TeV Gamma Rays from Active Galactic Nuclei

                        Trevor C. Weekes
                      Whipple Observatory,
           Harvard-Smithsonian Center for Astrophysics

Blazars are a sub-class of Active Galactic Nuclei in which the
jet associated with the massive black hole is directed towards
the solar system. It is generally believed (based on indirect
evidence) that the jets contain beams of relativistic particles
and that these are likely sources of extragalactic cosmic rays.
It should come as no surprise that many of these blazars have
been detected as 100 MeV gamma-ray sources by EGRET on the
Compton Gamma Ray Observatory. It is more surprising that these
sources dominate the sky at TeV energies where the gamma rays are
detected by ground-based atmospheric Cherenkov telescopes. Time
variations as short as 15 minutes have been seen. The energy
spectrum extends at least to 10 TeV. The current observational
status of TeV astronomy will be described and the promise for the
future, with the development of new telescopes in space (GLAST)
and on the ground (VERITAS), will be emphasized.