Foschini, L.L.FoschiniGhisellini, G.G.GhiselliniTavecchio, F.F.TavecchioGiommi, PaoloPaoloGiommi2020-09-172020-09-172007-07-01https://hdl.handle.net/20.500.13025/766THE FIRST GLAST SYMPOSIUM. AIP Conference Proceedings, Volume 921, pp. 329-330 (2007).At the end of July 2006, the blazar PKS 2155 - 304 (z = 0.116) underwent a strong outburst observed at TeV energies by HESS (up to 17 Crab flux level at E > 200 GeV). The Swift satellite followed the evolution of the source for about one month. The data analysis - reported in another paper - has shown that, despite the violent activity at TeV energies, the synchrotron energy distribution increased in normalization, but only with a small shift in frequency. In the present work, we fit the broad-band spectrum with a log-parabolic model, to search for indications of intrinsic curvature, which in turn is usually interpreted as a signature of energy-dependent acceleration mechanisms of electrons.10.1063/1.2757336http://adsabs.harvard.edu/abs/2007AIPC..921..329F2007AIPC..921..329F