The blazar TXS 0506+056 associated with a high-energy neutrino: insights into extragalactic jets and cosmic ray acceleration

S. Ansoldi , L.A. Antonelli , Lucio Angelo Antonelli , Cornelia Arcaro , Dominik Baack , Ana Babić , Biswajit Banerjee , Priyadarshini Bangale , Ulisses Barres de Almeida , Juan Abel Barrio , Josefa Becerra González , Wlodek Bednarek , Elisa Bernardini , Alessio Berti , Wrijupan Bhattacharyya , Adrian Biland , Oscar Blanch , Giacomo Bonnoli , Roberto Carosi , Alessandro Carosi , Giovanni Ceribella , Anshu Chatterjee , Sidika Merve Colak , Pierre Colin , Eduardo Colombo , Jose Luis Contreras , Juan Cortina , Stefano Covino , Paolo Cumani , Paolo da Vela , Francesco Dazzi , Alessandro de Angelis , Barbara de Lotto , Manuel Delfino , Jordi Delgado , Federico Di Pierro , Alberto Domínguez , Dijana Dominis Prester , Daniela Dorner , Michele Doro , Sabrina Einecke , Dominik Elsaesser , Vandad Fallah Ramazani , Alba Fernández-Barral , David Fidalgo , Luca Foffano , Konstantin Pfrang , Maria Victoria Fonseca , Lluis Font , Christian Fruck , Daniel Galindo , Stefano Gallozzi , Ramon J. García López , Markus Garczarczyk , Markus Gaug , Paola Giammaria , Nikola Godinović , Dariusz Gora , Daniel Guberman , Daniela Hadasch , Alexander Hahn , Tarek Hassan , Masaaki Hayashida , Javier Herrera , Juergen Hose , Dario Hrupec , Susumu Inoue , Kazuma Ishio , Yuki Iwamura , Yusuke Konno , Hidetoshi Kubo , Junko Kushida , Damir Lelas , Elina Lindfors , Saverio Lombardi , Francesco Longo , Marcos López , Camilla Maggio , Pratik Majumdar , Martin Makariev , Galina Maneva , Marina Manganaro , Karl Mannheim , Laura Maraschi , Mosé Mariotti , Manel Martínez , Shu Masuda , Daniel Mazin , Milen Minev , Jose Miguel Miranda , Razmik Mirzoyan , Abelardo Moralejo , Victoria Moreno , Elena Moretti , Tsutomu Nagayoshi , Vitaly Neustroev , Andrzej Niedzwiecki , Mireia Nievas Rosillo , Cosimo Nigro , Kari Nilsson , Daniele Ninci , Kyoshi Nishijima , Koji Noda , Leyre Nogués , Simona Paiano , Joaquim Palacio , David Paneque , Riccardo Paoletti , Josep M. Paredes , Giovanna Pedaletti , Michele Peresano , Massimo Persic , Pier Giorgio Prada Moroni , Elisa Prandini , Ivica Puljak , Jezabel Rodriguez Garcia , Ignasi Reichardt , Wolfgang Rhode , Marc Ribó , Javier Rico , Chiara Righi , Andrea Rugliancich , Takayuki Saito , Konstancja Satalecka , Thomas Schweizer , Julian Sitarek , Iva Snidarić , Dorota Sobczynska , Antonio Stamerra , Marcel Strzys , Tihomir Surić , Mitsunari Takahashi , Fabrizio Tavecchio , Petar Temnikov , Tomislav Terzić , Masahiro Teshima , Nuria Torres-Albà , Aldo Treves , Shimpei Tsujimoto , Gaia Vanzo , Monica Vazquez Acosta , Ievgen Vovk , John E. Ward , Martin Will , Darko Zarić , Matteo Cerruti (1)

1 LPNHE (UMR_7585) - Laboratoire de Physique Nucléaire et de Hautes Énergies

A neutrino with energy ∼290 TeV, IceCube-170922A, was detected in coincidence with the BL Lac object TXS 0506+056 during enhanced gamma-ray activity, with chance coincidence being rejected at ∼3σ level. We monitored the object in the very-high-energy (VHE) band with the Major Atmospheric Gamma-ray Imaging Cherenkov (MAGIC) telescopes for ∼41 hr from 1.3 to 40.4 days after the neutrino detection. Day-timescale variability is clearly resolved. We interpret the quasi-simultaneous neutrino and broadband electromagnetic observations with a novel one-zone lepto-hadronic model, based on interactions of electrons and protons co-accelerated in the jet with external photons originating from a slow-moving plasma sheath surrounding the faster jet spine. We can reproduce the multiwavelength spectra of TXS 0506+056 with neutrino rate and energy compatible with IceCube-170922A, and with plausible values for the jet power of . The steep spectrum observed by MAGIC is concordant with internal γγ absorption above ∼100 GeV entailed by photohadronic production of a ∼290 TeV neutrino, corroborating a genuine connection between the multi-messenger signals. In contrast to previous predictions of predominantly hadronic emission from neutrino sources, the gamma-rays can be mostly ascribed to inverse Compton upscattering of external photons by accelerated electrons. The X-ray and VHE bands provide crucial constraints on the emission from both accelerated electrons and protons. We infer that the maximum energy of protons in the jet comoving frame can be in the range ∼1014 – 1018 eV.

Mots clés: BL Lacertae objects: individual; cosmic rays; galaxies: jets; gamma rays: galaxies; neutrinos; radiation mechanisms: non-thermal; p: energy; electron: interaction; cosmic radiation: acceleration; VHE; gamma ray; photon; MAGIC; Compton scattering: inverse; electromagnetic; absorption; blazar; plasma; X-ray; messenger; neutrino: energy: high

Domaines: Astrophysique [astro-ph]

S. Ansoldi, L.A. Antonelli, Lucio Angelo Antonelli, Cornelia Arcaro, Dominik Baack, et al.. The blazar TXS 0506+056 associated with a high-energy neutrino: insights into extragalactic jets and cosmic ray acceleration. Astrophys.J.Lett., 2018, 863, pp.L10. ⟨10.3847/2041-8213/aad083⟩. ⟨hal-01851257⟩