Cosmic Rays Investigated by Cameras from Olomouc

Eight sites are candidates for construction of two observatories for investigating cosmic rays. The team of scientists from 27 countries participating in the Cherenkov Telescope Array (CTA) project includes experts from Olomouc.

The Czech scientists involved in the project are in charge of night sky monitoring. The researchers have installed automatic full-sky cameras monitoring cloud cover and background of the night sky at several spots located in both hemispheres. The cameras were developed by experts from the Regional Centre of Advanced Technologies and Materials (RCPTM) – Joint Laboratory of Optics at Palacký University in Olomouc and the Physical Institute of the Academy of Sciences of the Czech Republic in Prague.

The full-sky camera records night full-sky pictures with a 180-degree field of view. ‘They provide information on the proportional cloud cover and the degree of brightness at night, which are the most relevant parameters for an observatory,’ said Dušan Mandát on behalf of the Olomouc team.

The Olomouc scientists also test and measure the selected parameters of mirror samples for optical telescopes. They are highly experienced in the production of ultra-thin large-scale mirror segments for a similar project at the Pierre Auger Observatory. The Olomouc laboratory has been testing, for example, the shape of mirrors and their dispersive and mechanical qualities, as well as other parameters. ‘The new observatory will contain a large number of optical telescopes of various sizes in order to create a vast, mutually synchronised detection field,’ explains Mandát.

The collected and analysed data will provide a baseline to assess the eight candidate locations for the Northern and Southern branches of the observatory. The selection committee will choose from locations in Namibia, Argentina, Arizona, Mexico, and Tenerife Island. The selection will be made by the end of 2013.

The goal of the Cherenkov Telescope Array is the research of galactic and extra-galactic gamma ray sources with energies higher than 10 GeV. For comparison, the protons in the European Laboratory for Particle Physics (CERN) have been accelerated to 4 TeV, which is 2,500 times lower energy than the gamma radiation which will be detected by the future CTA observatory.

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