Speaker
Description
We report the detection of a Low Synchrotron Peaked (LSP) blazar PKS 0346-27 at redshift 0.99 by the High Energy Stereoscopic System (H.E.S.S.) on 3rd November, 2021 with a significance above 5σ. The spectral energy distribution (SED) consists of the simultaneous observations by Fermi-LAT, Swift XRT/UVOT and ATOM during the H.E.S.S detection period while the multiwavelength light curve consists of all the observation period. The MWL light curve shows that a flare in high-energy (HE, E > 100 MeV) gamma-rays detected by Fermi-LAT preceded the H.E.S.S. detection by 2 days. A fit with a single-zone emission model to the contemporaneous spectral energy distribution during the detection night was possible with a proton-synchrotron-dominated hadronic model, requiring a proton-kinetic-energy-dominated jet power temporarily exceeding the source’s Eddington limit, although alternative (e.g., multi-zone) models can not be ruled out. Due to strong EBL absorption at the VHE regime, the leptonic model couldn’t provide a satisfactory fit.
Keywords: Galaxies: active, radiation mechanism: non-thermal- relativistic process,
jets: quasars.
