Attila Abramowski, Felix A. Aharonian, Faical Ait Benkhali, A. G. Akhperjanian, Ekrem Oǧuzhan Angüner, Michael Backes, Arnim Balzer, Yvonne Becherini, J. Becker Tjus, David Berge, Sabrina Bernhard, K. Bernlöhr, E. Birsin, R. Blackwell, Markus Boettcher, Catherine Boisson, J. Bolmont, Pol Bordas, Johan Bregeon, Francois Brun, Pierre Brun, Mark Bryan, Tomasz Bulik, John Carr, Sabrina Casanova, N. Chakraborty, R. Chalme-Calvet, Ryan C. G. Chaves, Andrew Chen, M. Chretien, Sergio Colafrancesco, Gabriele Cologna, Jan Conrad, C. Couturier, Y. Cui, I. D. Davids, B. Degrange, C. Deil, P. deWilt, A. Djannati-Ata, W. Domainko, A. Donath, G. Dubus, K. Dutson, J. Dyks, M. Dyrda, T. Edwards, Kathrin Egberts, P. Eger, J-P. Ernenwein, P. Espigat, C. Farnier, S. Fegan, F. Feinstein, M. V. Fernandes, D. Fernandez, A. Fiasson, G. Fontaine, A. Foerster, M. Fuessling, S. Gabici, M. Gajdus, Y. A. Gallant, T. Garrigoux, G. Giavitto, B. Giebels, J. F. Glicenstein, D. Gottschall, A. Goyal, M-H. Grondin, M. Grudzinska, D. Hadasch, S. Haeffner, J. Hahn, J. Hawkes, G. Heinzelmann, G. Henri, G. Hermann, O. Hervet, A. Hillert, James Anthony Hinton, W. Hofmann, P. Hofverberg, Clemens Hoischen, M. Holler, D. Horns, A. Ivascenko, A. Jacholkowska, M. Jamrozy, M. Janiak, F. Jankowsky, I. Jung-Richardt, M. A. Kastendieck, K. Katarzynski, U. Katz, D. Kerszberg, B. Khelifi, M. Kieffer, S. Klepser, D. Klochkov, W. Kluzniak, D. Kolitzus, Nu. Komin, K. Kosack, S. Krakau, F. Krayzel, P. P. Krueger, H. Laffon, G. Lamanna, J. Lau, J. Lefaucheur, V. Lefranc, A. Lemiere, M. Lemoine-Goumard, J-P. Lenain, T. Lohse, A. Lopatin, C-C. Lu, R. Lui, V. Marandon, A. Marcowith, C. Mariaud, R. Marx, G. Maurin, N. Maxted, M. Mayer, P. J. Meintjes, U. Menzler, M. Meyer, A. M. W. Mitchell, R. Moderski, M. Mohamed, K. Mora, E. Moulin, T. Murach, M. de Naurois, J. Niemiec, L. Oakes, H. Odaka, S. Oettl, S. Ohm, B. Opitz, M. Ostrowski, I. Oya, M. Panter, R. D. Parsons, M. Paz Arribas, N. W. Pekeur, G. Pelletier, P-O. Petrucci, B. Peyaud, S. Pita, H. Poon, H. Prokoph, G. Puehlhofer, M. Punch, A. Quirrenbach, S. Raab, I. Reichardt, A. Reimer, O. Reimer, M. Renaud, R. de los Reyes, F. Rieger, C. Romoli, S. Rosier-Lees, G. Rowell, B. Rudak, C. B. Rulten, V. Sahakian, D. Salek, David M. Sanchez, A. Santangelo, M. Sasaki, R. Schlickeiser, F. Schuessler, A. Schulz, U. Schwanke, S. Schwemmer, A. S. Seyffert, R. Simoni, H. Sol, F. Spanier, G. Spengler, F. Spies, L. Stawarz, R. Steenkamp, Christian Stegmann, F. Stinzing, K. Stycz, Iurii Sushch, J-P. Tavernet, T. Tavernier, A. M. Taylor, R. Terrier, M. Tluczykont, C. Trichard, R. Tuffs, K. Valerius, J. van der Walt, C. van Eldik, B. van Soelen, G. Vasileiadis, J. Veh, C. Venter, A. Viana, P. Vincent, J. Vink, F. Voisin, H. J. Voelk, T. Vuillaume, S. J. Wagner, P. Wagner, R. M. Wagner, M. Weidinger, Q. Weitzel, R. White, A. Wierzcholska, P. Willmann, A. Woernlein, D. Wouters, R. Yang, V. Zabalza, D. Zaborov, M. Zacharias, A. A. Zdziarski, Alraune Zech, F. Zefi, N. Zywucka

• Galactic cosmic rays reach energies of at least a few petaelectronvolts (of the order of 1015 electronvolts). This implies that our Galaxy contains petaelectronvolt accelerators (‘PeVatrons’), but all proposed models of Galactic cosmic-ray accelerators encounter difficulties at exactly these energies. Dozens of Galactic accelerators capable of accelerating particles to energies of tens of teraelectronvolts (of the order of 1013 electronvolts) were inferred from recent γ-ray observations3. However, none of the currently known accelerators—not even the handful of shell-type supernova remnants commonly believed to supply most Galactic cosmic rays—has shown the characteristic tracers of petaelectronvolt particles, namely, power-law spectra of γ-rays extending without a cut-off or a spectral break to tens of teraelectronvolts4. Here we report deep γ-ray observations with arcminute angular resolution of the region surrounding the Galactic Centre, which show the expected tracer of the presence of petaelectronvolt protonsGalactic cosmic rays reach energies of at least a few petaelectronvolts (of the order of 1015 electronvolts). This implies that our Galaxy contains petaelectronvolt accelerators (‘PeVatrons’), but all proposed models of Galactic cosmic-ray accelerators encounter difficulties at exactly these energies. Dozens of Galactic accelerators capable of accelerating particles to energies of tens of teraelectronvolts (of the order of 1013 electronvolts) were inferred from recent γ-ray observations3. However, none of the currently known accelerators—not even the handful of shell-type supernova remnants commonly believed to supply most Galactic cosmic rays—has shown the characteristic tracers of petaelectronvolt particles, namely, power-law spectra of γ-rays extending without a cut-off or a spectral break to tens of teraelectronvolts4. Here we report deep γ-ray observations with arcminute angular resolution of the region surrounding the Galactic Centre, which show the expected tracer of the presence of petaelectronvolt protons within the central 10 parsecs of the Galaxy. We propose that the supermassive black hole Sagittarius A* is linked to this PeVatron. Sagittarius A* went through active phases in the past, as demonstrated by X-ray outbursts5and an outflow from the Galactic Centre6. Although its current rate of particle acceleration is not sufficient to provide a substantial contribution to Galactic cosmic rays, Sagittarius A* could have plausibly been more active over the last 106–107 years, and therefore should be considered as a viable alternative to supernova remnants as a source of petaelectronvolt Galactic cosmic rays.…