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During the first year of observations, AGILE detected several blazars, most of them Flat Spectrum Radio Quasars. For a subset of this sample, extensive multi-frequency campaigns were carried out. We report on three FSRQs for which joint AGILE and INTEGRAL observations were requested and obtained: 3C 454.3, 3C 273 and PKS 1830-211. 3C 454.3 is the most active blazar detected by AGILE. It was observed in γ-ray during July 2007, November-December 2007, MayJune 2008, July-August 2008. In November 2007 an INTEGRAL pre-approved AO5 ToO was also activated. As opposite to the gamma-rays, the source was in low state in the hard X-rays. The high gamma-ray state of the source also triggered a Swift ToO at soft X-rays. 3C 273 was observed on December 2007 during coordinated INTEGRAL-AGILE observations planned as open time for INTEGRAL AO5. The source was found to be in high state both in the gammarays and hard Xrays. Also in this case a Swift ToO was activated to monitor the soft X-ray behaviour of the source. Despite of the deep coverage of the galactic plane, PKS 1830-211 was not detected by AGILE on daily or weekly time scales. By accumulating all the available AGILE data, we can provide a deep upper limit (12×10−8 ph cm−2 s−1) for this source at energies above 100 MeV. PKS 1830-211 was extensively observed also by INTEGRAL as a part of AO5 Key Programme, thus providing an unprecedented gamma and hard X-ray monitoring over one year time scale. These data allowed us to investigate possible correlations between the two energy ranges. Moreover, the large multi-frequency coverage involving also radio and optical monitoring (WEBT and REM) of these sources gave us the opportunity to investigate their Spectral Energy Distributions (SEDs) from optical up to gamma-ray energy bands, studying both the synchrotron and inverse Compton emissions. In particular we found that the 3 SEDs are well fitted by a one zone Synchrotron Self Compton (SSC) model plus an External Compton (EC) component which seed photons come from the accretion disk and/or the Broad Line Region (BLR).

Joint INTEGRAL and AGILE observations of FSRQs