Prototype of new gamma ray telescope inaugurated

Schwarzschild Couder Design could enhance Cherenkov Telescope Array

The Schwarzschild Couder Telescope prototype (pSCT). Credit: Amy Oliver, Fred Lawrence Whipple Observatory, Center for Astrophysics | Harvard & Smithsonian [Source]

A novel gamma-ray telescope could enhance the capabilities of the planned Cherenkov Telescope Array: The prototype of the Schwarzschild Couder Telescope (pSCT) was recently inaugurated at the Fred Lawrence Whipple Observatory (FLWO) in Arizona. DESY is a member of the international consortium that designed and built the telescope.

The Cherenkov Telescope Array will be the world's largest observatory for cosmic gamma radiation and will provide unprecedented insights into the most energetic processes in the universe. It will consist of a total of 118 telescopes, which will be set up at two locations on both halves of the Earth: on the southern hemisphere in the Chilean Andes near the European Southern Observatory ESO and in the north on the Canary Island of La Palma.

In order to cover as wide an energy range as possible, a total of three telescope types of different sizes will be set up. The pSCT is a candidate for the medium-sized CTA telescopes, which are being developed under DESY leadership and will be the “workhorses” of the observatory. “The pSCT optics is an extension option of the first CTA stage and as such is supported by DESY in addition to the standard telescope optics of the medium-sized telescopes,” explains David Berge, head of the gamma astronomy group at DESY. DESY has been operating a prototype of the medium-sized CTA telescopes at the Science Park Berlin-Adlershof since 2013.

The pSCT is based on a 114-year-old concept of the German physicist Karl Schwarzschild (1873-1916), which has only become feasible today due to technical progress. In contrast to conventional gamma-ray telescopes, the pSCT has a double mirror system, which should increase the quality of the focused light and enable the use of compact light sensors. The pSCT main mirror has a diameter of 9.7 meters and consists of 48 mirror elements. The 5.4 meter secondary mirror consists of 24 segments. The engineers have now unveiled the mirrors for the prototype. The telescope is expected to make its first observations this spring.

The pSCT telescope tower and its drive were developed by DESY engineers. The individual components were produced in Europe, then pre-assembled at the DESY site in Zeuthen and sent to the Fred Lawrence Whipple Observatory (FLWO) in Arizona. The tower and drive were installed and commissioned by DESY and FLWO engineers from February to April 2016. The pSCT was made possible by funding through the U.S. National Science Foundation Major Research Instrumentation program and by the contributions of thirty institutions and five critical industrial partners across the United States, Italy, Germany, Japan, and Mexico.

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