TY - GEN Y1 - 2008/// ID - heidok9033 N2 - In this work an analysis and interpretation of the Very High Energy (VHE, photon energy > 200 GeV) gamma-ray emission measured from the Active Galactic Nuclei (AGN) PKS 2155-304 is presented. The observations were carried out with the H.E.S.S. telescopes between 2005 and 2007. The source underwent two exceptional flares during this period, on 28 and 30 July 2006. The fluxes observed during these nights are among the highest ever observed in VHE astronomy and provided a very rich dataset. During the first flare the source showed a very fast flux variability (~200 s). No time delays could be observed between the emission at different photon energy bands; this lack of dispersion is used to set limits on the energy scale of Lorentz Invariance violations. The second flare was observed simultaneously by the Chandra X-ray satellite, yielding an unprecedented multi-wavelength view on this object. The most striking result of this night is a cubic decay of the gamma-ray flux as a function of the X-ray flux. Such a correlation can not be explained with current blazar models and points towards an X-ray emission from multiple regions within the AGN. A1 - Buehler, Rolf TI - Two exceptional flares of the active galaxy PKS 2155-304 at Very High Energy gamma-rays and their implications on blazar and fundamental physics AV - public KW - Active Gallaxy KW - Active Galactic Nuclei KW - Quantum Gravity KW - Cosmic Rays UR - https://archiv.ub.uni-heidelberg.de/volltextserver/9033/ ER -