Abstract :
The gamma-ray extragalactic sky is dominated by blazars, radio-loud active galactic nuclei (AGN) with relativistic jets that are closely aligned with our line of sight. In the MeV range, the Fermi-LAT satellite has led the efforts in studying this violent type of sources, with more than 3000 known blazars discovered so far in the MeV range. In the GeV-TeV range, the Cherenkov experiments MAGIC, HESS and VERITAS have made significant advances in the field. However, their sensitivity has only allowed us to discover ~300 sources in the most extreme Universe after two decades of operations, with only ~90 being AGN and blazars.
The Cherenkov Telescope Array Observatory (CTAO) stems as the future of ground-based gamma-ray astronomy. Its improved capabilities promise to revolutionize the field in the near future. Its first telescope, the Large-Sized Telescope prototype (LST-1), is already operating in La Palma (Spain) since 2018, therefore being not only the future but also the present in the field. In this talk I will give an overview of some of the first scientific results on AGN and blazars obtained during LST-1’s first years of operation. Moreover, some of the software tools developed in the framework of astroparticle physics and gamma-ray astrophysics, with a focus on the importance of multi-wavelength observations, will be briefly outlined. The seminar will conclude with a discussion of future perspectives with the fully operating CTAO.
