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Recent advances in adaptive optics (AO) have led to the implementation of wide field-of-view AO systems. A number of wide-field AO systems are also planned for the forthcoming Extremely Large Telescopes. Such systems have multiple wavefront sensors of different types, and usually multiple deformable mirrors (DMs). Here, we report on our experience integrating cameras and DMs with the real-time control systems of two wide-field AO systems. These are CANARY, which has been operating on-sky since 2010, and DRAGON, which is a laboratory adaptive optics real-time demonstrator instrument. We detail the issues and difficulties that arose, along with the solutions we developed. We also provide recommendations for consideration when developing future wide-field AO systems., Comment: Accepted for publication in MNRAS

EAGLE is the multi-object, spatially-resolved, near-IR spectrograph instrument concept for the E-ELT, relying on a distributed Adaptive Optics, so-called Multi Object Adaptive Optics. This paper presents the results of a phase A study. Using 84x84 actuator deformable mirrors, the performed analysis demonstrates that 6 laser guide stars and up to 5 natural guide stars of magnitude R<17, picked-up in a 7.3' diameter patrol field of view, allow us to obtain an overall performance in terms of Ensquared Energy of 35% in a 75x75 mas^2 spaxel at H band, whatever the target direction in the centred 5' science field for median seeing conditions. The computed sky coverage at galactic latitudes |b|~60 is close to 90%., Comment: 6 pages, to appear in the proceedings of the AO4ELT conference, held in Paris, 22-26 June 2009

Observations made with the University of Durham Mark 6 atmospheric Cerenkov telescope confirm that PSR B1706-44 is a very high energy gamma-ray emitter. There is no indication from our dataset that the very high energy gamma-rays are pulsed, in contrast to the findings at < 20 GeV, which indicate that more than 80% of the flux is pulsed. The flux at E > 300 GeV is estimated to be (3.9 +/- 0.7 (statistical)) x 10^-11 cm^-2 s^-1., Comment: 9 pages, 3 figures, accepted for publication in Astroparticle Physics

The design, construction and operation of the University of Durham ground-based gamma ray telescope is discussed. The telescope has been designed to detect gamma rays in the < 200 GeV region and to achieve good discrimination between gamma ray and hadron initiated showers in the higher energy region (> 300 GeV). The telescope was commissioned in 1995 and a description of its design and operation is presented, together with a verification of the telescope's performance, Comment: 28 pages, 16 figures, accepted for publication in Experimental Astronomy

Centaurus X-3 is a well-studied high-mass accreting X-ray binary and a variable source of high energy gamma rays with energies from 100 MeV to 1 TeV. Previous results have suggested that the origin of the gamma rays is not the immediate vicinity of the neutron star but is sited in the accretion disc, perhaps in an accretion wake. The Durham Mark 6 gamma ray telescope has been used to measure the gamma ray flux from Centaurus X-3 with much higher sensitivity than previous ground-based measurements. The flux above ~ 400 GeV was measured to be (2 +/- 0.3) x 10^-11 cm^-2 s^-1 and appears constant over a period of 2 - 3 months. In 10 hours of observations there is no evidence for periodicity in the detected gamma rays at the X-ray spin period either from a site in the region of the neutron star, or from any other potential site in the orbit., Comment: 11 pages, 4 figures, accepted for publication in Astrophysical Journal

An actively shielded hard X-ray astronomical telescope has been flown on stratospheric balloons. An attempt is made to compare the measured spectral distribution of the background noise counting rates over the energy loss range 20-300 keV with the contributions estimated from a series of Monte Carlo and other computations. The relative contributions of individual particle interactions are assessed.

Following the discovery of Her X-1 as a source of pulsed 1000 Gev X-rays, a search for emission from an X-ray binary containing a pulsar with similar values of period, period derivative and luminosity was successful. The sporadic X-ray binary 4U 0115-63 has been observed, with probability 2.5 x 10 to the minus 6 power ergs/s to emit 1000 GeV gamma-rays with a time averaged energy flux of 6 to 10 to the 35th power.

A new very high energy gamma-ray telescope employing the atmospheric Cerenkov light technique and currently nearing completion is described. The telescope is designed to have capability as both a wide angle instrument (4 degree field of view) for sky survey work and as a narrow field of view instrument (1.35 degrees) for conventional drift-scanning and tracking modes of operation. The telescope consists of two 10 sq. m. mirrors operated in fast coincidence with multiple phototube assemblies at the prime focus of each mirror. The design philosophy of the instrument is discussed and comparisons of its performance with our previous telescopes are made.