Observation of VHE gamma-rays from Cassiopeia A with the MAGIC telescope

Understand

We searched for very high energy (VHE) gamma-ray emission from the supernova remnant Cassiopeia A.

• The shell-type supernova remnant Cassiopeia A was observed with the 17 meter MAGIC telescope between July 2006 and January 2007 for a total time of 47 hours.
• The source was detected above an energy of 250 GeV with a significance of 5.2sigma and a photon flux above 1 TeV of (7.3+-0.7_stat+-2.2_sys)10^-13 cm^-2s^-1.
• The photon spectrum is compatible with a power law dN/dE = A E^-Gamma with a photon index Gamma=2.3+-0.2_stat+-0.2_sys.