Extreme particle acceleration in the microquasar Cygnus X-3

M. Tavani, A. Bulgarelli, G. Piano, S. Sabatini, E. Striani, Y. Evangelista, A. Trois, G. Pooley, S. Trushkin, N.A. Nizhelskij, M. McCollough, K.I.I. Koljonen, G. Pucella, A. Giuliani, A.W. Chen, E. Costa, V. Vittorini, M. Trifoglio, F. Gianotti, A. ArganG. Barbiellini, P. Caraveo, P.W. Cattaneo, V. Cocco, T. Contessi, F. Dĝammando, E. Del Monte, G. De Paris, G. Di Cocco, G. Di Persio, I. Donnarumma, M. Feroci, A. Ferrari, F. Fuschino, M. Galli, C. Labanti, I. Lapshov, F. Lazzarotto, P. Lipari, F. Longo, E. Mattaini, M. Marisaldi, M. Mastropietro, A. Mauri, S. Mereghetti, E. Morelli, A. Morselli, L. Pacciani, A. Pellizzoni, F. Perotti, P. Picozza, M. Pilia, M. Prest, M. Rapisarda, A. Rappoldi, E. Rossi, A. Rubini, E. Scalise, P. Soffitta, E. Vallazza, S. Vercellone, A. Zambra, D. Zanello, C. Pittori, F. Verrecchia, P. Giommi, S. Colafrancesco, P. Santolamazza, A. Antonelli, L. Salotti

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Super-massive black holes in active galaxies can accelerate particles to relativistic energies, producing jets with associated γ-ray emission. Galactic ĝ€ microquasarsĝ€™, which are binary systems consisting of a neutron star or stellar-mass black hole accreting gas from a companion star, also produce relativistic jets, generally together with radio flares. Apart from an isolated event detected in Cygnus X-1, there has hitherto been no systematic evidence for the acceleration of particles to gigaelectronvolt or higher energies in a microquasar, with the consequence that we are as yet unsure about the mechanism of jet energization. Here we report four γ-ray flares with energies above 100 MeV from the microquasar Cygnus X-3 (an exceptional X-ray binary that sporadically produces radio jets). There is a clear pattern of temporal correlations between the γ-ray flares and transitional spectral states of the radio-frequency and X-ray emission. Particle acceleration occurred a few days before radio-jet ejections for two of the four flares, meaning that the process of jet formation implies the production of very energetic particles. In Cygnus X-3, particle energies during the flares can be thousands of times higher than during quiescent states. © 2009 Macmillan Publishers Limited. All rights reserved.
Original languageEnglish
Pages (from-to)620 - 623
Number of pages4
Issue number7273
Publication statusPublished - 3 Dec 2009
Externally publishedYes


All Science Journal Classification (ASJC) codes

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Cite this

Tavani, M., Bulgarelli, A., Piano, G., Sabatini, S., Striani, E., Evangelista, Y., Trois, A., Pooley, G., Trushkin, S., Nizhelskij, N. A., McCollough, M., Koljonen, K. I. I., Pucella, G., Giuliani, A., Chen, A. W., Costa, E., Vittorini, V., Trifoglio, M., Gianotti, F., ... Salotti, L. (2009). Extreme particle acceleration in the microquasar Cygnus X-3. Nature, 462(7273), 620 - 623. https://doi.org/10.1038/nature08578