The blazar TXS 0506+056 associated with a high-energy neutrino: insights into extragalactic jets and cosmic ray acceleration
Creators: name: Ansoldi, S.
name: Antonelli, L. A.
name: Arcaro, C.
name: Baack, D.
name: Babić, A.
name: Banerjee, B.
name: Bangale, P.
name: de Almeida, U. Barres
name: Barrio, J. A.
name: González, J. Becerra
name: Bednarek, W.
name: Bernardini, E.
name: Berse, R. Ch.
name: Berti, A.
name: Besenrieder, J.
name: Bhattacharyya, W.
name: Bigongiari, C.
name: Biland, A.
name: Blanch, O.
name: Bonnoli, G.
name: Carosi, R.
name: Ceribella, G.
name: Chatterjee, A.
name: Colak, S. M.
name: Colin, P.
name: Colombo, E.
name: Contreras, J. L.
name: Cortina, J.
name: Covino, S.
name: Cumani, P.
name: D'Elia, V.
name: Da Vela, P.
name: Dazzi, F.
name: De Angelis, A.
name: De Lotto, B.
name: Delfino, M.
name: Delgado, J.
name: Di Pierro, F.
name: Domínguez, A.
name: Prester, D. Dominis
name: Dorner, D.
name: Doro, M.
name: Einecke, S.
name: Elsaesser, D.
name: Ramazani, V. Fallah
name: Fattorini, A.
name: Fernández-Barral, A.
name: Ferrara, G.
name: Fidalgo, D.
name: Foffano, L.
name: Fonseca, M. V.
name: Font, L.
name: Fruck, C.
name: Gallozzi, S.
name: López, R. J. García
name: Garczarczyk, M.
name: Gaug, M.
name: Giammaria, P.
name: Godinović, N.
name: Guberman, D.
name: Hadasch, D.
name: Hahn, A.
name: Hassan, T.
name: Hayashida, M.
name: Herrera, J.
name: Hoang, J.
name: Hrupec, D.
name: Inoue, S.
name: Ishio, K.
name: Iwamura, Y.
name: Konno, Y.
name: Kubo, H.
name: Kushida, J.
name: Lamastra, A.
name: Lelas, D.
name: Leone, F.
name: Lindfors, E.
name: Lombardi, S.
name: Longo, F.
name: López, M.
name: Maggio, C.
name: Majumdar, P.
name: Makariev, M.
name: Maneva, G.
name: Manganaro, M.
name: Mannheim, K.
name: Maraschi, L.
name: Mariotti, M.
name: Martínez, M.
name: Masuda, S.
name: Mazin, D.
name: Mielke, K.
name: Minev, M.
name: Miranda, J. M.
name: Mirzoyan, R.
name: Moralejo, A.
name: Moreno, V.
name: Moretti, E.
name: Neustroev, V.
name: Niedzwiecki, A.
name: Rosillo, M. Nievas
name: Nigro, C.
name: Nilsson, K.
name: Ninci, D.
name: Nishijima, K.
name: Noda, K.
name: Nogués, L.
name: Paiano, S.
name: Palacio, J.
name: Paneque, D.
name: Paoletti, R.
name: Paredes, J. M.
name: Pedaletti, G.
name: Peñil, P.
name: Peresano, M.
name: Persic, M.
name: Pfrang, K.
name: Moroni, P. G. Prada
name: Prandini, E.
name: Puljak, I.
name: Garcia, J. R.
name: Rhode, W.
name: Ribó, M.
name: Rico, J.
name: Righi, C.
name: Rugliancich, A.
name: Saha, L.
name: Saito, T.
name: Satalecka, K.
name: Schweizer, T.
name: Sitarek, J.
name: Šnidarić, I.
name: Sobczynska, D.
name: Stamerra, A.
name: Strzys, M.
name: Surić, T.
name: Tavecchio, F.
name: Temnikov, P.
name: Terzić, T.
name: Teshima, M.
name: Torres-Albà, N.
name: Tsujimoto, S.
name: Vanzo, G.
name: Acosta, M. Vazquez
name: Vovk, I.
name: Ward, J. E.
name: Will, M.
name: Zarić, D.
name: Cerruti, Matteo
Publisher: name: arXiv
Year: 2018
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: A neutrino with energy of $\sim$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 $\sim 3σ$ level. We monitored the object in the very-high-energy (VHE) band with the MAGIC telescopes for $\sim$41 hours 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 $\sim 10^{45} - 4 \times 10^{46} {\rm erg \ s^{-1}}$. The steep spectrum observed by MAGIC is concordant with internal $γγ$ absorption above a few tens of GeV entailed by photohadronic production of a $\sim$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 up-scattering 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 co-moving frame can be in the range $\sim 10^{14}$ to $10^{18}$ eV.
description: 11 pages, 3 figues, 3 tables, Accepted for publication in ApJL. Major changes in the revised Version: corrected author list