High Energy Stereoscopic System

HESS is a redirect to this article. For further meanings of the letter sequence, see Hess .

Coordinates: 23 ° 16 ′ 0 ″  S , 16 ° 30 ′ 0 ″  E

The HESS II Telescope Array

The logo of the HESS collaboration

The telescopes CT-2 and CT-3

Four telescopes in operation at night

The High Energy Stereoscopic System or HESS is a system of imaging Cherenkov telescopes (IACTs) for the investigation of cosmic gamma radiation in the energy range between 30 GeV and a few 10 TeV. The acronym was chosen in honor of Victor Franz Hess , who was the first to detect cosmic rays .

The name continues to emphasize two main features of the system, namely the simultaneous observation of air showers with several telescopes and the grouping of all telescopes into a common system in order to lower the energy threshold and increase the effective detection area for gamma radiation. HESS enables the investigation of gamma radiation sources with intensities in the range of less than 1% of the Crab Nebula .

HESS is operated on the Göllschau farm in Namibia near the Gamsberg . The area is known for its particular aptitude for optical observations.

history

The first of the four telescopes from phase I of the HESS project was put into operation in summer 2002; since December 2003 all four telescopes have been operated together. The system was officially inaugurated on September 28, 2004.

In 2004, HESS was the first IACT experiment to spatially resolve the structure of a source of cosmic gamma radiation . In 2005, HESS discovered eight new sources of high-energy gamma radiation and thus doubled the number of known sources. Two of these sources have not yet been identified with known objects such as supernova remnants or pulsars . The existing structure was expanded by a telescope with a diameter of 28 meters by July 2012 (HESS Phase II). Originally it was planned to expand the facility by 12 more telescopes of the same size as the four previous to 16 telescopes. However, this plan was abandoned for financial reasons.

The first light from HESS II was on July 26th, 2012. With one of only two measurements worldwide, HESS II recorded gamma radiation from the Vela pulsar at the beginning of July .

Gamma radiation sources found by HESS (assembly)

construction

HESS from a bird's eye view (2017)

Aerial photograph of the HESS (2018)

The four telescopes of phase I stand on the corners of a square 120 m long. The mirrors of the telescopes each consist of 382 round mirror facets with a diameter of 60 cm. This results in a total mirror area of ​​108 m² per telescope, corresponding to the area of ​​a single mirror with a diameter of 11.73 m.

The fifth phase II telescope is at the intersection of the diagonals of the phase I telescopes. The mirror consists of 875 hexagonal mirror facets with a diameter of 90 cm. The total mirror area is 614 m² and the total height is approx. 40 m. The total weight is 600 t. Thus, it is currently the largest reflector telescope on earth.

Participating German research institutes

• Max Planck Institute for Nuclear Physics , Heidelberg
• Erlangen Center for Astroparticle Physics (ECAP) at the University of Erlangen-Nuremberg
• Working group experimental elementary particle physics at the Humboldt University Berlin
• Faculty for Physics and Astronomy at the Ruhr University Bochum
• Institute for Experimental Physics at the University of Hamburg
• State Observatory Heidelberg-Königstuhl of the University of Heidelberg
• Institute for Astronomy and Astrophysics at the University of Tübingen
• DESY , Zeuthen site

See also

• Astronomy in Namibia

literature

• Heinrich J. Völk : New results in gamma astronomy. In: Stars and Space, Vol. 8/2006, pp. 36–45

Web links

Commons : HESS  - collection of images, videos and audio files

• HESS ( Memento from July 4, 2012 in the Internet Archive ) unam.na
• High Energy Stereoscopic System Project (HESS) on the Internet
• Science : A new population of very high energy gamma-ray sources in the Milky Way
• New Scientist : Number of very high-energy gamma ray sources doubles
• www.astroteilchenphysik.de

Individual evidence

1. ↑ Largest ever Cherenkov telescope sees first light mpi-hd.mpg.de; “First Light” for HESS-II pro-physik.de, accessed on July 27, 2012
2. ↑ 5.7.2014 News in the evening. Hitradio Namibia, July 5, 2014 ( Memento from July 10, 2014 in the web archive archive.today )
3. ↑ The HESS Telescopes
4. ↑ Looking further into space. Allgemeine Zeitung, July 30, 2012
5. ↑ Namibia leads the way in space observation. The Namibian, July 30, 2012