Speaker
Description
The gamma-ray blazars B2 1811+31 and GB6 J1058+2817 exhibited strong flaring activity in 2020 and 2021, respectively. These high states were observed by the Large Area Telescope on board the Fermi Gamma-ray Space Telescope in the high-energy gamma-ray band (HE, 100 MeV < E < 100 GeV), triggering observations in the very-high-energy gamma-ray band (VHE, E > 100GeV) with the MAGIC telescopes, in the UV and X-rays with the Swift satellite, and in radio and optical bands with several ground-based telescopes. MAGIC telescopes observations led to the first detection at VHE of both sources. In this contribution, we present the details of these detections and the results of the first-time simultaneous multi-wavelength observational campaigns organized for these sources during the flaring states. Long-term gamma-ray light curves were derived using Fermi-LAT data, and the time periods in which the two sources persisted in a quiescent state identified. Archival data collected in the radio to X-ray wavelengths showed that during their low-state periods, both sources exhibited characteristics of intermediate-synchrotron-peaked BL Lacs, which are rather rare sources in the TeV sky. In HE gamma rays, we identified strong spectral hardening and variability on time scales less than a day that provide valuable insights on the gamma-ray emitting regions during the flare.
