Blazars at Very High Energies: Emission Modelling

Blazars are very broadband cosmic sources with spectra spanning over twenty orders of magnitude in frequency, down to the 100 MHz regime radio range, up VHE at several tens TeV. The modelling their spectral energy distribution high energies currently considers two main classes models, leptonic and lepto-hadronic, which both succeed fairly well describing observed for populations blazars, namely BL Lac objects (BL Lacs) flat spectrum quasars (FSRQs). However they confronted difficulties, particular reproduce flaring phenomena monitored a good multi-spectral temporal coverage, or extreme challenge basic descriptions. Such situation has led diversity specific scenarios, positioning relation general context is generally not clearly fixed. identification dominant particle acceleration mechanism work better understanding location TeV emitting zone would make it possible break degeneracies between models. Multi-wavelength multi-messenger studies should also help this regard, perspective elaborate reference scenario blazars AGNs.