Launch of the first telescope from the Cherenkov Telescope Array Site
Last Tuesday, October 10, the first large-sized telescope of the Cherenkov Telescope Array (CTA) was inaugurated. The telescope, named LST-1, is the first of four telescopes with such features to be arranged in the Observatorio del Roque de los Muchachos (La Palma, Canary Islands).
Last Tuesday, October 10, the first large-sized telescope of the Cherenkov Telescope Array (CTA) was inaugurated. The telescope, named LST-1, is the first of four telescopes with such features to be arranged in the Observatorio del Roque de los Muchachos (La Palma, Canary Islands).
The LST team is formed by more than two hundred scientists from ten countries among which are the Catalan research centers that participated in the technological development of LST-1 and contributed to the definition of scientific objectives of the project. The Institute for Cosmos Sciences of the UB (ICCUB-IEEC) also contributed to the design of one of the signal amplifier devices. The Institute for High Energy Physics (IFAE) was in charge of the coordination, control and assembly of the LST-1 camera and the design and assembly of the mechanic system that allows turning the telescope and anchor it to the ground. The Institute of Space Sciences (IEEC-CSIC) took part in the development of the control software and the scheduler.
Gamma ray detection
Since low energy gamma rays produce a small amount of Cherenkov light, two telescopes with large mirrors are required to capture the images. Therefore, four LST telescopes will be placed in the northern and southern area of the CTA observatory, managed by the Canary Islands Institute of Astrophysics, to cover the low-energy sensitivity between 20 and 150 GeV of CTA. Apart from the LST, two more telescopes are required to study the energy range from 20 gigaelectronvolt (GeV= to 300 teraelectronvolts (TeV): medium-sized telescopes and small-sized telescopes. Once this is finished, the northern network will be formed by fifteen other medium-sized telescopes (MSTs).
The LST has a 23-metre diameter parabolic reflective surface, supported by a tubular structure made of carbon fiber and steel tubes. The 400 square meter reflective surface collects and focuses the Cherenkov light to the camera, where photomultiplier tubs turn the light into electrical signals that are processed by dedicated electronics. Although the LST-1 stands 45meters tall and weighs about 100 tons, it is extremely fast and can re-position within 20 seconds to capture brief, low-energy gamma ray signals.
LST will expand the science reach to cosmological distances and fainter sources. Both the re-positioning speed and the low energy threshold these provide are key elements in the study of transient gamma-ray sources in our Galaxy and the study of active galactic nuclei and gamma-ray bursts at high redshift.