UNI-MB - logo
UMNIK - logo
 
E-resources
Full text
Open access
  • Acciari, V A; Ansoldi, S; Engels, A Arbet; Baack, D; Babić, A; Banerjee, B; U Barres de Almeida; Barrio, J A; Bernardini, E; Berti, A; Bhattacharyya, W; Bigongiari, C; Bonnoli, G; Bosnjak, Z; Busetto, G; Colak, S M; Colin, U; Covino, S; D'Elia, V; De Angelis, A; F Di Pierro; E Do Souto Espiñeira; Donini, A; Dorner, D; V Fallah Ramazani; Fattorini, A; Fernández-Barral, A; Ferrara, G; Fidalgo, D; Foffano, L; Font, L; Fruck, C; Gallozzi, S; García López, R J; Gaug, M; Godinović, N; Green, D; Hahn, A; Hoang, J; Inada, T; Inoue, S; Jouvin, L; Kubo, H; Leone, F; Lindfors, E; López-Coto, R; López-Oramas, A; B Machado de Oliveira Fraga; Majumdar, P; Makariev, M; Maneva, G; Manganaro, M; Mannheim, K; Maraschi, L; Mariotti, M; Martínez, M; Masuda, S; Mazin, D; Minev, M; Mirzoyan, R; Molina, E; Moretti, E; Nilsson, K; Ninci, D; Noda, K; Nöthe, M; Nozaki, S; Palatiello, M; Paoletti, R; Peresano, M; Persic, M; Prada Moroni, P G; Prandini, E; Puljak, I; Rhode, W; Ribó, M; Rico, J; Righi, C; Saha, L; Sahakyan, N; Saito, T; Sakurai, S; Schweizer, T; Šnidarić, I; Sobczynska, D; Somero, A; Stamerra, A; Strom, D; Strzys, M; Surić, T; Tavecchio, F; Temnikov, P; Terzić, T; Teshima, M; Torres-Albà, N; Tsujimoto, S; J van Scherpenberg; M Vazquez Acosta; Vovk, I; Zarić, D

    arXiv.org, 02/2020
    Paper, Journal Article

    1ES 1959+650 is a bright TeV high-frequency-peaked BL Lac object exhibiting interesting features like "orphan" TeV flares and a broad emission in the high-energy regime, that are difficult to interpret using conventional one-zone Synchrotron Self-Compton (SSC) scenarios. We report the results from the Major Atmospheric Gamma Imaging Cherenkov (MAGIC) observations in 2016 along with the multi-wavelength data from the Fermi Large Area Telescope (LAT) and Swift instruments. MAGIC observed 1ES 1959+650 with different emission levels in the very-high-energy (VHE, E >100 GeV) gamma-ray band during 2016. In the long-term data, the X-ray spectrum becomes harder with increasing flux and a hint of a similar trend is also visible in the VHE band. An exceptionally high VHE flux reaching ~ 3 times the Crab Nebula flux was measured by MAGIC on the 13th, 14th of June and 1st July 2016 (the highest flux observed since 2002). During these flares, the high-energy peak of the spectral energy distribution (SED) lies in the VHE domain and extends up to several TeV. The spectrum in the gamma-ray (both Fermi-LAT and VHE bands) and the X-ray bands are quite hard. On 13th June and 1st July 2016, the source showed rapid variations of the VHE flux within timescales of less than an hour. A simple one-zone SSC model can describe the data during the flares requiring moderate to high values of the Doppler factors (>=30-60). Alternatively, the high-energy peak of the SED can be explained by a purely hadronic model attributed to proton-synchrotron radiation with jet power L_{jet}~10^{46} erg/s and under high values of the magnetic field strength (~100 G) and maximum proton energy (~few EeV). Mixed lepto-hadronic models require super-Eddington values of the jet power. We conclude that it is difficult to get detectable neutrino emission from the source during the extreme VHE flaring period of 2016.