Tagliaferri, G.G.TagliaferriRavasio, M.M.RavasioGhisellini, G.G.GhiselliniGiommi, PaoloPaoloGiommi2020-09-172020-09-172003-03-01https://hdl.handle.net/20.500.13025/177Astronomy and Astrophysics, v.400, p.477-486 (2003)We present the results of the BeppoSAX observations of two BL Lacs, OQ 530 and S5 0716+714, as part of a ToO program for the simultaneous observation at radio, optical, X-ray and TeV energies. Both sources are detected in the LECS and MECS, with S5 0716+714 visible also in the PDS band, up to about ~ 60 keV. The X-ray spectra of both sources are better fitted by a double power-law model, with a steep soft X-ray component flattening at harder energies, with breaks at 0.3 and 1.5 keV, respectively. The concave shape of the spectra in both objects is consistent with soft X-rays being produced by the synchrotron and harder X-rays by the inverse Compton processes. Also the X-ray variability properties confirm this scenario; in particular, for S5 0716+714 our observation shows variations by about a factor of 3 over one hour below ~ 3 keV and no variability above. Their simultaneous broad-band energy spectral distributions can be successfully interpreted within the frame of a homogeneous synchrotron and inverse Compton model, including a possible contribution from an external source of seed photons with the different spectral states of S5 0716+714 being reproduced by changing the injected power. The resulting parameters are fully consistent with the two sources being intermediate objects within the ``sequence" scenario proposed for blazars.BL Lacertae objects generalX-rays galaxiesBL Lacertae objects individual OQ 530S5 0716+71410.1051/0004-6361 20021916http://adsabs.harvard.edu/abs/2003A&A...400..477T2003A&A...400..477T