How far is M87 from Earth

Gamma radiation discovered from the edge of a supermassive black hole

Notes on H.E.S.S.


The research group: The international research group of the High Energy Stereoscopic System (H.E.S.S.) includes scientists from Germany, France, Great Britain, the Czech Republic, Ireland, Armenia, South Africa and Namibia.

The experiment: The results were obtained with the telescopes of the High Energy Stereoscopic System (H.E.S.S.) in Namibia (South-West Africa). This system, consisting of four telescopes with a mirror diameter of 13 m each, is currently the most sensitive experiment for measuring very high-energy, cosmic gamma radiation. This radiation is absorbed in the earth's atmosphere, creating a short-lived shower of many millions of particles. The particles emit very short (a few nanoseconds) and weak flashes of light (so-called Cherenkov light), which is recorded by the extremely sensitive cameras of the H.E.S.S. telescopes. Each image corresponds to a single gamma photon and its energy can be determined from the amount of light recorded. By combining all the recorded events, you get a picture of the sky at very high energies.

The H.E.S.S. telescopes were built over several years by an international team of over 100 scientists and technicians. The experiment was inaugurated in September 2004 by the Namibian Prime Minister Theo-Ben Guirab and the first results already represented important discoveries, such as the first astronomical image of a shock wave in a supernova in the highest gamma energies.

Plans for the future: The H.E.S.S. participating scientists continue to work on expanding and improving the telescopes. The installation of another, huge central telescope with a mirror diameter of 30 m (!) Has begun, with other partner countries, such as Poland, having joined. The improved system (called H.E.S.S.-II) will be even more sensitive and at the same time cover a larger energy range of gamma radiation, so that the catalog of high-energy gamma sources will be expanded to include numerous objects.