Monte Carlo studies of the GCT for the Cherenkov Telescope Array and the search for VHE AGN using cluster analysis

The future ground based gamma-ray observatory, the Cherenkov Telescope Array (CTA), will soon enter its construction phase. This work therefore looks into providing a better model of one of the small size telescopes, the Gamma Cherenkov Telescope (GCT), for input into Monte Carlo simulations. Evaluation of these models shows that both a telescope equipped with MaPM (GCTM) and SiPM (GCTS) detector modules should meet if not exceed certain CTA requirements. To determine possible early science deliverables, a study into the performance of a small 7 telescope array, along with an extrapolation up to the full complement of SSTs is presented. This reveals promising results for both configurations, with GCTS performing better than GCTM. This work also presents an investigation into the use of local muons as a form of absolute calibration of the GCT telescope. It has been shown that, while there are some difficulties, the method should be possible. The remainder of this thesis presents results obtained from applying the clustering algorithm DBSCAN to the Fermi-LAT data in the very high energy (VHE) regime. This includes 9 sources detected in the Pass 7 reprocessed data set and 70 in the improved Pass 8 data set. These sources represent promising candidates for follow-up observations with current ground-based gamma-ray observatories and helps to frame the science goals of CTA.