Electromagnetic radiation from blazars can be observed from the radio band up to very high energy gamma rays, with spectral energy distributions (SEDs) apparently characterized by a two-bump structure. So far, most of the measured SEDs could be interpreted using simple leptonic origin scenarios, like Synchrotron Self- Compton models. However, models where the gamma rays are due to accelerated protons could also explain the SEDs of blazars. The complex pattern of variability observed in blazars shows extremely short time scales and large amplitudes at the highest energies. Hence, in order to investigate the origin of the emission and the acceleration mechanism in the jet, simultaneous multiwavelength observations are essential. In 2006, multiwavelength campaigns with the Suzaku satellite, sensitive from soft to hard X-rays, and ground based MAGIC/HESS observatories, measuring from energies above 100 GeV to some tens of TeV, were conducted for several northern TeV blazars. Here, the observations made in these campaigns are presented and the measured SEDs will be discussed.

the MAGIC collaboration, the HESS collaboration, the Suzaku team

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. 3 (OG part 2), pages 1029-1032