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Synchrotron and Inverse Compton Variability in the BL Lacertae object S5 0716+714

P. Giommi·E. Massaro·L. Chiappetti·E. C. Ferrara·G. Ghisellini·Minhwan Jang·M. Maesano·H. R. Miller·F. Montagni·R. Nesci·P. Padovani·E. Perlman·C. M. Raiteri·S. Sclavi·G. Tagliaferri·G. Tosti·M. Villata
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Abstract

We report intensity variations of different spectral components in the BL Lac object S5 0716+714 detected during coordinated BeppoSAX and optical observations in 1996 and 1998. The transition between synchrotron and inverse Compton emission has been clearly detected as sharp X-ray spectral breaks at around 2-3 keV on both occasions. Correlated optical and soft X-ray variability was found during the second BeppoSAX pointing when intensive optical monitoring could be arranged. The hard (Compton) component changed by a factor of 2 between the two observations, but remained stable within each exposure. During events of rapid variability S5 0716+714 showed spectral steepening with intensity, a behaviour rarely observed in BL Lacs. We interpret these findings as the probable consequence of a shift of the synchrotron peak emission from the IR/optical band to higher energies, causing the synchrotron tail to push into the soft X-ray band more and more as the source brightens.

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P. Giommi, E. Massaro, L. Chiappetti, E. C. Ferrara, G. Ghisellini, Minhwan Jang, M. Maesano, H. R. Miller, F. Montagni, R. Nesci, P. Padovani, E. Perlman, C. M. Raiteri, S. Sclavi, G. Tagliaferri, G. Tosti, M. Villata. 1999-09-14. Synchrotron and Inverse Compton Variability in the BL Lacertae object S5 0716+714. https://arxiv.org/abs/astro-ph/9909241

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