0620060

We propose a 600 ksec INTEGRAL observation of the gamma-ray blazar 3C 279 simultaneous with XMM-Newton and GLAST/LAT. The main goal is to measure its hard X-ray properties (spectrum variability) in correlation to simultaneous high-energy observations at X- and gamma-ray energies which are guaranteed by an approved XMM-Netwon proposal and by GLAST (assuming proper operation then). These high-energy data of unprecedented sensitivity and energy coverage will be supplemented by ground-based measurements adding finally up to multifrequency spectra of unprecedented accuracy and spectral extent i.e. up to hundreds of GeV. Such high-quality SEDs will provide severe constraints on their modelling and therefore have the potential to discriminate among emission models. Because the observed radiation of 3C 279 is almost purely of non-thermal origin we are studying jet physics including the physics of particle acceleration. [truncated! Please see actual data for full text]