3C 279: MAGIC telescope observations and multiwavelength behaviour in 2011

The MAGIC experiment, an array of two Cherenkov telescopes located in the Canary Island of La Palma, detects very high energy (VHE, E>100 GeV) γ-rays. The most distant object discovered in this energy range is the flat spectrum radio quasar 3C 279, with redshift z=0.536. Observations in 2011 provided upper limits on the flux above 125GeV. We present the simultaneous multiwavelength behaviour of 3C 279, with observations in the radio, optical, X-ray, high energy and VHE γ-rays. Periods of enhanced activity occur in various energy bands, and a smooth rotation of the optical polarization angle has been measured in coincidence with an optical flare. The broadband spectral energy distribution has been modeled using different leptonic scenarios, all able to reproduce satisfactorily the data. A bent jet model is used to explain the source behaviour at the time of the optical flare; the behaviour predicted by this model is in agreement with our observations.