YCAA Seminar - Josefa Becerra Gonzalez

Only around 60 AGNs have been detected so far at Very High Energy (VHE, E>100 GeV) gamma rays, most of them being blazars. Among them only six Flat Spectrum Radio Quasars (FSRQs) have been observed in the VHE band. Despite the difficulty of their detection, FSRQs offer a unique physics scenario to test the AGN structure thanks to their intrinsic gamma-ray absorption within their Broad Line Region (BLR). Gamma-ray blazars are one of the most powerful accelerators of the Universe, and besides the study of their intrinsic properties, they can be used as cosmic lighthouses to probe the cosmic backgrounds as the extragalactic background light (EBL). We will present an overview of the study of VHE FSRQs in a multi-wavelength context as well as the role of VHE blazars on cosmological studies.