Spain and Chile will host next-generation gamma-ray observatory

Spain and Chile will host next-generation gamma-ray observatory
Jul 21, 2015


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Artist's impression of a group of telescopes in the Cherenkov Telescope Array.
(Courtesy: DESY/Milde Science Comm./Exozet)

The Cherenkov Telescope Array will shed light on supernovae[/font]

Sites in Spain and Chile have been chosen to host the Cherenkov Telescope Array (CTA) – a huge gamma-ray observatory 10 times more sensitive than existing instruments, which will study supernova explosions, binary star systems and active galactic nuclei. Astronomers working on the project expect they will get approval at the end of the year to start building the arrays. It is hoped that the CTA will begin taking data at both locations by the end of 2020, with full operations by 2023.

High-energy gamma rays are generated in the most energetic events in the universe, and studying these messengers can reveal important information about the violent processes that created them. When a gamma ray interacts with a particle in the Earth's atmosphere, it produces a shower of lower-energy particles. These particles travel through the atmosphere faster than the speed of light in the atmosphere, creating a cone of blue light akin to a sonic boom. Telescopes on the ground collect this Cherenkov radiation, which scientists then analyse to determine the energy of the original gamma ray and from what direction it came.

The CTA will consist of two arrays. The smaller array – consisting of 15 telescopes 12 m in diameter and four at 23 m – will study the northern sky from the Spanish island of La Palma, which is off the Atlantic coast of North Africa. The larger observatory will have 70 telescopes at 4 m diameter, 25 at 12 m and four at 23 m. It will look toward the southern sky from Paranal in Chile's Atacama Desert, and the first few small telescopes are likely to be deployed to the Chile site in mid-2016.

'Excellent astronomical conditions'

According to CTA project manager and technical director Christopher Townsley from the University of Surrey in the UK, these two sites were chosen over other competitors for several reasons, including the level of existing infrastructure and the estimated long-term operation costs. "Both the sites chosen have well-established observatories nearby and proven excellent astronomical conditions," Townsley explains. If for any reason the La Palma and Paranal site negations fall through, however, the group has alternative north and south locations in Mexico and Namibia, respectively.

More:
http://physicsworld.com/cws/article/news/2015/jul/21/spain-and-chile-will-host-next-generation-gamma-ray-observatory

Science:
http://www.democraticunderground.com/122840648