Observations of W51 with the MAGIC telescopes

W51 located at the Sagittarius arm of the milky way at a distance of 5.5 kpc is a well-known star-forming region hosting both a supernova remnant molecular cloud association and a possible pulsar wind nebula. High energy gamma-ray emission was reported from Fermi/LAT as well as very high energy gamma-ray emission was detected by the H.E.S.S. collaboration. Previous measurements could not reveal the spatial origin of the extended emission. The spectrum obtained by Fermi/LAT however suggests a hadronic origin of the emission. The VHE observations presented here, obtained with MAGIC stereo system, allow us to pinpoint the VHE gamma-ray emission to the interaction region between the remnant and the molecular cloud. The MAGIC data also allow us to measure, for the first time, the VHE emission spectrum of W51 from the highest Fermi/LAT energies up to several TeV.