2003/01/07 by G. Tagliaferri, M. Ravasio, G. Ghisellini +10 · 2 citations
Engineering · Physics and Astronomy · #Astrophysics and Cosmic Phenomena #Particle Accelerators and Free-Electron Lasers #Radio Astronomy Observations and Technology #astro-ph
paper · pdf · doi:10.1051/0004-6361:20021916
10 pages, 8 figures, accepted by A&A
arxiv created 2003/01/07 · openalex publication_date 2003/03/01 · arxiv updated 2009/12/01 · openalex created_date 2022/10/02 · openalex updated_date 2026/07/31
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.