We observed one of the most promising PeVatron candidates, SNR G106.3+2.7 with the MAGIC telescope for 122 hours in total between May 2017 and August 2019.
%In the radio continuum emission, this source has a cometary shape with the head and the tail region.
%The analysis energy threshold is $\sim 0.2$ TeV, and the angular resolution is $0.07 - 0.1^\circ$.
We detected extended $\gamma$-ray emission spatially coincident with the radio continuum, which exhibits a cometary shape with a head and a tail region.
A significant $\gamma$-ray emission with energies above 6.0 TeV was detected only from the tail region, suggesting that the emissions above 10 TeV, detected with air shower experiments (Milagro, HAWC, Tibet ASγ and LHAASO), are from the tail. With this assumption, it is possible to explain the multi-wavelength spectrum of the head region with either a hadronic or leptonic model. Instead, the leptonic model fails to explain the $>10 TeV$ and X-rays emission of the tail simultaneously, while the hadronic model can reproduce the observed spectrum at the tail with a power-law proton spectrum of a power law with a cutoff energy at $\sim 1$ PeV.