We present the results of the BeppoSAX observations of two BL Lacs, OQ530 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 similar to60 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 similar to3 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.

The BL lacertae objects OQ 530 and S5 0716+714 - Simultaneous observations in the X-rays, radio, optical and TeV bands / Tagliaferri, G.; Ravasio, M.; Ghisellini, G.; Giommi, P.; Massaro, E.; Nesci, R.; Tosti, G.; Aller, M. F.; Aller, H. D.; Celotti, A.; Maraschi, L.; Tavecchio, F.; Wolter, A.. - In: ASTRONOMY & ASTROPHYSICS. - ISSN 0004-6361. - 400:2(2003), pp. 477-486. [10.1051/0004-6361:20021916]

The BL lacertae objects OQ 530 and S5 0716+714 - Simultaneous observations in the X-rays, radio, optical and TeV bands

Ghisellini, G.;Celotti, A.;Tavecchio, F.;
2003-01-01

Abstract

We present the results of the BeppoSAX observations of two BL Lacs, OQ530 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 similar to60 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 similar to3 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.
2003
400
2
477
486
10.1051/0004-6361:20021916
Tagliaferri, G.; Ravasio, M.; Ghisellini, G.; Giommi, P.; Massaro, E.; Nesci, R.; Tosti, G.; Aller, M. F.; Aller, H. D.; Celotti, A.; Maraschi, L.; Ta...espandi
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/20.500.11767/16798
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