The Supernova remnant Cassiopeia A was observed with the 17 meter imaging atmospheric Cherenkov telescope MAGIC for about 50 hours in winter 2006/07. The observations were performed in the so-called wobble mode, under moderated Moon illumination. Above 1 TeV, Cas A has been detected by the HEGRA Stereoscopic Cherenkov Telescope System, at the level of few percent of Crab. The detection of TeV gamma-rays proves that Cas A is a site of CR acceleration for particles - either nucleons or electrons - with multi-TeV energies. A detailed study of the Cas A spectrum and its extention to lower energies, where MAGIC achieves its best sensitivity, will be presented.

MAGIC

Proceedings of the 30th International Cosmic Ray Conference; Rogelio Caballero, Juan Carlos D'Olivo, Gustavo Medina-Tanco, Lukas Nellen, Federico A. Sánchez, José F. Valdés-Galicia (eds.); Universidad Nacional Autónoma de México, Mexico City, Mexico, 2008; Vol. 2 (OG part 1), pages 683-686