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Monitoring of the active galaxy nucleus 3C 66A in the VHE γ-ray and analysis of data in X-rays and optical ranges over the period 1996-2009 were carried out. The nature of processes responsible for one or another type of radiation appeared to be very complicated since, at certain periods of time, an either positive or negative correlation may be observed between different types of radiation. Period of radiation P = 365 days in the X-ray range was found. [ABSTRACT FROM AUTHOR]

The poor angular resolution of imaging γ-ray telescopes is offset by the large reflector areas of next generation telescopes such as MAGIC (17 m diameter), which makes the study of optical emission associated with some γ-ray sources feasible. Furthermore, the extremely fast time response of photomultipliers (PMs) makes them ideal detectors for fast (subsecond) optical transients and periodic sources like pulsars. The optical pulse of the Crab pulsar was detected with the HEGRA CT1 central pixel using a modified PM, similar to the future MAGIC camera PMs.The HEGRA CT1 telescope is a 2.1 m radius Čerenkov telescope, which has seen the Crab optical pulsations. The corresponding observation time required for a detection is 200 s, but MAGIC will only require ∼30 s if the same strategy with standard PMs is used.The constancy of the pulsed fraction (with a relatively small error) during the 2 h CT1 measurements shows that the pointing did not change during the observations. The purpose of these periodic observations was to determine the light of the night sky (LONS) for the galactic anticenter Crab region, and to compare it with the LONS for a nearby bright star (ζ Tauri). These obtained LONS values vary between 4.6 and 4.3 × 1012 ph m-2 s-1 sr-1 (with a coarse estimated error of 10%), being the first value from the timing signature of the Crab pulsar, and the second one was derived from the technique using the ζ Tauri standard star. Our results are between 2.5 and 3 times larger than the previously measured LONS (outside the galactic plane) of (1.7 ± 0.4) × 1012 ph m-2 s-1 sr-1, as expected since the Crab pulsar is in the galactic plane, which implies a slightly higher energy threshold for Crab observations, if the higher value of CT1 measured LONS rate for galactic sources is used. [Copyright &y& Elsevier]

Abstract: The γ-ray large-area space telescope (GLAST) is an astro-particle mission that will study the mostly unexplored, high-energy (20MeV–300GeV) spectrum of photons coming from active sources or diffused in the Universe, with unprecedented resolution and sensitivity. The large field-of-view (FoV) and the broad energy of the GLAST large-area telescope (LAT) are crucial for multi-wavelength campaigns and overlapping observations with ACTs. The construction of the GLAST silicon tracker, with its 83m2 of silicon-strip detectors, by far the largest ever built for a space mission, is now completed. Integration and tests of all the subsystems of the telescope into the satellite will occur during 2006. The launch is scheduled by NASA for October 2007. We report on the tracker design concept, the status of its assembly and on the final results of tests obtained from the full system. [Copyright &y& Elsevier]