Hunting Very High-energy-emitting (>100 GeV) High-synchrotron-peaked Blazars

Abstract Very high-energy (VHE; >100 GeV) γ -ray emission originates via some of the most extreme particle acceleration processes in the Universe. Considering beamed active galactic nuclei, i.e., blazars, only a small fraction, mainly high-synchrotron-peaked BL Lacertae (BL Lac) objects, have been detected in the VHE band with ground-based Cherenkov telescopes. We utilized ∼16 yr of Fermi Large Area Telescope (LAT) observations in the 0.1−2 TeV energy range to systematically search for potential VHE emitters in a sample of high-synchrotron-peaked ( ν syn peak > 1 0 15 Hz) BL Lac sources. We identified, for the first time, 92 VHE-emitting blazars at a ≥5 σ confidence level. A significant VHE emission was also detected from 52 sources previously reported as VHE blazars. Comparing with the general blazar population, these VHE-emitting blazars are found to be located at low redshifts (mean z = 0.2 ± 0.1) and exhibit bright synchrotron emission ( log F syn peak = − 11.2 ± 0.4 , in erg cm −2 s −1 ). We also investigated the coincidence of VHE photon arrivals with the source activity states and found that Fermi-LAT has detected VHE photons during both quiescent and elevated activity epochs. These VHE-emitting blazars represent promising targets for current and next-generation ground-based Cherenkov telescopes, and provide powerful laboratories for probing particle acceleration in relativistic jets, testing multimessenger connections, and constraining extragalactic background light models.