# Constraints on gamma-ray and neutrino emission from NGC 1068 with the MAGIC telescopes **Authors:** MAGIC Collaboration: V. A. Acciari (1), S. Ansoldi (2,23), L. A., Antonelli (3), A. Arbet Engels (4), D. Baack (5), A. Babi\'c (6), B. Banerjee, (7), U. Barres de Almeida (8), J. A. Barrio (9), J. Becerra Gonz\'alez (1),, W. Bednarek (10), L. Bellizzi (11), E. Bernardini (12,16), A. Berti (13), J., Besenrieder (14), W. Bhattacharyya (12), C. Bigongiari (3), A. Biland (4), O., Blanch (15), G. Bonnoli (11), \v{Z}. Bo\v{s}njak (6), G. Busetto (16), R., Carosi (17), G. Ceribella (14), Y. Chai (14), A. Chilingaryan (18), S. Cikota, (6), S. M. Colak (15), U. Colin (14), E. Colombo (1), J. L. Contreras (9), J., Cortina (19), S. Covino (3), V. D'Elia (3), P. Da Vela (17), F. Dazzi (3), A., De Angelis (16), B. De Lotto (2), M. Delfino (15,26), J. Delgado (15,26), D., Depaoli (13), F. Di Pierro (13), L. Di Venere (13), E. Do Souto Espi\~neira, (15), D. Dominis Prester (6), A. Donini (2), D. Dorner (20), M. Doro (16), D., Elsaesser (5), V. Fallah Ramazani (21), A. Fattorini (5), G. Ferrara (3), D., Fidalgo (9), L. Foffano (16), M. V. Fonseca (9), L. Font (22), C. Fruck (14),, S. Fukami (23), R. J. Garc\'ia L\'opez (1), M. Garczarczyk (12), S. Gasparyan, (18), M. Gaug (22), N. Giglietto (13), F. Giordano (13), N. Godinovi\'c (6),, D. Green (14), D. Guberman (15), D. Hadasch (23), A. Hahn (14), J. Herrera, (1), J. Hoang (9), D. Hrupec (6), M. H\"utten (14), T. Inada (23), S. Inoue, (23), K. Ishio (14), Y. Iwamura (23), L. Jouvin (15), D. Kerszberg (15), H., Kubo (23), J. Kushida (23), A. Lamastra (3), D. Lelas (6), F. Leone (3), E., Lindfors (21), S. Lombardi (3), F. Longo (2,27), M. L\'opez (9), R., L\'opez-Coto (16), A. L\'opez-Oramas (1), S. Loporchio (13), B. Machado de, Oliveira Fraga (8), C. Maggio (22), P. Majumdar (7), M. Makariev (24), M., Mallamaci (16), G. Maneva (24), M. Manganaro (6), K. Mannheim (20), L., Maraschi (3), M. Mariotti (16), M. Mart\'inez (15), D. Mazin (14,23), S., Mi\'canovi\'c (6), D. Miceli (2), M. Minev (24), J. M. Miranda (11), R., Mirzoyan (14), E. Molina (25), A. Moralejo (15), D. Morcuende (9), V. Moreno, (22), E. Moretti (15), P. Munar-Adrover (22), V. Neustroev (21), C. Nigro, (12), K. Nilsson (21), D. Ninci (15), K. Nishijima (23), K. Noda (23), L., Nogu\'es (15), S. Nozaki (23), S. Paiano (16), J. Palacio (15), M. Palatiello, (2), D. Paneque (14), R. Paoletti (11), J. M. Paredes (25), P. Pe\~nil (9),, M. Peresano (2), M. Persic (2,28), P. G. Prada Moroni (17), E. Prandini (16),, I. Puljak (6), W. Rhode (5), M. Rib\'o (25), J. Rico (15), C. Righi (3), A., Rugliancich (17), L. Saha (9), N. Sahakyan (18), T. Saito (23), S. Sakurai, (23), K. Satalecka (12), K. Schmidt (5), T. Schweizer (14), J. Sitarek (10),, I. \v{S}nidari\'c (6), D. Sobczynska (10), A. Somero (1), A. Stamerra (3), D., Strom (14), M. Strzys (14), Y. Suda (14), T. Suri\'c (6), M. Takahashi (23),, F. Tavecchio (3), P. Temnikov (24), T. Terzi\'c (6), M. Teshima (14,23), N., Torres-Alb\`a (25), L. Tosti (13), V. Vagelli (13), J. van Scherpenberg (14),, G. Vanzo (1), M. Vazquez Acosta (1), C. F. Vigorito (13), V. Vitale (13), I., Vovk (14), M. Will (14), D. Zari\'c (6), and F. Fiore (34), C. Feruglio (34),, Y. Rephaeli (35,36) arXiv: 1906.10954 · 2020-01-27 ## TL;DR This study used MAGIC telescopes to search for very high energy gamma-ray emission from NGC 1068, setting new upper limits that constrain theoretical models and predicting neutrino detection prospects. ## Contribution First deep VHE gamma-ray observational limits on NGC 1068, constraining hadronic emission models and supporting leptonic scenarios. ## Key findings - No significant gamma-ray detection above 200 GeV. - Upper limits improve previous constraints by an order of magnitude. - Predicted neutrino event rate is up to 0.07 per year. ## Abstract Starburst galaxies and star-forming active galactic nuclei (AGN) are among the candidate sources thought to contribute appreciably to the extragalactic gamma-ray and neutrino backgrounds. NGC 1068 is the brightest of the star-forming galaxies found to emit gamma rays from 0.1 to 50 GeV. Precise measurements of the high-energy spectrum are crucial to study the particle accelerators and probe the dominant emission mechanisms. We have carried out 125 hours of observations of NGC 1068 with the MAGIC telescopes in order to search for gamma-ray emission in the very high energy band. We did not detect significant gamma-ray emission, and set upper limits at 95\% confidence level to the gamma-ray flux above 200 GeV f<5.1x10^{-13} cm^{-2} s ^{-1} . This limit improves previous constraints by about an order of magnitude and allows us to put tight constraints on the theoretical models for the gamma-ray emission. By combining the MAGIC observations with the Fermi-LAT spectrum we limit the parameter space (spectral slope, maximum energy) of the cosmic ray protons predicted by hadronuclear models for the gamma-ray emission, while we find that a model postulating leptonic emission from a semi-relativistic jet is fully consistent with the limits. We provide predictions for IceCube detection of the neutrino signal foreseen in the hadronic scenario. We predict a maximal IceCube neutrino event rate of 0.07 yr^{-1}. ## Full text _Full body text omitted from this summary view._ Fetch the complete paper as Markdown: https://tomesphere.com/paper/1906.10954/full.md ## Figures 6 figures with captions in the complete paper: https://tomesphere.com/paper/1906.10954/full.md ## References 70 references — full list in the complete paper: https://tomesphere.com/paper/1906.10954/full.md --- Source: https://tomesphere.com/paper/1906.10954