Ground based gamma-ray telescopes are providing key observations to explore the non-thermal universe. The High Energy Stereoscopic System (H.E.S.S.) is observing mainly the southern sky from Namibia at very high energies (VHE) of 100 GeV and above.
The data taken during the operation of the telescope have unveiled a rich and diverse population of gamma-ray emitters including Pulsar Wind nebulae, the environment of the super-massive black hole in the heart of the Galaxy, shell type supernova remnants, an X-ray binary, so far unidentified Galactic sources.
Astronomers using Namibia-located telescopes have discovered the first modulated signal from space containing very high-energy gamma rays. This is the first time a signal has been seen at such high energies — 100,000 times higher than previously known.
The way in which the gamma ray signal varies makes LS5039 a unique laboratory for studying particle acceleration near compact objects such as black holes. The matter accelerating around the black hole seems to be creating the plasma jet. The VHE gamma rays thus produced have energies a million times that of visible light. Their association with the central black hole helps us pin down the options for the production of gamma rays in other radio galaxies.
With this and preceding discoveries of extragalactic sources, H.E.S.S. is leading the way in understanding the processes involved in how these extraordinarily energetic photons are produced. These new results can be studied and compared to more numerous, but more distant Blazars where the jet obscures our view of the central source.
Via: Redorbit
