Ponente
Descripción
The discovery of radio galaxies as very high-energy (VHE, E > 100 GeV) gamma-ray emitters is one of the most significant legacy results from the current generation of Cherenkov telescopes. Contrary to the majority of TeV-detected active galactic nuclei, radio galaxies have misaligned jets (θ >10°). Thus, they offer unique views across multiple wavelengths to explore particle acceleration processes and zones without extreme relativistic beaming effects, as well as tools to test fundamental physics and cosmology (e.g. Extragalactic Background Light, Axion-Like Particles, Lorentz Invariance Violation). Bright and rapid TeV flares in nearby radio galaxies reveal intriguing phenomena, challenging conventional models that rely on strong Doppler enhancement.
Here we present the first broadband multi-wavelength study of radio galaxies led by the first Large-Sized Telescope (LST-1) of the Cherenkov Telescope Array Observatory (CTAO), with > 50 hrs from 2022 to 2025 of very-high-energy observations of two nearby (z<0.019) radio galaxies in the Perseus cluster:
NGC 1275 is the bright central galaxy of the Perseus cluster, for which we detect two bright flares, in December 2022 and January 2023, followed by longer quiescent states until present time. Collected contemporary multi-wavelength data reveal the broadband evolution of the source.
IC 310 is a transitional object halfway between a blazar and a radio galaxy, with one of the fastest variabilities recorded in the VHE domain. Our observations reveal a long quiescent state briefly broken by a minor flare in December 2023.
