FACT - Spectral variability of TeV-blazars

Due to it's ability to measure even under extreme conditions such as full moon nights in combination with it's completely automatic data taking system, the First G-APD Air Cherenkov Telescope (FACT) is well suited for the long term observation of gamma-ray sources. Since the first light in 2011, more than seven years of data from several sources has been acquired, in particular also from two of the brightest TeV-blazars Mrk421 and Mrk501. This allows an unprecedented insight into the variability of these objects. Extracting spectra and combining them with other multi-wavelength data allows to compile time-resolved spectral energy distributions challenging most models. In this context, a recent model is studied. It is based on particle-in-cell (PIC) simulations of reconnection driven plasmoids forming in a blazar's jet. In contradiction to most used steady state models, it directly provides predictions on the temporal behavior which can be compared with experimental data.