CTP Seminar
The unprecedented sensitivity and resolution of Large Area Telescope (LAT) onboard the Fermi Gamma-ray Space Telescope provided insight into the extremely energetic locations of the Universe in the high energy (HE) range from ~50 MeV to ~ 1 TeV. Its fourth source catalog (4FGL) includes 5064 sources. More than 3130 are active galaxies of the blazar class, 239 are pulsars, and 1336 sources have no conceivable counterparts at other wavelengths. On the other hand, at higher energies, the latest generation of the ground-based imaging atmospheric Cherenkov telescope (IACT) arrays detect very high energy (VHE) gamma-ray emission from more than two hundred astrophysical sources both galactic and extra-galactic. This talk is focused on the both detection techniques and provides a summary of the reported sources.