Gamma-Ray Emission Concurrent with the Nova in the Symbiotic Binary V407 Cygni

• Published in: Science (American Association for the Advancement of Science) Vol. 329; no. 5993; pp. 817 - 821
• Main Authors: Abdo, A. A., Ackermann, M., Ajello, M., Atwood, W. B., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Berenji, B., Blandford, R. D., Bloom, E. D., Bonamente, E., Borgland, A. W., Bouvier, A., Brandt, T. J., Bregeon, J., Brez, A., Brigida, M., Bruel, P., Buehler, R., Burnett, T. H., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Carrigan, S., Casandjian, J. M., Cecchi, C., Çelik, Ö., Charles, E., Chaty, S., Chekhtman, A., Cheung, C. C., Chiang, J., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, J., Corbel, S., Corbet, R., DeCesar, M. E., den Hartog, P. R., Dermer, C. D., de Palma, F., Digel, S. W., Donato, D., do Couto e Silva, E., Drell, P. S., Dubois, R., Dubus, G., Dumora, D., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Fortin, P., Frailis, M., Fuhrmann, L., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Gehrels, N., Germani, S., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I. A., Grondin, M.-H., Grove, J. E., Guiriec, S., Hadasch, D., Harding, A. K., Hayashida, M., Hays, E., Healey, S. E., Hill, A. B., Horan, D., Hughes, R. E., Itoh, R., Jean, P., Jóhannesson, G., Johnson, A. S., Johnson, R. P., Johnson, T. J., Johnson, W. N., Kamae, T., Katagiri, H., Kataoka, J., Kerr, M., Knödlseder, J., Koerding, E., Kuss, M., Lande, J., Latronico, L., Lee, S.-H.
• Format: Journal Article
• Language: English
• Published: Washington, DC American Association for the Advancement of Science 13.08.2010; The American Association for the Advancement of Science; American Association for the Advancement of Science (AAAS); AAAS
• Subjects: Acceleration; ambient air; Astronomical observations; Astronomy; Astrophysics; Binary and multiple stars; Cataclysmic binaries (novae, dwarf novae, recurrent novae, and nova-like objects). Symbiotic stars; Companion stars; controlled study; Decay; Double stars; Earth, ocean, space; Elastic scattering; electric potential; electron; Electrons; Emission; Emissions; Energy; Engineering Sciences; Exact sciences and technology; Explosions; field emission; Fundamental astronomy and astrophysics. Instrumentation, techniques, and astronomical observations; gamma radiation; Gamma ray astronomy; gamma ray radiation; Gamma rays; Gamma-ray sources ; gamma-ray bursts; gas; Inverse; light scattering; molecular interaction; Nova; Novae; numerical model; Observational research; Other; particle size; Physics; priority journal; proton; Protons; radiation energy; Shells; Shock waves; Stars; Stellar systems. Galactic and extragalactic objects and systems. The universe; symbiosis; Symbiotic stars; Thermonuclear explosions; Unidentified sources and radiation outside the solar system; White dwarfs; X-ray; X-rays; γ-ray; Red giant stars; Gamma emission; White dwarf stars; Gamma radiation; Physical model; Inverse Compton scattering; Novae; Symbiotic stars; Mira stars; Gamma decay; Proton-proton interactions
• ISSN: 0036-8075; 1095-9203; 1095-9203
• DOI: 10.1126/science.1192537

Novae are thermonuclear explosions on a white dwarf surface fueled by mass accreted from a companion star. Current physical models posit that shocked expanding gas from the nova shell can produce x-ray emission, but emission at higher energies has not been widely expected. Here, we report the Fermi Large Area Telescope detection of variable γ-ray emission (0.1 to 10 billion electron volts) from the recently detected optical nova of the symbiotic star V407 Cygni. We propose that the material of the nova shell interacts with the dense ambient medium of the red giant primary and that particles can be accelerated effectively to produce π° decay γ-rays from proton-proton interactions. Emission involving inverse Compton scattering of the red giant radiation is also considered and is not ruled out.