Broadband characterisation of the very intense TeV flares of the blazar 1ES 1959+650 in 2016

Acciari V. A.; Ansoldi S.; Antonelli L. A.; Arbet Engels A.; Baack D.; Babic A.; Banerjee B.; Barres De Almeida U.; Barrio J. A.; Becerra Gonzalez J.; Bednarek W.; Bellizzi L.; Bernardini E.; Berti A.; Besenrieder J.; Bhattacharyya W.; Bigongiari C.; Biland A.; Blanch O.; Bonnoli G.; Bosnjak Z.; Busetto G.; Carosi R.; Ceribella G.; Chai Y.; Cikota S.; Colak S. M.; Colin U.; Colombo E.; Contreras J. L.; Cortina J.; Covino S.; D'Elia V.; Da Vela P.; Dazzi F.; De Angelis A.; De Lotto B.; Delfino M.; Delgado J.; Di Pierro F.; Do Souto Espineira E.; Dominis Prester D.; Donini A.; Dorner D.; Doro M.; Elsaesser D.; Fallah Ramazani V.; Fattorini A.; Fernandez-Barral A.; Ferrara G.; Fidalgo D.; Foffano L.; Fonseca M. V.; Font L.; Fruck C.; Fukami S.; Gallozzi S.; Garcia Lopez R. J.; Garczarczyk M.; Gasparyan S.; Gaug M.; Godinovic N.; Green D.; Guberman D.; Hadasch D.; Hahn A.; Herrera J.; Hoang J.; Hrupec D.; Inada T.; Inoue S.; Ishio K.; Iwamura Y.; Jouvin L.; Kubo H.; Kushida J.; Lamastra A.; Lelas D.; Leone F.; Lindfors E.; Lombardi S.; Longo F.; Lopez M.; Lopez-Coto R.; Lopez-Oramas A.; MacHado De Oliveira Fraga B.; Maggio C.; Majumdar P.; Makariev M.; Mallamaci M.; Maneva G.; Manganaro M.; Mannheim K.; Maraschi L.; Mariotti M.; Martinez M.; Masuda S.; Mazin D.; Micanovic S.; Miceli D.; Minev M.; Miranda J. M.; Mirzoyan R.; Molina E.; Moralejo A.; Morcuende D.; Moreno V.; Moretti E.; Munar-Adrover P.; Neustroev V.; Niedzwiecki A.; Nigro C.; Nilsson K.; Ninci D.; Nishijima K.; Noda K.; Nogues L.; Nothe M.; Nozaki S.; Paiano S.; Palacio J.; Palatiello M.; Paneque D.; Paoletti R.; Paredes J. M.; Penil P.; Peresano M.; Persic M.; Prada Moroni P. G.; Prandini E.; Puljak I.; Rhode W.; Ribo M.; Rico J.; Righi C.; Rugliancich A.; Saha L.; Sahakyan N.; Saito T.; Sakurai S.; Satalecka K.; Schweizer T.; Sitarek J.; Snidaric I.; Sobczynska D.; Somero A.; Stamerra A.; Strom D.; Strzys M.; Suric T.; Takahashi M.; Tavecchio F.; Temnikov P.; Terzic T.; Teshima M.; Torres-Alba N.; Tsujimoto S.; Van Scherpenberg J.; Vanzo G.; Vazquez Acosta M.; Vovk I.; Will M.; Zaric D.; Hayashida M.

Broadband characterisation of the very intense TeV flares of the blazar 1ES 1959+650 in 2016

Acciari V. A.

•

Ansoldi S.

•

Antonelli L. A.

altro

Hayashida M.

2020

journal article

Periodico

ASTRONOMY & ASTROPHYSICS

Abstract

1ES 1959+650 is a bright TeV high-frequency-peaked BL Lac object exhibiting interesting features like orphan TeV flares and 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) -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 13 and 14 of June, and 1 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 -ray (both Fermi-LAT and VHE bands) and the X-ray bands are quite hard. On 13 June and 1 July 2016, the source showed rapid variations in 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 large values of the Doppler factors (δ ≥ 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 Ljet∼ 1046erg s-1and under high values of the magnetic field strength (∼100 G) and maximum proton energy (∼few EeV). Mixed leptohadronic 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.