The University of Durham New VHE Gamma Ray Telescopes

Very high energy gamma rays from x-ray binary pulsars

“…Confirmation that 4U0115+63 is a VHE gamma ray emitting object was provided by the Whipple and Haleakala VHE telescopes [52,53]. The Whipple telescope observed this source between 1985 September-1986 January and detected one three-day period which showed evidence for the 3.6 s period at a threshold energy of 600 GeV.…”

“…The telescope on Haleakala in the Hawaiian Islands operated by the Universities of Hawaii, Wisconsin and Purdue made observations of Cygnus X-3 for some 133 h during the Summer and Autumn of 1985. On 1985 October 12 (when a pulsar detection was made in Durham), a 60s burst of events was observed from the direction of Cygnus X-3, at phase 0.74 of the 4.8h x-ray cycle [114]. While preliminary analysis of the data taken on October 12 showed some evidence for a 12 ms pulsar signal, a subsequent ab initio period scan of the events occurring within the burst showed no significant evidence for pulsar activity when the large number of degrees of freedom, consequent upon the wide range of periods searched (10 ms-2.2 s), were taken into account.…”

“…University of Durham (Dugway) [49]; +.+ , University of Durham (La Palma) [55]; A, Tata Institute (Gulmarg) [56]; 0, Haleakala Collaboration [53]; + +, Whipple Observatory [52].…”

Development of cold-slumping glass mirrors for imaging Cherenkov telescopes

“…This type of construction is widely utilized in products ranging from doors and tables to aircrafts, boats and satellites and is characterized by high strength-to-weight. The first Cherenkov Telescope employing composite sandwich mirrors had been the MARK 3 experiment, for which a replication process had been developed by making use of aluminum honeycomb core and Alanod ® face sheets [18]. The CANGAROO III telescope, instead, adopts composite sandwich mirrors consisting of rigid foamed core pinched by Fiber Reinforced Plastic sheets; in this case the structure is placed on a mould and curved in an auto-clave for shape replication [19].…”