs) optimised for energies E>10 TeV. The High Energy Astrophysics Group at the University of Adelaide, is actively involved in this development, planning a precursor IACT array of 4 to 5 telescopes. This workshop will serve to highlight the potential of this exciting new activity in high energy astrophysics and bring together experts in IACT development, high-energy astrophysicists, and interested groups, aiming to identify future collaboration for a new IACT array. To set the scene, we will also review results and developments in TeV gamma-ray astronomy and related fields such as X-ray, cosmic-ray and neutrino astronomy.