The trigger system of the MAGIC telescope: on-line selection strategies for Cherenkov telescopes

The Major Atmospheric Gamma-ray Imaging Cherenkov Telescope aims at the detection of very low energy gamma-rays (E > 10 GeV) through the atmospheric emission of Cherenkov light. The high background rate originated by various sources sets a serious challenge to this goal. Application of topological selection cuts at trigger level can contribute to the background reduction, allowing the telescope to operate at lower thresholds and reducing the minimum detectable energy. (C) 2003 Elsevier B.V. All rights reserved